The Portuguese DISASTER...

Posted by Nima On Thursday, September 17, 2009 94 comments

Ahoy Paleo Fans! It's been a hectic past few months in the Paleo Kingdom, and the fruits of my labor will soon be posted here for all to see.

But first I think the more loyal ones among you will be interested in something that was far more hidden - indeed, it's a piece of paleo-art that ALMOST didn't get made.

Back in April I first heard of the 9th International Dinosaur Illustration contest sponsored by the Museu da Lourinhã in Portugal. Now of course I was ecstatic. Paleo-art (or if you prefer, paleontography, though that term apparently means something else in cheesy online dictionaries) is not often the subject of a real competition. Serious paleo-art contests open to anyone above 15 years of age are extremely rare and hard to come by.

I don't know why this is (and I certainly don't approve of this dismal state of affairs) but it may be that the mainstream art world has yet to truly understand dinosaurs as high art. To you and I, Bakker and Paul may be the Michelangelos of our time (and to some, Raúl Martín would undoubtedly be our modern Vasari), but you would never know it from the scores of snobbish art critics that pay them no mind. Dinosaurs ARE high art if they are done right and with style, the problem is that so few people do them right to begin with, before you can even GET to the style issue - especially illustrators that get PAID to fill the pages of dinosaur books for big publishers. Most of them are part-time nature artists with very little knowledge of dinosaur anatomy or ecosystems... so they simply copy older books, the paleontologist who works as "consultant" or "author" for the book doesn't bother to correct them (yes I have a wall of shame but I won't post it here... I can't exhaust all the fun just now!) - and then we end up with silly but persistent follies like sauropods with elephants' hands, T.rexes dragging their tails, duckbills with webbed feet, ceratopsians with the tail FAR too long, and diplodocids with a camarasaur head (yes, some artists STILL draw them this way - i.e. look for Barosaurus in Dr. Michael Benton's Dinosaur Factfinder...)

So naturally when I did find a contest where SERIOUS dinosaur art was seriously considered to win prize money, I thought this must be my lucky day! Now as it turned out it wasn't that easy.

You basically have to mail your drawings to the Museu da Lourinhã... which means -you guessed it - INTERNATIONAL POSTAGE. I don't want to go into debates about the nuances of the special shipping deals of Priority Mail vs. UPS vs. DHL... I don't have ANY interest in quibbling over corporate differences, so don't say "you could have used these guys, they make it easy..." as I've already looked at the options and it's a hassle any way you cut it.


But it was a worthy hassle, I thought. I could win 1000 Euros... which would be more when you convert them into dollars... and even though that's hardly a fortune, simply winning first prize would guarantee a bit of fame... since this is THE only international dinosaur art competition open to all adults worldwide, it's a good way to make a name for yourself... previous contestants have included Alain Bénéteau and Andrei Atuchin, as well as the ever more popular Luis Rey.

So I started the drawing with a little over a month left till that ominous deadline... But I hadn't factored in that the month in question was also a month of nerve-wracking studying and memorization to prepare for college finals! And as any of you who have been to a big public university know, professors and T.A.'s are overwhelmed and don't really have much time to answer EVERY student's every question... (plus I could swear that some of mine were stoned... you couldn't even get a straight answer out of them by offering to sleep with the dean and get them that precious raise they've been craving even more than their pot, in exchange for one measly practice final solution* - not that I would do such a thing, nor have any of our deans, at any rate, had even a trace of the extreme beauty needed to tempt one to risk it!)

*A word to the not-so-wise: "practice final solution" in this context means a solution to a problem on a practice final exam, not some macabre test run for a second holocaust... sheesh, you wouldn't believe how many pathologically sick people there are on teh interwebz these days.

Now putting the academic stuff aside for a minute, there was also the driving factor that the judges of the contest would prefer either dinosaurs in their natural habitat, OR Portuguese dinosaurs. So I decided to do a combination of both. I ended up researching a bunch of Portuguese dinosaurs from the Late Jurassic Lourinhã formation, and even doing several rough profile sketches of them. One was this baby right here - you may have seen this Dacentrurus in a previous post (albeit with a better scale bar and any hints of the creature's identity erased):
I almost NEVER do rough sketches of dinosaurs unless I TRULY have no immediate plans for them... These days, after years of experience learning the ins and outs of paleo-art, I usually visualize the completed work for a while and then simply draw it without errors (at least for the species I'm familiar with)... some friends have compared me to Mozart, but I won't be that boastful. Though I DO prefer to have things done right (or close to it) the first time, as even having to make major corrections is less tedious to me than starting again from scratch. Nevertheless, I did several very rough and preliminary sketches of Dacentrurus and Torvosaurus, and even of Lusotitan, which I assume wasn't all that different from Brachiosaurus.

And because of the messy situation with studying for finals (compounded by a MAJOR unforeseen shortage in the supply of textbooks at the start of that quarter, the price of whose mismanagement by negligent administrators we were still paying for...) ...... most of my time was ruthlessly devoured by academics, and all I was able to produce by the time finals rolled around was THIS:



Two Dacentrurus armatus face down an attack by three Torvosaurus tanneri near the edge of a forest in Lourinhã... (well, it was supposed to be a forest... I only had a couple of conifers done by finals week). The rear perspective was quite tricky, especially with the foreshortening of the tail on the individual on the right - but this served as a good study for future rear perspective drawings. Of course, my "studies" are not content simply to be studies, but often inexorably end up as finished products in their own right.

There were a lot of challenges present in this piece - from drawing the oddly proportioned Torvosaurs (which I had never drawn or even studied before) to getting the correct perspective and angles for the Dacentrurus tail spikes. And then there was the whole crazy "splattering flesh" effect from a deadly Dacentrurus blow. How were the physics of such a tearing impact supposed to work? I wrangled with the idea on and off for over a week. However, after finals there was much more free time to work on this drawing and really make it presentable.



Okay, NOW there are more trees, lots of dust, some big Lusotitans and a Miragaia in the background. I really used eraser techniques to the max here. You have to with this crazy printer paper, it has next to no texture so to avoid "clutter" you have to lighten the "foggier" background with "eraser tamping". I swore this was the last time I'd use cheap, textureless printer paper for a paleo drawing, but then I realized my store of textured heavy paper had run out, and I ended up using this same annoying paper for two of my three recent pterosaur drawings! They came out looking good, but would have almost certainly been better on heavy paper. I later went out and bought a new sketchbook with detachable sheets, but I still prefer the texture of the slightly pricier heavy printer paper (the sort used for legal documents and the like). Every scale, every detail proved FAR more difficult to draw realistically on this cheap printer paper. And once you start drawing in one style, you can't skimp out and finish the rest in plain gray tones without scales! For my Styracosaurus herd drawing I'd had plenty of time to prepare, and lots of free hours without looming exams approaching. No such good fortune here.

But then, another problem reared its ugly head to bite me. The mother of all setbacks... I had passed the deadline for the submission, May 31. Man I HATE all the stress that final exams put you through. It's as if the rest of life gets put on hold, normally important things become a waste of valuable time and everything begins to balk - especially your notebooks, calculator batteries, and neurons. The deadline passed before the finals themselves did. And the prep work ate up all of my time (though it certainly paid off).

Now in hindsight, missing that deadline was not the end of the world, and it's not exactly vital to anyone's future... but at that exact moment I felt like burning the damn drawing that had taken so long to progress! I slowly had to accept the fact that the submission would have to wait until next year's contest. And it's not exactly like there are a lot of other serious dino-art contests during the year open to people my age and not dependent on where I live. (Lol, what would we competitive-spirited paleo-artists do without the Museum of Lourinhã?) Yet I wish they had chosen a better date. Something a bit more college-friendly... So this drawing almost sat idle to be forgotten, when I had the not-so-eccentric idea of just finishing it ANYWAY.

It was already half-done. I was already in the mood for drawing all those tiny scales (a decision whose tedious execution had almost made me regret the whole thing at first)... so I figured, what the hell, stop complaining and finish that sucker! And before long, this "Portuguese disaster" actually came out pretty good!



Here's the final version. And it's a very detailed piece in its own right, but it would have totally made my day to be able to mail it to Portugal on time and find that it at least won an honorable mention or something of the sort. I did not even count the scales. Merely to look at them now makes my head spin. It would have been a breeze by comparison, if I'd had better paper. Now that I have it in spades, things should go a lot faster and easier and with better results - though despite the initial disaster with the contest's deadline and the rush of finals, the results here are actually pretty nice. It could use a slight touch up (which I may get around to soon) - but still, it came out way better than I expected.

And what's the story behind the story? Dacentrurus was a fairly primitive and long-surviving genus of stegosaur. It was possibly also the largest member of the family, with some specimens apparently exceeding Stegosaurus by around half a meter. It's thus odd that many artists (John Sibbick is a notable example) restore it as a dwarf stegosaur in light of this stark fact. It's also unlikely that Dacentrurus was entirely armed with spikes - its front half likely also had small plates and shoulder spikes like those of its smaller cousin Kentrosaurus (painting by Jim Robins). In fact I drew the armor configuration very similar to Kentrosaurus, except that there are four thick "anvil" spikes over the hips having uniform enlarged thickness and being very unlike the plates, and also unlike the tail spikes. Also the body plan is different from Kentrosaurus, having longer front legs and a straighter back. As stegosaurs continued to evolve, they seem to have reduced the arms and shortened the torso, putting more emphasis on the hips. But it's likely that even the big, longer-armed Dacentrurus was capable of rearing much like its more light-fronted successors. The tail was definitely a more effective all-purpose weapon against big predators than that of Stegosaurus - it had nearly four times as many spikes! This may explain why Dacentrurus survived so long, but there's another possibility:

All of the rather fragmentary remains of Dacentrurus may belong to several separate genera of stegosaurs that lived at different times in the mid to late Jurassic. That's right, this guy's not that well understood, and that's a welcome challenge. Not everybody draws Dacentrurus, and far fewer draw it well. These dinosaurs will have their day, as next year's competition draws near... and better late than never, they're finally done.

94 comments:

Michael O. Erickson said...

Wow, great work Nima! The composition is amazing. That torvosaur is having an awfully bad day...

Usually when I see a peice of paleoart, first I sit back and admire it, then I go in and slam on all of the inaccuracies. Thankfully, I rarely have to do the later in your artwork!

However, there are two points I would like to make if that's okay. For starters, Miragaia and Dacentrurus may actually be same animal. Adam Yates makes a good case for this here:

http://dracovenator.blogspot.com/2009_02_01_archive.html

The other point I would like to make is that the one torvosaur (the one with its mouth closed) has its teeth hanging out. Now, I don't care what Tracy Ford and Larry Witmer say, theropods had lips! The evidence for lips is excellent and as far as I'm concerned it shouldn't even be a matter of debate. I know the teeth of Torvosaurus are really big, so it may sound logical to have them hanging out from under the lips. But this isn't so, judging from modern lizards that have huge sharp teeth (like slow worms and Gila monsters). In these animals, the teeth are completely hidden by the lips when the jaws closed. Greg paul has done two good drawings of Tyrannosaurus that show this:

http://i663.photobucket.com/albums/uu360/Dinogeek/ZZZZZZZZZZZZZZZZZZZZZZZZ.jpg

http://i663.photobucket.com/albums/uu360/Dinogeek/ZZZZZZZZZZZZZZZZZZZZZZZ.jpg

Well, that's it, sorry if my comment is annoying. Keep up the great work!

Michael O. Erickson said...

That's odd, those links don't work. Sorry.

You can see the two Grag Paul pics here:

http://s663.photobucket.com/albums/uu360/Dinogeek/

Michael O. Erickson said...

That link didn't work either? Oh, I give up. I tried.

Nima said...

Lol it's alright Michael. You can email me copies of the images at Nima_Sassani@yahoo.com.

I have great respect for Greg Paul as well as the intellectual property rights of artists in general, so I wouldn't use them for any sort of personal gain. I might even feature them in a later post if this lips issue proves controversial enough!

I'm curious about the whole lips thing, because I've seen Greg Paul's T.rex restorations showing teeth even WITH the lips. Yes theropods had lips, and in fact I thought I was drawing enough lip on these guys... I don't agree with Larry Witmer either (especially not regarding sauropod noses) but a lack of lips was never my intention.

Now I have read and reread Bakker's chapter on dinosaur lips many times, and I'm aware that deep lip holes along the dentary and the mandibular indicate large muscular lips. And with animals like T.rex this is certainly the case. But it's NOT the case with Torvosaurus!

Looking at the skull of Torvosaurus I see almost completely SMOOTH dentaries with no lip holes, and a few holes in odd whisker-like positions near the front of the maxilla, so yes it certainly had lips but not as big or extensive as T.rex lips. The teeth are so huge that in my view they would stick out beyond the lips. Perhaps I made the lips a bit too minimal, but I doubt they were very big or could fully cover those massive teeth, given the fossil evidence.

As for Miragaia and Dacentrurus, there's a chance they could be the same (they're certainly related) but I wouldn't jump the gun on that one so quickly. Some of the Dacentrurus remains indicate a substantially larger animal than Miragaia. The tricky part is that most of the remains assigned to Dacentrurus are of various sizes and morphotypes, and are either non-diagnostic or insufficiently described. They probably represent three or more genera. So SOME of them might actually belong to Miragaia or something similar, but that does not invalidate the entire genus Dacentrurus in my view.

Michael O. Erickson said...

I'll send you the Paul pics in the minute.

About the Torvosaurus lip issue, I took another good look (the key word there is GOOD - I've looked at it before but not in much detail), and you are 100% correct with regard to the smoothness of the facial bones. The lips of a torvosaur do indeed appear to have been rather minimal, especially compared to T. rex, which probably had big thick Komodo-dragon style lips (as shown in Bakker's book). So to sum up I no longer think you have made any sort of error there.

Regarding the two stegosaurs, I never actually intended to say that you were likely incorrect by showing Dacentrurus and Miragaia as two different animals - I just wanted to let you know in case you unaware about the debate.

Thanks!

Michael O. Erickson said...

The more I look at that picture though, the more I love it. I mean really, it's just freakin' awesome, totally. I especially like the foreshortened tail efect on the Dacentrurus at the right.

Zach Armstrong said...

Nima, you certainly have a flair doing dinosaur scenes that I do not possess. I simply do not have the patience to work on a drawing for longer than a week.

Just a curious art-related question: how large of a sheet did you use for this, if you don't mind my asking?

I would have to agree with M.O. above about the Dacentrurus likely being the same as Miragaia. It does appear that Miragaia may have been smaller (around 4 m) compared to 9 or 10 m for Dacentrurus, but, as far as I know, we do not know how old the Miragaia specimen was, so it could be a subadult or juvenile. It also appears that there is a large variation in the size of Dacentrurus, anywhere from 6 to 10 m long for an adult. At any rate, they were found to be VERY closely related, and are known from the same geographic location. But, as always, we must wait for better to material to clear that up.

Now, as for theropod lips, I used to be of the opinion that theropods MUST have had lips (and in fact discussed at length this topic with Tracy Ford), but now I am not so sure. Some have made pretty convincing arguments that the lip 'holes' that are along the jaws are no such thing, but merely housed sensory organs (like in crocodiles).If you copy-and-paste this (http://www.agassiztrading.com/photos/photos-boneroom/croc-skull1-3.jpg) link into your browser, you'll see what I mean by crocodiles' 'holes'. Furthermore, there are the practical elements to consider: what would the lips have been USED for? Theropod teeth seem in the majority of cases to large to have fit nice and easily into lip coverings. If you look at lizard skulls, their teeth are far smaller proportionally to their skulls than most theropods, especially in the relative diameter of the teeth. If theropod lips were to cover their teeth they would have had to have been VERY deep, and the 'holes' don't indicate lips that deep, so it does call into question if theropods had lips, and to what extent they covered the teeth if they did have them.

As for Witmer's sauropod noses, what's wrong with 'em??

And finally, let me say that your illustration is GREAT. Good job!

Michael O. Erickson said...

No, sorry, theropods had lips. The jaw "holes" of theropods are NOTHING like the "holes" of crocodiles. Croc holes are scattered willy-nilly around the jaw bones, whereas theropod holes are arranged in even rows - EXACTLY like the "lip holes" of squamates. Also, crocodile sensory organs are for "feeling" the movements of prey UNDERWATER. I wouldn't think a land-dwelling theropod would have had such a thing, as it would simply wouldn't function out of water. And if the "sensory organ" thing WERE the case, why don't theropod holes agree with croc holes? Why are they instead, in looks and in arrangement, identical to lizard holes (which, incidentally, supply nerves to the lips)? Anyone wanting to refute theropod lips MUST explain why theropod holes look like lizard holes rather than croc holes - and interestingly no anti-lips person ever has.

As for WHY theropods would have lips, a much better question would be why they WOULDN'T have had them - crocs are weird among extant vertebrates in NOT having lips. And considering that amphibians posess lips, even without the sound osteological evidence our null hypothesis should be "lips" anyway.

As for Witmer's sauropod noses, what's wrong with them can be summed up in one word - EVERYTHING. Email Nima for details (which is actually what I did!).

And to clarify, if this comment sounds like I'm angry or something (which I can tell it might), I assure you that isn't the case.

Nima said...

Let ME weigh in here. There is a very big difference between theropod lip holes and the little dimple-like holes on crocodile skulls.

But first, thanks Zach for your compliments. This sheet is a mere 8.5 x 11. It's just plain old cheap printer paper (and thank God I don't have to use that stuff anymore. This drawing may look nice but it was a pain in the neck to get it to look decent at all. It doesn't take well to graphite.)

Crocodile skulls (of which I've seen thousands) do NOT have lip holes. They have tiny little pinpricks scattered all over the skull, not just on the gumline. Not only do they not possess lips, but the entire head is wrapped in very TIGHT skin, which is anchored by all these scattered pinpricks in the skull.

Theropod lip holes are usually FAR deeper than those pinpricks, and they are ONLY found around the mouth, in distinct lines above the teeth. These anchored muscles, not little pinprick-sized sensory organs. The muscle scars are even present BELOW the holes.

Torvosaurus is unusual in that it lacks deep lip scars or holes, (though it does have some very LIGHT lip scarring if you look closely) so it probably had short lips and largely exposed teeth. But its skull does NOT indicate a lipless grin like a croc, nor does it have croc-like dimples.

It does have simples near the nose, these may have housed sensory organs as they were far above the jaw line. So overall I think my restoration with the short lizard-like lips is correct.

It's worth noting that Crocodiles are the only toothed reptiles that lack lips entirely. Lizards, snakes, Tuataras all have lips. Even early Crurotarsans had a bit of lip. Turtles don't count because they have beaks and no teeth, and are not even diapsids.

It's pointless trying to compare theropods to crocs as their skull structure and lifestyles are totally different. Crocs are aquatic ambush predators that will bite indiscriminately through weeds and logs if that's what it takes to reach an antelope. They need lipless jaws because lips would be a serious hindrance to their reactive, movement-based attack strategy.

Theropods were bipedal landlubbers who didn't have the protection of water or cryptic weeds, and whose gums were prone to drying out, as well as the fact that they were NOT indiscriminate ambush predators. They literally HUNTED which involved running and picking out a victim. They have far deeper and narrower skulls than any croc, indicating they were a lot more precise and picky in what they bit down on. And their eye structure is usually far more developed. These guys did not just chomp anything that moved. Tough lips would have also protected their mouths in fights, considering they had serrated teeth and not simple conical ones like crocs, that's a real obvious reason for having tough scaly lips.

As for Witmer.... I'll cover that a bit later.
Let's just say he jumps to conclusions based on the outward appearance of living animals without recognizing the obvious anatomical trends behind them. If you were to really go based on living animals, you would reach the conclusion that sauropods' fleshy nostrils were EXACTLY in the same spot where their bony nostrils are - there's rarely a discrepancy between the two in living OR extinct amniotes, except in elephants and whales, neither of which makes a good functional model for sauropods.

Show me a living LAND animal with no trunk, no nasal muscle scars, and yet has crazy nasal tubes outside the skull roof and exiting far beyond the bony nostrils, and I'll show you the death of functional biology as we know it.

Zach Armstrong said...

Alright, Michael, here is a front view of a Tyrannosaurus skull here: http://www.mccullagh.org/db9/10/t-rex-skull.jpg . (Paste it into your browser to see). Do these holes look all nice and neatly arranged? I don't think so. As you described croc holes, they are 'scattered all willy-nilly over the jaw bone.

ANd if you look at this picture here: http://michaelcovel.com/images/trex_155.JPG, you again see that these holes are not perfectly aligned in lizards, they kind of "jump" up-and-down near the front of the skull.

Now if you look at a gator skull, here: http://www.istockphoto.com/file_thumbview_approve/5223436/2/istockphoto_5223436-alligator-skull.jpg, you also see a "line of holes" on the bottom of the jaw, but that doesn't mean this individual had lips. These holes look pretty deep to me.

Now, I am NOT saying that theropods didn't have lips, it just seems to me that we need to be more careful before we make a final conclusion. What I AM saying is that there is enough differences between theropod 'holes' and lizard 'holes', and enough similarities between theropod and croc 'holes', that it is hard to say whether they had them or not.

Obviously differences are to be expected because theropods and lizards are NOT CLOSELY RELATED, so I do give some leeway there.

Nima, the truth is, all lipped tetrapods are either mammals or squamates (as for lissamphibians, I cannot find any reliable references that indicate they have lips, their skulls certainly don't have any 'holes' after a cursory check of google images, and I cannot find any mention in scholarly articles of amphibian lips). While the theropods' closest relatives (avians and crocodyliformes) have none. While this is not conclusive, it does seem to indicate liplessness for theropods. True, both of these groups have fairly specialized habits, but it should be of note that semi-aquatic lizards still have their lips and as far as I am aware, so do sea snakes (i.e., I can't think of a reason why an aquatic crurotarsan would have to lose their lips because of their aquatic habits). As for extinct crurotarsans having lips, this is subject to the same speculation as for theropods. I would even say it is less likely for them since their only descendants have no lips!

I also was not implying that theropods had sensory organs for the same purposes AS crocs, but simply these holes may have housed sensory organs LIKE crocodiles, but for different purposes. There is still much about theropod biology we do not understand (what an understatement!), so it is possible that these 'holes' have no living modern analogs.

I guess I am a skeptic on theropod lips, because even though I would like theropods to have lips, their isn't much strong evidence to indicate that they had lips. So while I would suggest that no one insists either way, illustrating theropods with or without lips is equally plausible in light of the current state of evidence.

As for sauropod noses, Witmer only argued that the nostrils came out down front. Some artists have made these to be like tubes, but as Darren Naish said on his take-down of sauropod trunks with comments on Witmer's sauropod noses, "it seems more likely that structures such as narial tubes were flush with other soft tissues of the head, and didn't 'stand out' like this."

So I don't think the narial tubes stood out like this (i.e., as Luis Rey (and others) has shown them), but this does not invalidate the osteological evidence that indicates the nostrils were down on the skull and close to the snout.

Michael O. Erickson said...

Thanks Zach, those pictures of T. rex skulls you provided just convinced me even more that theropods had lips.

"While the theropods' closest relatives (avians and crocodyliformes) have none."

Umm, maybe that's because avians have BEAKS.

"as for lissamphibians, I cannot find any reliable references that indicate they have lips, their skulls certainly don't have any 'holes' after a cursory check of google images, and I cannot find any mention in scholarly articles of amphibian lips"

Look at a bullfrog. Can you see it's teeth? No! It has thin rubbery "lip" skin covering them. Their skulls don't have holes because the amphibian lips are just skin, and do not have assosiated muscle like mammal, squamate, and theropod lips.

PLEASE copy-paste this into your browser:

http://www.agassiztrading.com/photos/photos-boneroom/croc-skull1-2.jpg

It doesn't take a rocket scientist to see that the croc holes look NOTHING like the theropod holes. The theropod holes are big, deep and ARE arranged in something of a row, albeit not a perfect one(why you think they don't is beyond me, as your pics clearly show it). Also note the teeth. The croc teeth have indentations near their bases so that the soft tissue can attach directly onto them, thus no lips. Theropod teeth are NOT like this. Also, theropods have realatively closely spaced teeth and a thin jaw rim (just like a lizard or snake), while crocs have widely spaced teeth and a thick rounded jaw rim. They're polar opposites! You are also ignoring the fact that there are prominant muscle scars assosiated with theropod holes, and there is nothing like this assosiated with croc holes.

I suspect Tracy Ford has implanted this junk in your brain, so it's not your fault at all.

"illustrating theropods with or without lips is equally plausible in light of the current state of evidence."

No, illustrating theropods without lips is a gross error. One of the worst errors a paleo-artist can make.

"their isn't much strong evidence to indicate that they had lips"

The evidence for theropod lips is so strong as to be almost conclusive.

Sometime I will have to publish a good paper on this issue and settle it once and for all, putting the anti-lips folks like Larry and Tracy in their place.

And please note that I am NOT angry or agressive, just frustrated is all. They're are so many things we don't know about theropod biology and anatomy and could debate about, and yet we still have to argue over something that is so well supported by evidence that it should be considered a common fact!

Zach Armstrong said...

Michael,

I don't think I ever said that theropods don't have deep holes lining their jaws. I DID however say that it appears some crocodile and alligator skulls have equally proportionally deep holes on their skulls.

Au contraire to your statement, the holes along the rims of the jaws of crocodiles DO look like theropod holes. In fact, if you look at this picture: http://www.dundee.ac.uk/museum/zoology/bagful/1515.jpg , they look just as proportionally deep as in theropods. In fact, this picture shows "scars" along the upper part of the upper jaw, just like the upper part of the maxilla in tyrannosaurs have kind of "scarred" markings. To me, the overall similarities between croc skulls and theropod skulls in these minute details is striking.

Also, as for anuran "lips", if they don't have any muscles (as you seem to admit), then they are NOT lips, by definition.

What is also interesting is that there are more of these holes on other parts higher up on the maxilla in Tyrannosaurus and other theropods (just look at the drawing of the skull of Raptorex in its new description--there are these holes high up on the maxilla and elsewhere as in crocodiles). In fact, there are many of these holes scattered about on the premaxilla in tyrannosaurs, and at the leading edged in the dentary as in the first picture of the Tyrannosaurus skull that I showed you. This is in the tradition of crocodile skulls, not lizard skulls.

You state that theropod teeth are more like lizard teeth, and while that may be the case for some genera (like Pelecanimimus and other small, omnivorous theropods), it is NOT the case for large theropods like Tyrannosaurus, Torvosaurus, Allosarus and Ceratosaurus. They had large teeth that were long and robust, far different from most lizard teeth.

I fail to see how the similarities in tooth spacing and the relative thickness of thiness of the jaw bone has anything to do with whether theropods have lips. In fact, depending on the species in question, such an assertion could be flat out wrong, as there is much variety in theropod jaw shapes. It also appears to me from looking at photos that theropods also had indentations at the bases of their teeth where skin could tightly adhere. I am soory, but I don not think the "scarring" on the maxilla has anything to do with muscle attachment, as similar "scarring" is also apparent on croc skulls, as I have already noted. It is also worth to note that lizards do NOT have such associated "scarring" on their skulls.

As for Tracy Ford, in the past I had a lengthy email discussion with him advocating FOR lipped theropods. My change of mind has little to do with his paper, which I though was slightly biased in that he chose a tyrannosaur specimen to work with that has an unusually pronounced overbite compared to other known specimens. He also failed to bring attention to that the "really long teeth" had slipped out of their sockets significantly and would not have been that long in vivo.

Also your comment about birds having beaks is noted and also slightly flippant in that I also mentioned crocodiles, not birds only. It may be that theropods had a keratinous rhampotheca covering on the edges of theirs jaws (interestingly, some authors propose that prosauropds had such a covering, and yet they also preserve these holes along their jaws that theropods have!). Where do you think birds' beaks came from???

Dogmatically stating that the case for lips is strong and therefore a fact does not make it one, Michael. It think your interpretation is ever so flimsy, IMHO. My main point was not to definitely say that theropods did not have lips, but to show that the evidence is not at all as conclusive as you may think.

And even though you say you aren't, you do seem a bit heated and aggressive over this topic, I might add.

Nima said...

Whoah Mike calm down! I know Zach makes some mistakes here but please lets keep this civil. I don't agree with Witmer or Tracy Ford any more than you do (and in fact I don't buy most of their theories at all, pinch of salt or no salt!) but don't be using words like "junk in your brain" on my blog. I know you're not angry but others might be... just remember that though I agree with your views, that's not a reason to be vicious with them. I won't delete your comment as it DOES have some useful info in it, but don't forget I'm the boss here.

Let's remember - bad science like Witmer's and Tracy Ford's results in BAD illustrations. The Paleo Kingdom will ALWAYS be the realm of good illustrations, not bad. Not perfect perhaps, but certainly good.

Now as for the theropod lips. There is AMPLE evidence that theropod lip holes are nothign like croc holes.

You don't even need and external link for this, just scroll WAY DOWN below to my Synapsids post... I have pics of diapsid skulls there too, so COMPARE the croc skull I posted with the Velociraptor skull that I posted. The raptor has a distinct row of holes ONLY on the lip area. The croc has pits and holes haphazardly scattered everywhere! THERE IS NO COMPARISON.

Now Zach, you argue that we know too little about the lips of theropods to even say if they HAD lips. Here's a thought - modern mammals with big lips don't even NEED lip holes, theropod lips are MOSTLY like those of a komodo dragon which DOES have lips!

Don't believe me, look at this:

http://www.azdrybones.com/images/Komodo-Dragon.jpg

you will see a single row of tiny lip holes. Now, these might not only anchor muscles. They may also be foramina for nerves and blood vessels to get to the lips. EITHER WAY, only reptiles with LIPS have a single row of holes like this. The raptor's lip hole look a LOT more like the Dragon's than the Croc's.

As for lizards and dinosaurs not being related... true, crocs have more in common with dinosaurs OVERALL than lizards do. But crocs are an offshoot of the crurotarsans, and MOST of the early pre-crocodylian crurotarsans had long limbs, a more erect stance, and - YOU GUESSED IT! Komodo dragon-like LIPS! They also had deep skulls that resembled a dino much more than a croc (except for or course, Phytosaurs).

Now we should ask WHY do dinosaur lips resemble lizard lips overall? Well, there's this thing called convergent evolution... where unrelated animals develop similar features. In fact, crocs converged on Phytosaurs, and dinosaurs may not have even HAD to converge on lizards - their Archosaur ancestors, the basal ornithodires, seem to have had EXACTLY the same lizard-lip configuration as the early land-living crurotarsans! In other words, lips were an ANCESTRAL REPTILIAN TRAIT! Dinosaurs INHERITED it anyway, they had no need to "converge" on lizards. Both the ancestral Ornithodirans AND Crurotarsans had lips, ONLY the phytosaurs, crocs, and a few other crurotarsan groups lost their lips altogether MILLIONS OF YEARS LATER.

And surprise surprise, these lipless forms are ALL aquatic ambush predators with relatively undeveloped brains that will bite at almost anything that moves. That's why they couldn't have lips getting in the way, unlike theropods which had more advanced brains and vision, and were ACTIVE HUNTERS who actually had to chase down and pick out what to bite and attack. Lips would certainly have served them well on land, as they do with all land predators today.

Once again, the comparison with crocs has FAILED. Don't take this personally Zach, but it's a pretty weak argument.

Nima said...

As for Witmer... again.... regardless of whether his mistakes inspire weird exposed tube-noses like those of Luis Rey, or more "covered up tubes", the fact is there is still NO osteological evidence for these tubes. On macronarian skulls, you have a bunch of pits but no actual trace of TUBES or passages being anchored there. The pits could just as easily have housed pheromone glands, sensory organs, or just anchored some very tough skin. They do NOT support Witmer's theory beyond reasonable doubt in ANY way.

With diplodocid skulls, the case is EVEN WORSE. There are no pits or scars of any sort whatsoever on the bones of the snout roof. There's no proof that ANYTHING other than a thin layer of skin covered the bones.

And again, Witmer's main premise is flawed in the first place. He argues that based on dissections of living animals, sauropod nostrils must have exited at the tip of the snout. Unfortunately, none of these animals have a nasal structure even remotely like sauropods. Larry Witmer's sauropods would be the only creatures in history to have nostrils on the forehead with long extra-cranial tubes coming down to the nose that DO NOT end in a trunk.

If you really want to learn from dissections the RIGHT way, remember this - non-proboscidean land animals, from reptiles to mammals, ALWAYS have fleshy nostrils on top of, or very close to, their bony nostrils. A trunk-less animal with nasal tubes stretching far beyond the bony nostrils DOES NOT EXIST.

In addition, Witmer seems to ignore the fact that there must have been an evolutionary reason for the nostrils to shift so high. All sauropods exhibit this shift across epochs. And indeed it makes sense that while poking their heads deep into the forest canopies, they needed to protect the nostrils from injury by a lot of the prickly mesozoic conifer needles. So putting them on top of the head is a lot more efficient than on the tip of the snout near the mouth - after all, that big mouth is poking straight into the rather rough foliage. Now THAT is real, efficient evolution.

Now as for the flaw in Witmer's dissection lab logic...if you follow the example of every modern animal whose skull can even be COMPARED to sauropods, you reach the conclusion that the fleshy nostrils also were probably MEANT to be high up NEAR the bony ones. Only then is there ANY consistent pattern between the faces of sauropods and all other land vertebrates. If you don't have a trunk, chances are you don't have a lot of distance between your bony nostrils and your fleshy ones. What's more, any fleshy nasal tubes like in mammals, are parallel with nasal passages in the skull. Whereas the bony nasal passages of sauropods (especially diplodocids) are nearly PERPENDICULAR to Witmer's proposed external canals. Such a pattern does not exist anywhere on land outside the elephants (and in any case, for them it ACTUALLY serves a utilitarian purpose)

So basically in a nutshell, Witmer's "osteological evidence" doesn't support his argument at all (and is in some cases totally absent), and his logic based on dissections is also flawed - all those rhinos and giraffes and lizards he dissected have very SHORT fleshy nasal tubes if any at all, their fleshy nostrils are tight on top of the bony ones. He strains for the ends without appreciating the need for valid MEANS (which in this case are very short fleshy ones).

Witmer's theory = rampant speculation masquerading as good science = defeating the purpose of the high nostrils altogether.
Now I'm not in any way bashing Witmer himself, he's done a lot of good work with dinosaur skulls, brains, and sinuses, but on this particular point he's woefully gone awry and caused a lot of needless confusion.

Nima said...

BTW, Zach, here is and even BETTER pic of a Komodo Dragon skull:

http://www.wildsidephotography.ca/Flores/23271m.jpg

It's got the EXACT same sort of lip holes as most theropods.

And as proof, here's T. rex "Stan". It's got SINGLE lines of lip holes only on the lip ares! Just like the dragon:

http://michaelcovel.com/images/trex_155.JPG

And here's Sinraptor, just to show that lips were NOT only a Tyrannosaur thing:

http://www.palaeos.com/Vertebrates/Units/340Theropoda/Images/Sinraptoridae1.gif

Please paste these URLs and look at ALL of these pics before attempting to weaken the credibility of theropod lips. It's true not ALL of them had honkin' big lips, but they all seem to have lips of SOME SORT or another.

NOW here is a CROCODILE skull:

http://creative-commons-photo.com/getitext.php?i=Animals/Crocodile-skull.jpg

There is NO distinct, SINGLE ROW of lip holes, instead there are pits and holes scattered ALL OVER THE DENTARY and in fact all over the skull. Even the pits near the gumline DO NOT sort out into anything like a neat even row.

There is SOME vague resemblance but the croc-lips argument is FAR WEAKER than you make it seem. Let's remember that based on early diapsid skulls following the Komodo dragon-like pattern of a single row of lip holes, it's almost certain it's an ancestral reptilian trait.

Even crurotarsans had the komodo-style lip holes!

Postosuchus:

http://www.palaeos.com/Vertebrates/Units/270Archosauromorpha/Images/PostosuchusSkull.gif

Saurosuchus (at least it has a straight row on the lower jaw! and no croc-like facial pits):

http://science.naturkundemuseum-bw.de/files/Fig-18.jpg

Stagonolepis:

http://www.palaeos.com/Vertebrates/Units/270Archosauromorpha/Images/Stagonolepis_skull.gif


AAAAAND.... even DISTANTLY related reptiles like the TUATARA have lips and lip holes!

http://upload.wikimedia.org/wikipedia/commons/2/23/Tuatara_skull_labelled.png

And even slow worms have them... although their lips are small, they are NOT absent as in crocodiles! Here is a skull with some of the lip flesh still attached:

http://scienceblogs.com/tetrapodzoology/Langham_slow_worm_Shoreham_by_Sea.JPG

Again we see a SINGLE row of lip holes on each jaw (you can just make out the front of the mandibular row).

So crocs are really the odd man out, they lost the lips and the single row got replaces by pits all over the place. but practically ALL OTHER REPTILES retained lips and lip holes.

Even cynodonts retained them and passed them on to mammals:

http://www.ctlab.geo.utexas.edu/imagefolio/paleo/mammals/stills/EthrinW.gif

You also even find a few traces of them in giant Salamanders:

http://www.boneroom.com/casts/images_bc/herp_giantsalamander.jpg

AND Newts:

http://www.preemptivekarma.com/archives/Newt-2004-clipped.jpg

So overall lips are quite common LOL!

Michael O. Erickson said...

"Whoah Mike calm down! I know Zach makes some mistakes here but please lets keep this civil. I don't agree with Witmer or Tracy Ford any more than you do (and in fact I don't buy most of their theories at all, pinch of salt or no salt!) but don't be using words like 'junk in your brain' on my blog."

Well, I have some explaining to do there. Ya see, that was actually a "rough draft" comment - one I was toying with but was NOT NOT NOT going to post. Unfortuanately, I hit "post comment" my mistake and it ended up being published. I never intended for it to be made public. It was a mistake on my part. Sorry.

Michael O. Erickson said...

Again, that comment was NEVER actually intended to be published, and I apologize for it.

Nima said...

Lol cool man I understand. Though you could always type them in notepad or MS word before pasting them in.... that would avoid any embarrassing accidents. In fact I may do the same since I 'm sick of dealing with so many typos that I missed...

though it might be better to apologize to Zach, not me. In any case there's plenty of evidence I just posted the links to above that proves that lips are an ancestral reptilian (or maybe even an ancestral amniotic) characteristic shared by many groups, including dinosaurs AND some protomammals as well.

While I don't agree with Zach, I concede that SOME dinosaurs had less extensive lips than others. T. rex and Giganotosaurus both looks like they had some major lips, but Torvosaurus and a number of others had far less lip and likely the teeth were quite exposed as in my restoration. The lipless crocodile configuration is not like any dinosaur yet found with the POSSIBLE exception of the Spinosauridae (including Baryonyx). In THEIR case I would not rule out the loss of lips (again this would be a case of convergent evolution since Spinosaurs were fish eaters and may have even swum in rivers and lakes in search of food - where feeding frenzies with crocs could just get BRUTAL and lips were more of a curse than a blessing).

IMO, Spinosaurs are the only dinosaur group that could possibly have lacked lips entirely.

Michael O. Erickson said...

Thanks, Nima. And sorry Zach :)

"While I don't agree with Zach, I concede that SOME dinosaurs had less extensive lips than others. T. rex and Giganotosaurus both looks like they had some major lips, but Torvosaurus and a number of others had far less lip and likely the teeth were quite exposed as in my restoration."

Agreed.

"IMO, Spinosaurs are the only dinosaur group that could possibly have lacked lips entirely."

Yikes! Lipped hadrosaurs? No, LOL, I know what you meant. In fact Greg Paul said as much in his paper, "The Totally Extreme Lifestyles and Habits of the Super-Awesome Gigantic Tyrannosaurid Superpredators of the Late Cretaceous of Asia and North America"... or something like that. It was in the recent Tyrant King volume from Jim Farlow's Life of the Past series. Greg said and I quote:

"The crocodilian-like dentition of spinosaurs suggests they were lipless, at least along the anterior tooth row..."

Nima said...

Lol yeah, yikes indeed! Lipped hadrosaurs (or ANY of the predentata having lips over the beak) is pretty wacky and not realistic.

But in lieu of lips they most certainly had cheeks.... which is also very UN-crocodylian.

Come to think of it, in the Disney movie "Dinosaur", the Iguanodons had lips over their beaks! When will those hacks stop trying to make animals and their facial expressions look more human?! Not to mention injecting their Carnotauruses with ridiculous amounts of growth hormone, turning Brachiosaurus into a pathetic whiny weakling, and giving the old male Iguanodons an oddly ceratosaurian nasal bump!

As for Spinosaurs, I think Greg Paul is right on the money! The front of the mouth is very croc-like and probably had tightly stretched skin covering it, but interestingly, Suchiomimus has a very distinct, single lip-like row of holes further back on its lower jaw... so even these guys may not have been FULLY lipless. One thing's for sure though, with their tight-skinned croc-like mouths, they could easily have competed with some types of crocs for food, both as fish eaters and frenzy-feeding scavengers.

Michael O. Erickson said...

That Disney Dinosaur movie was crap. I did like the dinosaur segment of the original "Fantasia", though - although it was very inaccurate!

"As for Spinosaurs, I think Greg Paul is right on the money! The front of the mouth is very croc-like and probably had tightly stretched skin covering it, but interestingly, Suchiomimus has a very distinct, single lip-like row of holes further back on its lower jaw... so even these guys may not have been FULLY lipless."

Hey, I noticed that as well. About a year or so back, the traveling Nigersaurus exhibit made it to my local museum (the Sam Noble Oklahoma Museum of Natural History), and a cast of the Suchomimus skeleton was there. I immediately examined the skull, and the tip of the snout was, as you said, very croc-like. But before I wrote down "no spinosaur lips" in my mental notebook and moved on, I noticed the lower jaw. I concluded in my head that spinosaurids (or at least Suchomimus) had reduced lips along the sides of the jaws, but none at all at the tips. I thought I had a new, novel theory until I read Greg Paul's article and learned that he had thought the same thing!

Nima said...

Dude you must be psychic! I'd bet that 90% of the theories I came up with had already been proposed by Greg Paul a decade earlier while trimming his beard! Better watch out, he's becoming the Chuck Norris of the Paleo World...I thought exactly the same thing about the spinosaurs - their lips transition into a croc snout... I also noticed that even though spinosaurs have a crocodile-like skull, it's still WAY narrower and less flattened than that of most crocodiles. I have a hunch that deeper skulls and bigger lips go hand in hand to some extent.

So dinosaurs like Giganotosaurus with its narrow, pointed skull would have pretty big lips, since these types of skulls tend to have big lip holes in a well-defined row.... except for the odd skull of Torvosaurus, which doesn't follow this pattern at all!

The oversized teeth on that guy just freak me out, I'd swear it was a Tyrannosaur if it didn't live in the Jurassic and have 3 fingers... I'd guess something like that was built to kill something REALLY big and dangerous... like a Dacentrurus (now the small lips make sense when facing all those brutal spikes that can tear through big soft lips!), but maybe even Dinheirosaurus as well... If these guys hunted in big packs, who knows, even Lusotitan might have been on the menu once in a while!

Michael O. Erickson said...

"I also noticed that even though spinosaurs have a crocodile-like skull, it's still WAY narrower and less flattened than that of most crocodiles."

Certainly. I have often wondered what kind of freaking tongues spinosaurs would have had. I mean, the lower jaw is SO narrow down most of its length that the tongue would have to have been retarded skinny... Either that or the tongue was fat and confined to the back of the lower jaw, where it widens considerably.

About the lifestyle of spinosaurs - in the Edmarka rex descriptive paper, Bob Bakker and company explain that spinosaurs may have been "a radiation of marine predators akin to early Tertiary seals and toothed whales." Bakker himself has also elaborated on this (though not in print), saying that spinosaurs may have spent most of their time swimming in the ocean like half-baked theropod versions of saltwater crocodiles. He also claims that the heavy tail may have been a sculling organ. Although this sounds kinda... weird, I feel it may actually be more accurate that the assumption that even though they were fish eaters, they still spent most of their time on dry land just because they're theropods and that's what they SHOULD do. The Suchomimus cast I saw at the SNOMNH really DID look sorta short-legged and heavy-tailed, kinda made me wonder. Your thoughts?

Zach Armstrong said...

Alright Nima and Michael, both of you make good points, but your logic is slightly flawed. Nima, in your case you assume that the 'holes', the foramina, have something to do with lips. The truth is, you do not know that, and the evidence does not really support that. A simple stacking of the cards with numerical bias, i.e., "all extant lipped reptiles that have these lined foramina have lips, therefore the foramina have something to do with lips" is not a sound logical argument. Anybody with a basic knowledge of statistic knows that correlation does not imply causation. Neither you, Nima, or Michael, have shown these foramina have something to do with lips. They may in fact be a red-herring. I never denied that other crurotarsans had these foramina (and I did examine all those nice pictures whose URL you gave me.. thanks!), what I DID say was that I do not think they had lips. In fact, the fact that frogs, which Michael says have lips, do not have these foramina, indicates that foramina (while usually present with lips) may in fact have little to do with the actual presence of lips. What we have is a sample bias.

Several things neither of you have addressed is why many theropods (including tyrannosaurs) have extra 'holes' on other parts of their maxilla, premaxilla and skull that obviously had nothinhg to do with lips. These are positioned in a manner similar to crocodiles. (See any skull reconstructions of theropods by Greg Paul in Dinosaurs of the Air, Predatory Dinosaurs of the World, or the Scientific American Book of Dinosaurs to see what I am talking about. These holes are also evident in the new description of Raptorex, if you have access to it, and on some images of T. rex skulls)

And that is the main thrust of my argument, to prove either way whether these lined-up foramina have anything to do with lips you must prove (1) that the foramina in crocs differ significantly in morphology that they are not homologous or analogous to theropod foramina, (2) shoe that the foramina in lizards are functionally/morphologically homologous or analogous to theropod foramina, and (3) show that the extra foramina that dot theropod skulls in various places are different than the lined-up holes along the jaw line. This will take a in-depth technical analysis. Until then, one should refrain in the name of logic from being too dogmatic about this lipped/lipless discussion.

Zach Armstrong said...

(Part II of my comment...too many characters)

Also, you must explain the difference in the jaw mechanics between theropods and lizards. While I have grave doubts about some aspects of Tracy Ford's paper, there is one thing it does well: show that theropod jaws and lizard jaw are mechanically very different. The main important thing is that the upper and lower parts of the jaw in lizards line up pretty much on top of one another when they shut. In theropods, it is very much different. In fact, fossil evidence shows that the teeth in the lower jaw rested in grooves on the palate of the upper jaw, i.e., the teeth touch the upper palate. This means theropods had a very deep bite, much different than most lizards, and also posing a problem for the lip hypothesis.

The problem is that the outer edge of the lips on the lower jaw would have been on the INSIDE of the upper jaw and teeth in theropods. This means the lower lips (if they indeed existed) would NOT cover the upper teeth. This means that even if theropods had lips, their teeth would still show significantly, and thus still make reconstructions of closed-mouth theropods showing no teeth inaccurate.

In constrast, lizard jaws line up more or less right on, definitely not having the deep bite that theropods have. Because of this, their lips can rest on the outside of the jaws nicely, without the teeth getting in the way.

It is this mechanical evidence that give me the gravest doubt in the "lips hypothesis".

Zach Armstrong said...

(Part III of my comment)

And lastly, I must strongly remind you that I never said that theropods did not have lips. What I AM saying is that we should be cautious and not get too dogmatic on the matter.

And as for that croc skull image that you cited up there Nima, I see a nice little row of foramina lining the upper jaw. True, they may not be as "dark" and "deep" looking as in theropods, but you have not given any reasonable proof that these foramina HAD to be that deep to support lips.

Another relevant point, all the TECNICAL literature to date has favoured lipless theropods. True, some such as Bakker and Paul have favoured lips, but they have not published anything in a peer-reviewed publication. Nor have their arguments been all that detailed, frankly.

Also, you failed to address the point that sea snakes still retain their lips, even though they are aquatic. Furthermore, lips would be MORE useful for an aquatic animal in that they could provide suction for getting small prey, which makes me also wonder why crocs would have lost such a useful tool (even the small ones such as modern gharials and dwarf caiman), these points, too must be addressed. Such usefulness is absent in theropods.Non-beaked theropods were not foragers, and so lips would have no real usefulness in obtaining food like they do in small insectivorous lizards, and herbivorous mammmals.

Theropods were homeothermic, lizards are poikilothermic, and this also has a say in the lips matter. Lizards do not have the energy to spend that theropods do. Even your favorite example of comparison, the komodo dragon, lives a very different lifestyle than any theropod. In fact, it is now known to be truly venemous. One bite, and the venom slows down the prey and the komodo moves in for the kill. The lips provide a useful storage of the venom as it oozes. Theropods, on the other hand, had no such need as they were active "slashers" that repeatedly attacked their victims drawing more blood and weakening them in most recent analyses. Lips also serve a use in insectvorous lizards in heloping tame small, squirmy prey. Large theropods had no such need when they were dealing with multi-ton ornithopods, sauropods, and ceratopsians. Lips are just not needed.

I would be happy to be proved incorrect in my leanings, but it is going to have to take some really GOOD technical analysis to prove to me either way.

Until then the jury is out, in my book.

And I agree with you guys on the spinosaurs.

And that about ends by tangential comment.

(I really should just start a blog, then I could show you nice pretty figures of what I mean, instead of my poor abstract descriptions of the relevant anatomy and mechanics...*sigh*)

Zach Armstrong said...

Oh, and as for Witmer's sauropod noses, I really do not have a lot of extra time to go into that. What I will say however (and which is a shameless ad hominem argument and logical fallacy) is that Darren Naish agrees with Witmer's conclusion on noses, here, so it MUST be correct ;). Well, not necessarily, but he gives some brief, but IMO, strong, arguments in support of Witmer's hypothesis. Including EPB, the actual fossil evidence, etc. While I do not agree with Witmer on his view on cheeks and such, I do agree with him here.

Zach Armstrong said...

Oh and Michael, I really wasn't offended by your comment. Just though it was over-the-top. All is forgiven (although, there was really nothing to forgive for: we're all human...) :)

Michael O. Erickson said...

Thanks, Zach. Much of your comments are too detailed for me to get into right this moment, but I do have a couple thigs to say.

"Another relevant point, all the TECNICAL literature to date has favoured lipless theropods. True, some such as Bakker and Paul have favoured lips, but they have not published anything in a peer-reviewed publication. Nor have their arguments been all that detailed, frankly."

I don't want to be a wise guy, but this is incorrect. Greg Paul has, indeed, published a detailed summary of his lip arguments in a perfectly good peer-reveiwed publication - in this case, it's Tyrannosaurus rex: The Tyrant King, edited by Ken Carpenter and Peter Larson. Just for giggles, here is the revelant peice of text (typed by hand, from chapter 18):

"In most avepods, the rims of the bones immediately lateral to the tooth rows were sharp edged, and the teeth were closely spaced. This arrangement is more similar to lip-bearing amphibians and lepidosaurs than to crocodilians, which are unusual in lacking tooth coverings. In crocodilians, the rims of the jaw margin tend to be rounded, and most teeth are set in widely spaced sockets. In most theropods, the maxillary teeth were modest in size, and the lateral row of foramina on the dentary is set immediately below the tooth row. In ceratosaurs and tyrannosaurids, the teeth were longer and the lateral row of foramina set lower on the dentary. The relationship between maxillary tooth legnth and dentary foramina position is not explicable if lips were absent, but is loical if the mandibular lip pocket was deeper in ceratosaurs and tyrannosaurids in order to accommodate their longer teeth. The crocodilian-like dentition of spinosaurs suggests they were lipless, at least along the anterior tooth row."

Phew.

Zach Armstrong said...

Yes, Michael, but it was not a technical (that's the correct spelling, sorry for the typo in my earlier comment) treatment of the evidence. This is basically just some fluff (concerning the lips, not the rest of the article). As I mentioned afore, the foramina may have nothing to do with lips! And as I described above, Paul here does not address any of the serious mechanical issues that have to deal with the practicality of lips that I mentioned above. He does not go into any detailed review of the structure or nature of foramina in extant taxa and whether they have anything to do with lips being present (in fact, there are some extant taxa that lack the foramina that have lips, such as many Anurans!). Until this relationship is proved, any argument based on this is, pardon the expression, complete phooey!

And frankly, I think Paul has missed the ball on the relationship between tooth length and the foramina. It is true that ceratosaurs and tyrannosaurs have their foramina lower on the dentary. BUT, and here is the caveat, if you close the jaws of either group, the teeth extend beyond these foramina. If the lips started here, as you and Paul hint at, then the teeth would have pierced right through where the lips attached to the dentary! (This has to do with differing jaw mechanics between lizards and theropods that I mentioned above) This seems like a big problem to me. If you have found a way to get around that problem, I would gladly be enlightened.

One more problem in Paul's assessment: he does not state why tooth placement and arrangement is relevant to whether theropods had lips or not. It is true the amount of teeth and how tightly packed they are is similar to lizards. What he has NOT proved is that this has anything to do causally or mechanically with the presence of lips or not, and this is where I have many grave doubts about the argument.

A agree with Paul that spinosaurs were likely lipless, but not for his mentioned reason: the croc-like spacing of teeth on the dentary has nothing, in my opinion, to do with the presence or absence of lips. I simply agree to the extent that I think that it is more likely that all theropods lacked lips.

Amen to your "Phew".

Nima said...

Zach, you're right about one thing... you really SHOULD start a blog. Because I do want to see what you mean in pictures....

I think that was indeed a tangential set of comments.... in fact I don't think it was too terribly relevant to theropod lips, but it did give some insight.

My main argument AGAINST lipless theropods really is not so much based on lizards but on comparisons with a wide array of animals.

My point was that lips are an ANCESTRAL AMNIOTE TRAIT, most reptiles, frogs and even Newt have them...

Crocodiles are the EXCEPTION not the rule. This is the main point I'm making. Even reptiles as primitive and un-dinosaurian as the Tuatara have lips. So in my mind the ONLY way that theropods could have been lipless is if they evolved from an ancestor that had lips, but then lost them for some reason later on.

There are some glaring flaws in your argument.

FIRST you cite crocodiles in your support. Even after I posted links to several dinsaurs, crurotarsans, lizards, and a croc, you still claim the dinosaurs follow the croc pattern... that is simply NOT the case. ONLY CROCS follow the croc pattern. Even the "foramina" on their lips look "stretched" in a certain pattern which indicates tightly bound skin. Every theropod I posted has a pattern much more like the Komodo Dragon. If you can not see this I am truly sorry.

SECOND, you claim that Komodo Dragons are a bad model for theropods because their lifestyle involves using venom. FALSE AGAIN. Komodo Dragons do NOT have venom of ANY sort, nor are their teeth hollow like venomous snakes to allow venom to pass through. In face Komodo Dragons kill their prey with BACTERIA that fester in their mouths, not with venom. Whether some theropods also had a festering bite is entirely up in the air, but it is TOTALLY IRRELEVANT to their lips or their tooth structure, because other varanid lizards that do NOT have a septic bacterial bite have the same sort of lip and tooth structures.

THIRD, you claim that the Dragons are polikothermic (cold-blooded) and therefore are a bad model for homeothermic (warm-blooded) theropods (yeah I know I'm probably oversimplifying the terms... oh well). Actually, lips have NOTHING to do with being warm-blooded or cold-blooded. JUST ASK ANY CARNIVOROUS MAMMAL!

Not to be mean, but seriously have you ever seen a lipless lion or wolf? So does having lips make them cold-blooded? Lips do not indicate a creature's metabolism either way. Just like crocs are not warm-blooded....

And by the way... if being polikothermic is enough to make lipped lizards a bad model for dinosaurs, then why do you consider cold-blooded crocs to be a good model?

FOURTH, you cite anurans having lips but lacking foramina as proof against lipped theropods. WHY do you have to go back as far as anurans to find an argument. If lizards are bad proof in favor of foramina supporting lips, do you think that frogs are any batter as an argument against it? They are FAR more primitive and distant from dinosaurs! Logic please?

Furthermore, the frog example actually support MY argument, not yours. The fact the frogs can have lips without foramina, and the fact that every reptile with foramina has them EXCEPT crocs, makes it OBVIOUS that lips are very widespread in the animal kigdom, and that both theropods with deep foramina and those without (like Torvosaurus) could EASILY have had lips. And you have NO PROOF that they didn't have them.

Nima said...

FIFTH, you claim that sea snakes having lips invalidates my stance about crocs and their aquatic lifestyle. WAIT A MINUTE! You blasted me for using Komodo Dragons as proof for my argument by falsely claiming they rely on VENOM, yet here you are relying on VENOMOUS SEA SNAKES to support your line of reasoning! Sea snakes have NO COMPARISON to crocs here.

My point WAS that crocs lack lips because they are bulky ambush predators that lie in wait for prey and then lash out at ANYTHING that moves. Their vision is based heavily on movement (which Jurassic Park also falsely assumed about T.rex). Crocs attack their prey totally different from a sea snake. They thrash, twist, and bite even through wood and solid objects to get to their prey, they bite each other's mouths which is easily done due to their flat heads and shallow jaws. They go through a LOT more brawling to kill prey than a fragile sea snake which injects venom then lets go and waits for the prey to drop dead. Since it doesn't "crush the rocks to be there" (to quote Genghis Khan) it does not need to do away with lips, which in any case are a family characteristic of all snakes.

Your dainty sea snake comparison to a brawling, mud splashing MURKY RIVER DWELLING croc that will instinctively bite through even logs to kill a moving animal, is easily the weakest and most indirect argument I've seen anyone make against theropod lips. Their lifestyles are not even remotely similar.

Essentially, here's your problem:

*you rely entirely on crocs as the only "positive" evidence for lipless theropods even though this is a derived lifestyle trait found ONLY in crocs today when there are plenty of terrestrial lipped creatures whose foramina are far more theropod-like than crocs.

*you then cite a bunch of "negative evidence" that proves NOTHING about your argument conclusively - like lipped anurans without foramina, sea snakes with lips, and the claim that foramina have no connection to lips (they actually DO in nearly every amniote that has foramina apart from crocs!) You fail to distinguish what sort of foramina and pits indicate tightly stretched skin and what sort are associated with flexible skin with muscles... the proof is in living animals, what more need I say? Your tactic is very much like a very inexperienced lawyer, to sow doubt by using confusion, unrelated facts, and using reverse logic... that does not hold up in true science.

*you ignore convergent evolution and all it entails...

*you seem to ignore the fact that lips are an ancestral reptilian/amniote characteristic, and even though some amphibians developed it too you apparently can't make the connection that LIPS ARE VERY OLD and crocs are the only group aside from phytosaurs that lost them completely.

*you throw all sorts of reasons why komodo dragon lips are a bad model for crocs (polikothermic, "venom", etc.) when the same and even worse problems can be attributed to your examples of crocs and comparing them with sea snakes...

Nima said...

(...continued from last comment...)

* You have only crocodylia in your support whereas I have pretty much ALL THE REST OF DIAPSIDA!!!

*you fail to find any DEEP JAWED creature with no lips on land.... and all theropods, even spinosaurs, had jaws deeper than they are wide.

*you imply an aquatic lipless lifestyle to terrestrial predators whose gums were likely moistened and could dry out without lips. Crocs don't have this system, but most other reptile and EVERY LAND MAMMAL does!

*you claim that aquatic animals like sea snakes can have lips too... WHAT ON EARTH does this prove? So aquatic snakes have lips... well, ALL snakes have lips! All diapsid reptiles HAD lips to begin with. Even the crurotarsan ancestor of crocs had foramina for LIPS like those of varanid lizards... you don't have to be related to lizards to have this, it's a trait of ALL ancestral amniotes!

*you fail to show ANY convergency of evolution between crocodiles and the majority of theropods, which is the only hope left for your theory. Indeed, there is a DIVERGENCY between crocs and ALL OTHER ARCHOSAURS...... even their pseudosuchian ancestors had a lifestyle and posture closer to dinosaurs than crocs themselves are.

*you can not produce a SINGLE example of a creature with dinosaur-like foramina and a terrestrial lifestyle that does NOT have lips. Crocs, whose pits are very different, are your SOLE EXAMPLE in the animal kingdom, and a very lousy one at that.

Michael O. Erickson said...

WOW! That's one seriously good rebuttal Nima, far better than I could have done. However, you do make one glaring error:

"Komodo Dragons do NOT have venom of ANY sort, nor are their teeth hollow like venomous snakes to allow venom to pass through. In face Komodo Dragons kill their prey with BACTERIA that fester in their mouths, not with venom."

This has recently been disproven. Read all about it (LOL) here (as usual, copy paste it into your browser):

http://scienceblogs.com/notrocketscience/2009/05/venomous_komodo_dragons_kill_prey_with_wound-and-poison_tact.php

But it is still TOTALLY IRRELEVANT to the lips issue, because lips are, as Nima is saying, a PRIMITIVE AMNOITE FEATURE, and other lizards that do NOT have venom have THE SAME LIP AND TOOTH STRUCTURES!

Also interesting is this quote from Bryan Fry himself: "What we have seen, however, are sustained frenzied attacks persisting for several minutes until the large prey item is dead from blood loss." Sounds similar to how a pack of large allosaurs would bring down a sauropod or whatever!

As an unrelated note, also out the window is an old argument against venomous theropods - "Something that large wouldn't need venom."

By the way, this is one hot little debate we have here!

Michael O. Erickson said...

And Nima, for some, er... INTERESTING reading, copy-paste this puppy into your browser...

http://jeb.biologists.org/cgi/reprint/204/22/3917

...and click "manual download".

(Note: completely unrelated to the lips discussion)

Nima said...

Wow I never knew Komodo Dragons had venom... so I take back THAT part of my rebuttal, however not all monitor lizards have venom (though a few do). The diagram is a bit ambiguous though - it says nothing about what role the foramina played, if any, in delivering the venom.

However this does not invalidate the presence of lips on the foramina of theropods. Indeed, the fact still stands that lips are an ancestral basal trait of ALL amniotes, most of which (particularly the tall-skulled ones) still possess them.

I also read the other paper, that is some very interesting stuff... I don't know if that is a veiled jab at my turning Torvosaurs but either way I don't mind, it's a very interesting article. Probably big theropods could not turn as fast as little ones like most raptors.

Michael O. Erickson said...

"The diagram is a bit ambiguous though - it says nothing about what role the foramina played, if any, in delivering the venom."

The foramina play NO role in venom delivery whatsoever, actually. Absolutely none.

And no, I don't think the paper is a jab at your turning torvosaur, especially because there is an awful lot of confusion going on, with those Dacentrurus tails flying around and whatnot. I donubt the theropods would be behaving TOO normally in that situation.

BTW, what DO you make of the allosaur Carrier and crew illustrated in a "jack-knife posture"? It kinda reminds me of how basilisk lizards run, really surprising. They claim that theropods ran like that most of the time, and that they rarely assumed the horizontal posture we're used to.

"...like most raptors."

I thought you hated Jurassic Park! :)

Marica said...

Hi,

I've just stumbled across your blog and wanted to tell you how awesome your drawings are! First time I came across Paleo Art too.

I draw and paint myself but I never drew dinosaurs. You put in so much detail in your work. Very professional and elaborate.

I wish you all the very best with your studies. If you put as much dedication in them as you do in your art, I'm sure you will do great.

Cheers,

Marica

Nima said...

Hey thanks Marica! I learned to draw dinosaurs largely by trial and error, without any teachers or classes (it's not a subject most art teachers have any experience in - and figuring out which professional paleo-artists actually knew their stuff and were worth studying was also trial and error!)

I've been working at it since 1994, so I appreciate your comments about my paleo-art a lot.

I'm curious, since you said you never drew dinosaurs... what kind of things to you draw and paint?


And Mike, I don't really think much of the "basilisk lizard" posture as applied to Allosaurs. I don't think this posture was in any way realistic for bigger predators, especially since the tails of MOST large theropods can't bend into a jackknife position. With their stiff spines, such an odd position is very unlikely.

Also I don't think the paper was a jab at my work; lol the authors obviously don't know me. I meant to ask, jokingly, if you were sending me the link to make a playful jab yourself, at my Torvosaurs who didn't seem to be following the conclusions of the paper (which I don't necessarily agree with 100% anyway). And you're right, the Torvosaurs are panicked that one of their own just got slashed open. But they are already on the attack and can not turn away easily... though one of them may indeed be trying.

As for Jurassic Park.... I don't really get the reference there, but yeah, I do use the term "raptors" in lieu of "Dromaeosaurs" quite often. It's just easier and everyone knows what I mean. I just didn't like how the raptors (in this case Velociraptors) turned out in JP (too big, no feathers, a head more like Deinonychus, etc.), but I'm fine with just using the term "raptor" without any potential Spielbergian connotations.

Nima said...

Oops, correction: I meant "large theropods in general" rather than just "Allosaurs".

The authors of that paper DID use Allosaurus as an example, though the paper prefers that posture for large theropods overall, not only Allosaurs. And of course I am well aware that Torvosaurus is not an Allosaur. But since both of them were tetanurans I expect Torvosaurs and Allosaurs had a similar running posture... and I still think it was a horizontal one, NOT a crazy jackknife/basilisk lizard thingy.

However, big theropods probably DID tilt upwards when they were NOT running, to survey their surroundings or stand lookout to spot bigger predators coming to steal their kills while their friends were taking their turn eating.

Michael O. Erickson said...

Actually, I WAS joking around by referring you to that paper with the basilisk lizard allosaur. I was kidding the whole time actually, including in explaining how the torvosaurs in your picture are not behaving "normally" (i. e. they're not in the goofy jacknife posture) do to the panicked situation. I should have made it more obvious.

As for Jurassic Park, the reference was just because I usually hear fans of the film referring to dromaeosaurs as "raptors", whereas those who disliked the movie often rufuse to call them that. But anyway, I use "raptor" myself a lot.

"I just didn't like how the raptors (in this case Velociraptors) turned out in JP (too big, no feathers, a head more like Deinonychus, etc.)"

There's actually an interesting story behind that. It's all because the raptors in Jurassic Park really ARE intended to be Deinonychus. They got labelled Velociraptors because Speilberg used Greg Paul's "Predatory Dinosaurs of the World" as his primary reference for dinosaur information, and in the book Greg considered Deinonychus to be simply an overgrown American species of Velociraptor, V. antirropus.

Zachary said...

Hey, Nima. Love the picture overall, but I'm in London, having just left SVP, so I've got some "new" information for you.

1) I saw the Dacentrurus type at the London Museum of Natural History. It's basically a pelvis, some vertebrae, and femora. Mo Hassen (who works there) tells me that paratypes referred to Dacentrurus have consisted mostly of plate elements, but it's certainly not clear what Dacentrurus looks like. I'd almost suggest turning your stegosaur into Miragaia, just because it's so well known (by comparison).

2) England's "Torvosaurus" may actually be "Megalosaurus" after all, M. bucklandi in fact. There was a great talk synonymizing most of the ilia and femora assigned to different genera over the years to Megalosaurus bucklandi. Torvosaurus may still be a "megalosaur," but that's no longer clear, and whatever it IS, it's unique to North America.

3) Another fantastic paper discussing lips in dinosaurs (not by Witmer) by figuring out how many premaxillary, maxillary, and dentary foramina = lips or extra-oral structures (like in lizards). As it turns out, more foramina means LESS likely there are extra-oral structures. All ornithischians and theropods fell well below the "bare" category, suggesting they all have, at the very least, lizard-like lips. The same applies to sauropods, surprisingly. Actual fleshy cheeks may actually apply to hadrosaurs and ceratopsians.

A lot can change after just one conference, sir! :-D

Michael O. Erickson said...

"All ornithischians and theropods fell well below the "bare" category, suggesting they all have, at the very least, lizard-like lips. The same applies to sauropods, surprisingly. Actual fleshy cheeks may actually apply to hadrosaurs and ceratopsians."

So theropods, sauropods, and most of the Predentata (=Ornithischia) have lizard-like lips, while hadrosaurs and ceratopsians have cheeks? Or am I not reading that right?

Nima said...

I think Zach means that this new research suggests all dinosaurs had some sort of lips, lizard-like or otherwise. Of course the predentata with their beaks are very unlikely to have had LIPS over their beaks "disney style" but of course the conclusion that they had cheeks is only logical!

Basically all dinosaurs had EITHER lips or cheeks (but I can't think of a single species that has both.... though a large jaw adductor muscle could have served the same purpose as primitive cheeks for some types. As for sauropod lips... yes indeed they had them, Bakker did some good research there in the 1980s.

I'm also well aware of the Jurassic Park raptor mixup being traced back to Greg Paul. To his credit, Paul sincerely DID consider Deinonychus as a species of Velociraptor (their skulls are a LOT more similar than the typical Ostrom/Bakker reconstructions might lead one to believe!)

However, the majority of the field only uses "Velociraptor" for the type species V. mongoliensis, and Paul's taxonomic luping of the two was not accepted (he himself also abandoned it, it seems). So yes the JP raptors are indeed Deinonychus, BUT they are still a shade too massive for that genus as well as lacking any plumage... At least LIGHT plumage would make a bit more sense...

Now to Zach -

It's interesting Mo Hassan has some info on Dacentrurus, however there are also Portuguese specimens aside from the British ones. The same is true of Torvosaurus, they seem to resemble American specimens... in fact I wouldn't doubt the presence of Torvosaurus in Portugal, since Allosaurus also made it there!

Now Dacentrurus is presently a wastebasket taxon that MAY have some of Miragaia in it.

However, some of the remains are different and suggest a larger animal. Until more Dacentrurus is found, I'll keep my drawing exactly the way it is. I'm not being arrogant - just pointing out that when there's a scarcity of articulated evidence (rather than evidence of ABSENCE) then Dacentrurus can't really be discarded. In a nutshell, I don't believe that Miragaia was the only stegosaur in Portugal. There may well have been others besides Dacentrurus and Lexovisaurus as well (though I forget if Lexovisaurus has actually been FOUND in Portugal...)

Marica said...

Hey Nima,

Wow since 1994! You must have lots of drawings!

Did you ever do an exhibition of your work? I bet it will be a huge success and also very educational for little kids I would say.

I paint mostly landscapes, some portraits and some abstract (you know the boring stuff lol). I just paint for myself (or I should say I used to, because it's been ages now since I last painted something).

Have a nice week :)

Nima said...

I did an exhibition of dinosaur SCULPTURES actually... it was a pretty small-time thing though, just showcases in the local library back in 1998. But I had a lot of them... I wouldn't consider them great today, but they were eons ahead of anything most people my age could make. I used those little silica balls from shoe stores to make the eyes!

I do have a lot of drawings... over the years they look more and more like lifelike dinosaurs. Though the ones I did in 1994 were pretty awful (I was only 7 years old), they still looked like an animal with body parts, joints, perspective, and proportions - and not just a formless blob which you could expect from most 7 year old kids.

Zach Armstrong said...

Hi Nima, I haven't responded concerning the lips stuff yet as I was debating whether or not to start a blog (and I have been kinda loaded with school work). I have decided not to start a blog as I do not have the time. You make some legitimate complaints against some of my reasoning. But those are (comparatively) minor quibbles and do not in actuality affect the conclusion of my argument and the main points that deal with the biomechanics of theropod jaws.

Fine, let's forget about comparisons with crocodiles. All I want to say is that your comparison of lizards is eqaually bad: lizards are non-archosaurs, quadrapeds (ALL known theropods are bipedal), largely insectivores or small game hunters, poikilothermic (versus theropods which were likely homeothermic), all extant lizards weigh less than 100 kilos (and Megalania has in some estimates been reduced to about 350 kilos on average, but possibly up to almost 1.9 tonnes). The vast majority of theropods weighed at least 100 kilos, and many weighed over 1 tonne, and still a large number reached over 2 tonnes. Contrary to your initial arguments, komodo dragons are indeed venomous (see Wikipedia article here for more info), as are some other monitors and agamid lizards. Simply being terrestrial predators is not much of a similarity. Lifestyle and the way lizards capture prey IS relevant here, and that necessarily includes the venom that they possess in komodos. Also, like I said, in the vast majority of lizards they are insectivorous, catching small, squirmy prey. Lips probably help the insects from getting away too easy...giant theropods were not insectivores!

You say the foramina in crocs look "stretched", well some of them do, but not all of them. I have just been going over many of Paul's theropod skull reconstructions in PDoW and DoA and SABoD, and some theropods (including some Tyrannosaurus skulls) also have this "stretched look". I am "sorry if you cannot see that". Your statements about the similarity between theropod and lizard foramina are overstated (theropods had tightly spaced foramina compared to lizards and are far farther down on the maxilla than in lizards, and are far farther up on the dentary than in lizards). Furthermore, and as I have repeatedly said, foramina have nothing to do with the presence of lips! They are a red-herring! And you have produced no evidence to support otherwise.

As for your comment about homeothermic mammals: they do not have a line of foramina! There is no comparison there. Sorry. Sure, they have lips and are homethermic, but lack any other similar features with theropods.

As for sea snakes: fine it was a bad comparison behaviorally when talking about predatory behavior. But, habitat-wise, it is still valid since they are primarily aquatic like crocodiles, and still have their lips. You apparently think crocs had to lose their lips because they would have gotten in the way. Tell that to hyenas, lions, bears, etc. which have equally vigorous life styles. Living in water and mud has nothing to do wit the loss of lips (just ask the really violent male elephant seals!). If croc ancestors had lips, as you claim, you must come up with a reason that they lost them!

Zach Armstrong said...

Nima, I will now reprove each of your other complaints with my arguments, in order, with asterisks in the same fashion that you did:

*fine, maybe crocs were a bad comparison in your opinion behaviorally, but the foramina are actually quite similar. I'm sorry you can't "see it". I tried to play your game with foramina, but the truth is that they have no relevance to whether there are lips or not.
*Foramina have no connection to the presence of lips. Lizards have a line of foramina and have lips. Mammals do NOT have a line of foramina and have lips. Some anurans have a line of foramina and have lips, while others do not have a line of foramina and still have lips. I am using living animals as my proof: Correlation does not imply causation. You are wrong.
*convergence happens in animals with similar lifestyles. Theropods and lizards do not have similar lifestyles. This objection is irrelevant. Furthermore there is no practical usefulness for lips in theropods that would have made them develop them.
*"lips" may be old, but they are not homologous in lizards and mammals. You are wrong in saying crocs are the only group that lost them completely as so did birds and turtles.
*again, forget about crocs and concentrate on the fact that lizards are not a better model (i.e., quadrapeds v. bipeds, poikilotherms v. homeotherms, small v. large, different skull morphology and biomechanics, general ovserved/inferred behavior, etc.)
*you're "Diapsida" comment is irrelevant since you infer from the foramina in extinct taxa that they had lips. As I have already shown, foramina have little if nothing to do with the presence (or absence) of lips. So your inference is incorrect when applied to extinct taxa, which makes your statement debatable at best. Remember, crocs, aves, and chelonians lack lips!
* I fail to see the relevance of a deep jaw to the presence of lips. This is a non-argument (and could even here apply your own comment about the "tactic is very much like a very inexperienced lawyer, to sow doubt by using confusion, unrelated facts, and using reverse logic... that does not hold up in true science").
*I do not imply (or apply) an aquatic lifestyle to theropods. The "drying out" comment is a bad argument--we cannot know this for sure, and is mere speculation based on preference. If lips were used to keep the mouth from drying out, why do many aquatic animals still have lips (i.e., seals and sea snakes)? How come tortoises and birds do not have lips, then, to keep their mouths from drying out? At any rate, theropods had an overbite, which made their mouth seal tight even without lips, and they replaced their teeth so often they did not have to worry about tooth decay.
*sea snakes do have something to do with it. You implied an aquatic lifestyle gave crocodiles the option to lose their lips. Sea snakes prove this argument false. As for basal Amniota having lips, this is an assertion you made up, not a proven scientific fact.
*yes, crocs and theropods do show a divergency in their gross morphology, but (as mentioned above) so do lizards and theropods! Their closest relatives and ancestors (birds) have no lips, and have the best comparison behaviorally and morphologically! It'd be better to assume that theropods had a beak-like rhampotheca than lips!
*So? Neither can you. Lizard foramina are no closer to theropod foramina than croc foramina are to theropod foramina. Theropods have more densely packed foramina than lizards do, they are proportionally farther down on the mazilla than in lizards, and the foramina would have been completely covered by the upper teeth on the dentary, and would have punctured through any supposed lips. Furthermore, many theropods have random foramina farther up on the maxillary and premaxiallry as in crocs, but not as in lizards. This means that theropod foramina are equally as different from lizard foramina as they are in crocs. I rest my case (for the time being).

Nima said...

Whoa man calm down... I'm not sure what the meaning of all this is so I'll keep it simple.

Let me get this straight - you debated with yourself for 5 days whether or not to start a blog... and then after I'd pretty much rested my case and the debate had died down, you send me a shower of komodo dragon venom.

Ugh. I thought we were friends.
I suppose you're not up for my sauropod challenge either, huh?

But sarcasm aside, I doubt that my making one error (the venom thing) makes your rage any more persuasive. I already stood corrected on that point by Mike.

But once again, you contradict yourself. First you claim that lizards have lips to hold onto insects, hence theropods don't need them because they are mostly large and not insectivores. So far I follow...

But then you turn around and say that I am wrong about crocodile lip loss because of croc lifestyles, look at mammal predators that are big, rough, vicious, and have lips...

Wait a second, NONE of these creatures are small insectivores! Something smells fishy...

So I suppose lips are NOT only for small insectivores, are they? Apparently lions and suchlike also need them to hold onto prey, or else they serve some OTHER PURPOSE you have omitted... like protecting the teeth from the elements, or preventing the moist gums from drying out, both of which ARE legitimate benefits of having lips.

Crocs are aquatic, their mouths will never dry out AND they're not that moist to begin with. Do crocs even have saliva? What's more, in water exposed teeth are less likely to be damaged by collisions, dust storms, grit, etc. than on land. And FINALLY, have you noticed that croc jaws have all those notches that the teeth fit perfectly into? That way they have something to butt up against so they are not as prone to getting painfully whacked and cracked.

Theropods have no such system of overlap and notches. Furthermore most have much longer teeth than a croc with the same skull length. Croc teeth are mostly short and do not protrude too far beyond the gumline.

Now tell me this.... if foramina are a "red herring" that is totally irrelevant to the presence or absence of lips, then WHY do you argue that theropod foramina look oh so much like crocodile facial pits and therefore indicate lack of lips???

Wouldn't it be just as likely that they HAD lips, since foramina are "irrelevant" to lips? Or are angry bold letters more credible than logic?

Nima said...

If you want to debate, keep it civil... and if you can't do that, at least stay within the bounds of your own initial arguments instead of constantly violating them.

Furthermore, there is no need to "come up with a reason" why croc ancestors lost their lips. I already gave a reason and then some. Go back to the part about crocodile vision and brains. Furthermore, even if you are unwilling to admit to the obviously VAST differences in hunting styles for crocs and mammal predators, at the very least it's undeniable that lips are an ancestral amniote characteristic. Every amniote group alive today has them except crocs and turtles (and turtles are even FURTHER from dinosaurs than those awful lizards!)

Lips are found in both reptiles and mammals - both diapsids and synapsids. And I doubt they evolved independently from a lipless common ancestor. This is not a personal attack so please don't take it personally... but all you have to offer is crocodiles. Your entire argument hinges on citing crocodiles and exaggerating the the appearance of theropod maxillary foramina to argue they were basically big crocodiles. In fact the burden of proof is on YOU for assuming that lipless crocs are a universal ancestral condition of amniotes rather than a highly specialized, derived one, when the entire fossil record indicates otherwise... DO you believe that all amniotes or all diapsids had lipless ancestors?

I'll say it again. You only have crocs. I have nearly ALL the rest of Diapsida! AND synapsida! Did some theropods likely have minimal or reduced lips? Yes. Did they ALL absolutely lack lips ENTIRELY, exactly like crocs? Well, is Bernie Madoff an honest man? Didn't think so.

Perhaps the very nature of this debate is flawed. Because so far all you have done attack without defending your own flanks adequately. You stretch the truth almost to the breaking point with these bloody "irrelevant" foramina to give theropods croc-faces, and then accuse me of promoting lizards as THE ideal model for dinosaur lips.

Indeed, I made no such claims. It's sad that we don't have a good live model for dinosaur lips. I NEVER said lizards are an ideal model, an ideal model would be a living Allosaurus! But sadly, in purely physiological comparisons of the lips and foramina, lizards and other lipped amniotes are the best we've got for now. Lips, no croc-notches in the jaws, and even some larger carnivorous mammals retain at least a few foramina to anchor lip muscles.

Even tuataras have lips, and they have barely changed since before the dinosaurs. The only group of toothed reptiles surviving today without lips is crocodylia. The rest of the toothed amniotes did NOT just randomly sprout lips independently. It was an ancestral trait. Crocs are the EXCEPTION, not the rule. You do realize, I hope, how circular and "beat around the bush" your argument is sounding right now... a bit like Jack Horner grasping for straws when his extreme lumping of separate species as juveniles of other, larger species fails to stand up to good research.

Not all amniotes are crocs. They don't all live like crocs or have the same sort of brain and behavior. And if foramina are irrelevant, they do NOT indicate a lipless croc-like mouth.

If you can't produce anything more solid than crocs, there's nothing more to debate.

Michael O. Erickson said...

Amen, dude.

I won't say anything more substantial than that because what you said is pretty much what I had in mind to say. Would you mind explaining to me how this mind-reading stuff works? LOL

Nima said...

LOL yeah man, I'll send you an email. Some of this stuff is pretty heavy though, and you won't believe where it came from... while the rest is as simple as watching speeches and debates you agree with in principle and noticing what's wrong with them in practice and delivery.

BTW just to make things clear, I'm not bitter or angry at Zach Armstrong in any way, I just think he's dead wrong on this particular issue... and I don't think anyone should ruin their day over something like theropod lips ;)

Zach Armstrong said...

Sorry, Nima, for getting way too heated in my last comments, but you do have to admit you kinda egged me on my calling my tactics, and I quote, "Your tactic is very much like a very inexperienced lawyer, to sow doubt by using confusion, unrelated facts, and using reverse logic... that does not hold up in true science." Excuse me, but I felt that that was a pretty hefty insult, thank you very much. But, I'm gonna let that go.

I will try and tone down my rhetoric, but I still must respectfully disagree with you concerning the lips issue.

I do want to say this, I did not debate with myself for fived days whether to start a blog. In fact, I pretty much made up my mind within 5 minutes. Like I said, I've been busy with school. I think you would understand that.

I think friends can have heated disagreements, but you are right, I was out of line with the bold letters, sorry 'bout that.

About mammalian lips, you are right that they have a function...but it is not primarily to keep the mouth from drying out or protecting the teeth from the environment. The primary role for lips in mammals is to help infants be able to suck milk from the mammary glands. They also serve in communication (both visual and aural).

So yes both mammals and lizards have "lips" but they are not really the same lips. In fact, only mammals have true lips, lizard "lips" are not really "lips" at all.

You make a very good point about dust and sands, etc., roughing up teeth, in mammals, which do not continuously get a new set of teeth every couple of months or so like crocodiles and theropods. We have fossil evidence that shows theropods went through their teeth like sharks. So, if one got damaged, it was easily replaced. Lips simply aren't needed for the purpose they are in mammals for keeping out erosionary elements. they continually had a new set of teeth to look forward to.

I must also repeat, for the record, that mammal and lizard lips are not homologous and are mechanically very different. One major difference: mammal lips are highly mobile and muscular, while lizard lips can only be slightly flared and have little musculature. So lips in mammals serve very different purposes, purposes that theropods would have had no use for: they do not lactate, did not have the facial muscles that mammals do, and likely did not need muscular lips to communicate (after all, their closest relatives birds don't).

It is also true that theropods do not have the system of overlap and notches that crocs do, but it really is not necessary. The overbite in theropods and the fact that the dentary was narrower than the premaxillary and maxillary complex means two things: one, the teeth in the dentary were completely covered by the bone in the upper jaw, so unless the skull was smashed in, they were safe. Two, the teeth in the premaxilla and maxilla rested right on the dentary when the jaw was shut, creating an effective brace.

Zach Armstrong said...

(continued from last comment...)

And you are right again, theropod teeth are in general much longer proportionally than croc teeth. In fact, in some tyrannnosaur specimens (such as "Stan", BHI 3033), the teeth extend beyond the dentary. Now, formerly I was under the impression that this was because the teeth were 'loosened' out of the socket, and thus protruded extra long (as I mentioned in my comments way earlier in this discussion). However, some research that I was not aware of shows that this is not the case: the teeth in BHI 3033 are not displaced. Which I find hard to believe, but it is evidently true. What's even more strange is that new teeth are pushing "out" the old teeth, but the roots of the "old" teeth have not been absorbed. So, if this guy had lips, his upper teeth would have pierced straight through the lower lips, babirusa-style. Now, I would find this to be highly strange, unlikely, and most un-parsimonious, and thus reject the idea of tyrannosaurs having lips. In fact, all long-toothed theropods teeth would have pierced their lower lips clean through. This precludes tyrannosaurs, Ceratosaurus and kin, and Torvosaurus from having lower lips. Furthermore, the upper lip would have to be ungodly long to cover the upper teeth by itself. No lizard has such long lips, and theropod lips are definitely not comparable to mammal lips (as I explained above). This effectively eliminate these three groups of theropods from having lips, and even in other theropod groups where the teeth were not hyper-ling, they were still too long to allow lips on the bottom of the jaw. No animals alive today has lips only on the top jaw, so I find this case to be most un-parsimonious and thus reject such an idea.

As for the red-herring about foramina and my comparison with crocs, my point was not to say that because theropods (in my view) have similarities in their foramina to crocs then they must of had no lips, but to show you that foramina and lips do not go hand-in-hand. That was the point of the comparison, to show you that foramina, no matter which kind or how they are arranged, are not the smoking gun for the presence of lips that you make them out to be, nothing more and nothing less.

You said that since I state foramina are irrelevant to the consideration of lips, then that a lipped-state for theropods should be equally as likely. While that is true for a null-hypothesis, I have given you plenty of biomechanic, behavior analysis and a good extant phylogenetic bracket (i.e., the closest living relatives of theropods are both lipless) to show you why theropods would not have had lips.

To further drive my point on foramina home, look at this mallard skull here, if you please. Notice all the foramina at the tip of the mallard's bill. Now look at this picture of a Tyrannosaurus skull in front view here. These both have very similar foramina patterns at the foremost edge of their skull. Now, using your reasoning that foramina have something to do with the presence of external oral structures, we should thus conclude that Tyarannosaurus had a beak, since ducks have beaks, and that's why the foramina are there. Furthermore, you said that no living animal with a beak has lips. So if T. rex had a beak, it must not have had any lips, then, in your view. Otherwise, you must concede that the presence of a beak does not preclude lips, which means you must explain why birds do not have lips with their beaks and why turtles do not have lips with their beaks, if lips are basal to the Amniota. Thus, your line of reasoning completely falls apart.

Zach Armstrong said...

(continued from last comment)

If, though, on the other hand, you accept that foramina having nothing to do with external oral structures, then we avoid this whole messy line of reasoning. Then we are back to comparing biomechanics, behavior and the EPB (extant phylogenetic bracket) to see whether theropods had lips. As I have already shown, all of these lines of evidence indicate theropods do not have lips.

You are also right that bold letters do not make a bad argument sound. However, my argument is actually quite sound. Furthermore, I deeply regret if I offended you by using bold letters. I am sorry, it won't happen again. I would be very disappointed if that got in the way of our discussions, as you are a great paleoartist, and have good anatomical insight (except, in my opinion, on lips ;) ), and I enjoy discussing paleontology with you, and would be sad if this discussion got in the way of that. So again, I am sorry if I have got heated at times.

Zach Armstrong said...

Hi Nima, I am now responding to your second comment. I will try my best to keep it civilized. I will respond point-by-point:

Yes, you do still need to come up with a reason why crocs lost their lips. Your main arguments is that they did not need to worry about their mouths drying out since they were in water all the time and because of their violent hunting styles. As I have said before, their are numerous equally aquatic animals other than crocs that still have lips: seals, sea lions, walruses, elephant seals, dugongs, manatees, hippos, sea snakes, marine iguanas, and the list goes on. Furthermore, elephant seal (especially males) have a very violent life style. On the other hand, many terrestrial animals live violent lifestyles and still have lips. So your reasons for lipless crocs are poor ones. And you say that lips are an ancestral trait...that is at the very least debatable. Out most primitive modern tetrapods (turtles) are lipless. Furthermore, as I said lizard and mammal lips are not homologous, which means they did not inherit them from a common basal amniote ancestor, so even if early Amniotes DID have lips, that is not a reason for theropods to have had them. You also say you have the whole amniote grop with you, well not quite: extant amniotes include turtles, squamates, sphenodonts, crocodiles, mammals, and birds. Of these, turtles, birds, crocs, some monotreme mammals lack lips, and so do some/most cetaceans (whales). On the other hand, lizards, snakes, sphenodonts (tuataras) and most placental mammals have lips. Hardly what I would call the entire Amniota having lips.

You say I all I have to offer are crocodiles, but that is plainly not true. I DO believe that many basal amniotes lacked lips. In fact, this article here gives a nice explanation on why cynodonts may not necessarily had lips.

Furthermore, cynodonts were synapsids, which partly falsifies your claim that you have "all the synapsida" as evidence.

While I don't think Bernie Madoff is an honest man, that is logically irrelevant to this argument. I find it most parsimonious (from looking at the EPB) that theropods lacked lips. The biomechanical evidence of how theropod jaws work supports my case.

I will contradict that your statement that I have not adequately defended my flanks: I have, providing plenty of evidence and food for thought. And I have done so by myself, at least you have Michael on your side giving you moral support. So the discussion is slightly tipped in your favor on the basis of the number of people involved on your side.

Furthermore, I never said you promoted lizards as the IDEAL model, what I did say is that you implied that they were better models than crocs and birds, which are more closely related to theropods than lizards. On the flip side, you HAVE said that my only example was crocs, which is not the case, I have birds and turtles as well (not to mention monotremes and whales which you would probably disqualify outright).

Au contraire to your statement, lizards are not the best extant comparison. As I said in yesterday's comment, crocs and lizards are equally bad models based on behavior, and are equally good models based on how both their foramina differ by equal amounts from theropods.

And I must address this, you said, "even some larger carnivorous mammals retain at least a few foramina to anchor lip muscles". That is plainly false, foramina do not anchor lips. Muscles and other tissue anchor lips, and muscles and tissue are not anchored by foramina. ALL that foramina do are supply blood vessels and nerve endings. Look up what the definition of foramina is. True, mammals do have foramina, but they are not in a line, and they do not "anchor" lips. That is just not anatomically true. The fact that mammals have bigger, more muscular lips and FEWER foramina than lizards (and significantly so) show that to be the case.

Zach Armstrong said...

Finally, Nima, you talked about tuataras, and that the only group of toothed reptiles without lips are crocs, and how amniotes "did not just randomly sprout lips independently". Well actually, that latter statement is the case (except for the random part). Mammal and lizard lips are not homolgous. Only tuatara, snake and lizard lips are homologous, as they are all Lepidosaurians. Furthermore, that cynodont reference I gave you in an above comment indicates that synapsids independently were formed with lips and are not homologous with lizard lips. Amniote lips were developed independently.Furthermore, mammal and lizard lips are only superficially similar, and otherwise lack any real internal similarity.

Crocs may be an exception when compared to other Lepidosaurs, simply because they have teeth and are lipless. But that really isn't relevant, since croc jaws are far different from lizard jaws biomechanically, and so are theropod jaws--they are quite different biomechanically from lizards. The only toothed reptile outside the Lepidosauria ARE crocs, so your argument is weakened here too; in other words, you have no example of a non-Lepidosaurian toothed and lipped reptiles outside of crocs, so your comparison fails. The same applies when crocs and theropods are independently compared to mammal jaws, they are too biomechanically very different.

You said, "If you can't produce anything more solid than crocs, there's nothing more to debate." I have produced plenty of evidence besides crocs (i.e., biomechanics, other comparisons, flaws in your arguments and logic, etc.), biomechanics IS solid (you just haven't addressed it, or any of my points based on it, at all), and as such, the debate continues.

Nima said...

I see a lot of fancy wording, but sadly not much pith in the cross-section.

"As I said in yesterday's comment, crocs and lizards are equally bad models based on behavior, and are equally good models based on how both their foramina differ by equal amounts from theropods."

TRANSLATION: "basically there's no better proof from crocs than from lizards."

"...you must explain why birds do not have lips with their beaks and why turtles do not have lips with their beaks, if lips are basal to the Amniota. Thus, your line of reasoning completely falls apart."

TRANSLATION: "basal features can NEVER EVER EVVVVERRRR be lost or replaced by something else" - wait, if this is true, then every duck must have a beaked ancestor and so must every turtle.... was the ancestor of all amniotes beaked, or did it have soft fleshy lips? No offense, but come on now, you do accept evolution as valid, right?

If you accept that birds evolved from theropods, then it follows that a lipless beaked animal can have non-beaked ancestors who may well have had lips. Just like a hard-faced crocodile descends INEVITABLY from some lipped amniote ancestor...

Now lets get something straight here... when I say "lips are a basal amniote trait" I do not mean huge honking mammalian lips. I mean primitive, short lizard-like lips that are then free to evolve into whatever is needed. And if foramina are not needed for these, I'd argue that since both lizards and tuataras have them, the "most parsimonious" way would be to assume ancestral amniotes all had lips too. Remember, beaks are a SPECIALIZATION. They EVOLVED from non-beaked ancestors! This was the case with birds, rhynchosaurs, and dicynodonts, and it was almost certainly the case with turtles. All permian anapsids had teeth, not beaks. And they likely had those little lizard lips too. There is NO SUCH THING as a "basal beak".

You also cite turtles.... nice job, an anapsid. What do these creatures have in common with dinosaurs again? Even milk-suckling mammals would be a closer model... at least synapsida diverged closer to the line of diapsida...

This is why I don't even like the label "reptilia" - it lumps totally unrelated animals together - anapsids with diapsids.... of course, if all of amniota are "reptiles" then all mammals and birds automatically become reptiles as well... Turtles may be "reptiles" in the colloquial definition bu they have very little in common with any other group of "reptiles" - so they are NOT a good line of evidence. You were better off with just the crocs!

Nima said...

In fact crocs are closer to dinosaurs than any of the other "reptiles" are, BUT they are also far more restricted to the water, and their body design is far more squat and radically UN-DINOSAURIAN than their land-dwelling crurotarsan ancestors. Their brains also differ markedly from dinosaurs, their vision being primarily based on movement. In addition they are ambush predators with flattened snouts and not much risk of tooth breakage compared to long-toothed, deep-skulled theropods. YES I realize that theropods (and crocs) replaced their teeth. But STILL, breaking or damaging the root of a new tooth that isn't ready to fall out yet would be INCREDIBLY painful. And without lips, the risk of such breakage in even intraspecific combat between large theropod would be unacceptable high.

Also, lipped theropods would NOT be piercing their lower lips with their teeth. One of the best things about having lips is they can RETRACT and are not permanently frozen structures. Ever thought about a theropod's lower lips being smalle than the uppers, and tucking neatly inside its upper teeth? There's no risk of "babirusa syndrome" there...

And do not misrepresent my statements. I said only that theropods HAD lips, not that the lips were big enough to cover their huge teeth. Indeed, I NEVER draw a theropod without showing the teeth at least half exposed. Some species like Ceratosaurus and Torvosaurus had teeth far too oversized for lips to realistically cover more than 25% of any given mature tooth. Fully covered teeth in my view would be total overkill.

P.S.

I'd like to see your own illustrations of lipless theropods... I think you've already seen enough of my lipped ones to see that MY interpretation of dinosaur lips isn't all that strange, outlandish or extreme.

Zach Armstrong said...

"TRANSLATION: "basically there's no better proof from crocs than from lizards." "

Actually, the translation works in the reverse (I like how you always put a negative spin on my comments, and a positive spin on your comments...): "basically there's no better proof from lizards than from crocs," concerning the lip issue. ""...you must explain why birds do not have lips with their beaks and why turtles do not have lips with their beaks, if lips are basal to the Amniota. Thus, your line of reasoning completely falls apart. TRANSLATION: "basal features can NEVER EVER EVVVVERRRR be lost or replaced by something else" - wait, if this is true, then every duck must have a beaked ancestor and so must every turtle.... was the ancestor of all amniotes beaked, or did it have soft fleshy lips?"".....

Wait a minute, you are the one who says theropods would not have lost their lips. What I did say (you are quote mining, you did not quote the relevant previous immediate context of what I was saying) was that ducks and tyrannosaurs have similar foramina at the end of their skulls, which, by your reasoning means they must have also had beaks. You also must admit that your reason for turtles and birds not having lips was because they had beaks. My point to show that line of reasoning is false. Basically, then you admit that at some point in the evolutionary history, then, that bird's ancestors must have had beaks AND lips. Which means your excuse for birds not having lips because of their beaks (and your explanation for turtles, too) falls apart. I'm sorry, but you can't have it both ways Nima. If you accept that foramina have something to do with lips and other external oral structures, then you also have to accept that they have something to do with beaks, which means you need to start drawing your theropods with beaks AND lips. But previously, you said beaks preclude an animal from having lips (i.e., "that's why turtles don't have lips"). That reasoning is circular and false.

I also must repeat that lizard and mammal lips are NOT homologous. They did not evolve from a common structure, they evolved separately. If they are not homologous, their is no reason to think the most recent common ancestor of mammals and lepidosaurs had some type of lip. You have failed to show, and miserably so at that, that Amniota had lips as a basal characteristic. Even comparisons with turtles (and tortoises which are LAND based, thus a water-loving lifestyle had nothing to do with them losing lips) which are the most basal extant Amniotes, show your assumption is wrong.

Furthermore, if you even read that link about cynodonts that I gave you above, some authors have also come to the conclusion that formina have nothing to do with lips, and that cynodonts probably lacked lips!

So if basal mammalian ancestors (cynodonts) lacked lips, then lips are not a basal Amniote trait! They had to evolve at least twice.

Furthermore, modern monotremes (which are considered to be basal mammals), lack lips. Again, your assumption that lips are basal is false.

My point in citing turtles is not to show that theropods closely resemble turtles. I NEVER said that. What I DID say is that they are basal amniotes, and lack lips. What you said is that you had the vast majority of the Amniota on your side, and I provided turtles (and birds, and monotremes, and some whales) as an example to prove you wrong. I never said they were theropod analogs. What I was trying to do was refute your point that all amniotes besides crocs had teeth.

My point about turtles was not that they are "reptiles", but that they ARE amniotes, which was the focus of your point.

Zach Armstrong said...

(continued from last comment)

You seem to think lips would prevent damage to the teeth. Sorry, lips are soft and if a sauropod kicked a theropod in the face, even if it had lips, those teeth were going to fall out. If lips protected teeth from being the subject of an attack, then when a person gets punched in the mouth, their teeth would not fall out; but that is not the case, if someone is punched in the mouth (even if the mouth is closed) the teeth will still be painfully moved! Your point here is completely illogical and has no basis in reality.

Furthermore, you even admit that the lips would NOT have covered the teeth all the way in theropods, so again, your point that lips would have protected the teeth (and thus would be beneficial evolutionarily) in that aspect is false.

You said, "Also, lipped theropods would NOT be piercing their lower lips with their teeth. One of the best things about having lips is they can RETRACT and are not permanently frozen structures. Ever thought about a theropod's lower lips being smalle than the uppers, and tucking neatly inside its upper teeth? There's no risk of "babirusa syndrome" there..." Well, you are wrong. Theropod teeth would have pierced the lower lips. If they had lizard lips, as you suggest, they could not "retract", whatever that means. In order for them to "retract" to let the large teeth in, the lips would have to be bared like a horses' lips in order to accommodate those honkin' huge teeth! Theropod's did NOT have mammal style lips, at any rate and lizard-type lips would have gotten in the way and pierced through on the bottom.

If theropod lips did not cover all of the teeth, as you suggest, then there is no real usefulness for the lips at all, even using your poor arguments for lips. All your arguments for the practicality of lips wouldbe that the lips would "protect" the teeth. But if the distal end of the tooth (the sharpest and most beneficial part for a predator) is exposed, then of what use are the lips?? Furthermore, does any lipped animal today have teeth that protrude beyond their lips?

Again, Nima, your support for theropod lips is based on lepidosaurs and mammals, which are not at all dinosaurian in any of their habits and the relevant biomechanics. Foramina have nothing to do with lip attachment, as you wrongly assert. Your whole argument is very flimsy. You all but ignore the EPB, and ignore all my biomechanically based arguments. Furthermore, you have no solid reason for lips in theropods. They are completely unneeded.

I must add that I am not mad at you, but very frustrated with your poor arguments for lipped theropods.

Theropods did not have lips!

Nima said...

Zach, what can I say - don't post a comment unless you understand what's going on, because you are once again oversimplifying and making loads of fallacies. Keep in mind that I patiently refrain from deleting your mile-long bashes, but that does not give you free reign to misrepresent every possible extreme OPINION as fact.

Now you accuse me of "quote mining". Actually, I only had enough time then to point out only the most obvious flaws in your extreme prejudice against lips.

You really want a point by point refutation?
I say, pick your battles better.

"ducks and tyrannosaurs have similar foramina at the end of their skulls, which, by your reasoning means they must have also had beaks."

>> NOT TRUE, and not what I said either. Those maxillary foramina that are present above the gumline at the tip of the snout, have different purposes in different creatures. They mainly anchor hard, tough tissue very tightly. In birds this is a beak, in dinosaurs it was simply very rough skin. Nobody will mistake the mouth of T. rex for a beak. Indeed, the two are worlds apart. Foramina serve different functions in different animals. Unless you're a Creationist and think that they can't EVER evolve and modify pre-existing structures towards new uses... Weren't mammal ear bones once jaw bones? Weren't beetle wing cases once wings? Well foramina did NOT always anchor beaks!

"Basically, then you admit that at some point in the evolutionary history, then, that bird's ancestors must have had beaks AND lips. Which means your excuse for birds not having lips because of their beaks (and your explanation for turtles, too) falls apart. I'm sorry, but you can't have it both ways Nima."

>> Reality check: I'm only having it ONE way. Once again you are lying about my statements. I NEVER said that bird ancestors had both beaks and lips. They obviously lost lips in the process of developing beaks. Take a look at Archaeopteryx and later forms like Ichthyornis... they have BEAKS with some teeth still remaining, but no hint of lips.

For over 100 years these bird fossils have proven that bird ancestors lost their lips long before the beak became what it is today - indeed, lips were already gone even in proto-beaks with teeth! So NO, birds never had both lips and beaks at once. Your claim has no bearing on my ACTUAL statements at all.


"But previously, you said beaks preclude an animal from having lips (i.e., "that's why turtles don't have lips"). That reasoning is circular and false."

>> No it's not. I never contradicted myself. Beaks DO preclude an animal from having lips. Ever seen an animal that has both? Didn't think so. I said that foramina anchor lips and skin in theropods. It was YOU who spontaneously brought birds into this and started putting words in my mouth.

Now bird beaks DO have some foramina, but the duck's waxy beak is an exception to the rule: foramina are NOT common on most birds. Look at this eagle skull, you only see a few:

http://www.childrensuniversity.manchester.ac.uk/interactives/science/teethandeating/discovermore/gallery/full/bird_01.jpg

Foramina do anchor beak structures in birds - just as they ONCE anchored lips in theropods. Is it so inconceivable for you that structures in animals can EVOLVE to suit new purposes and lifestyles?

Nima said...

"I also must repeat that lizard and mammal lips are NOT homologous. They did not evolve from a common structure, they evolved separately. If they are not homologous, their is no reason to think the most recent common ancestor of mammals and lepidosaurs had some type of lip."

>> An empty OPINION at best. Prove that they did not have a common lipped ancestor. Basal reptiles ALL have the skull structure necessary for lips much as in lizards and tuataras today. They did not have beaks like turtles or lipless plank-faces like crocs. Only in your world are they non-homologous. And there is NO PROOF that Cynodonts lacked lips. Now if you're talking DIcynodonts, I'm with you there... but aside from ignorant BBC narrators, nobody seriously considers them as mammal ANCESTORS. And yes, they evolved from non-beaked (and probably lippy) synapsids...

"Even comparisons with turtles (and tortoises which are LAND based, thus a water-loving lifestyle had nothing to do with them losing lips) which are the most basal extant Amniotes, show your assumption is wrong."

I never said that living in water causes lip loss. It is only ONE of many FACTORS in crocodile lifestyle that led to lips being more of a hindrance than a help. Did you even READ what I wrote about croc behavior and reactivity?

Furthermore, there's a good reason tortoises didn't re-evolve lips when they got back on land - they didn't re-evolve lips because they had no need to re-evolve TEETH. Their beaks were perfectly adapted to stripping and swallowing plants. It's interesting to note that tortoises only became common AFTER the Mesozoic, once plant-eating dinosaurs were wiped out. Apparently, barring the inevitable mass extinction, lips give you an edge! Every lipped animal that I know of has teeth or similar structures. Some beaked animals once had teeth, but no beaked animal re-evolved lips. Now it COULD happen, but by and large evolution does not normally reverse itself. Tortoises are a bad example ANYWAY. They are NOT "basal amniotes".

Let's define basal here - it does NOT simply mean "primitive" - it means close to the ROOT or BASE of the crown group from which more derived animals evolved. Turtles themselves are quite derived by cold-blooded standards. By BASAL REPTILES I mean the very FIRST amniotes, immediately after carboniferous amphibians, before the various -apsids became divergent. They had teeth and no beak. Turtles evolved in a radical direction on their own. True turtles are not known from any earlier than the Triassic.

"So if basal mammalian ancestors (cynodonts) lacked lips, then lips are not a basal Amniote trait! They had to evolve at least twice."

>> No no, you have not proven that Cynodonts lacked lips. Only that SOME authors doubt they had lips. Stop making assumptions based on something that totally LACKS any sort of consensus. ALL YOU PROVE is that in synapsids, foramina have little to do with lips, as in most mammals. Now if mammals can have lips without a lot of foramina, so could cynodonts (unless they had beaks, which they don't). Also, SOME of their foramina higher up on the jaw anchored whiskers, so you can't compare their facial skin with that of dinosaurs. They had ALREADY evolved mammalian faces. Think about it - foramina and lips can BOTH EVOLVE OVER TIME. And they HAVE EVOLVED and CHANGED many times, even if you only go back to the eocene!

Nima said...

Basically you argue that beaks are basal to amniotes, even though no amphibian has beaks, miraculously the lipped amphibians turned into lipless turtle-like "basal amniotes" which gave rise to mammals that miraculously lost their beaks and gained lips again! Now if this is NOT your view, please ELABORATE on what "basal" means to you. Turtles are NOT basal to all other amniotes. Otherwise we would find turtle-like features in the history of crocs, lizards, and dinosaurs. But alas, there's not a single anapsid skull, internally placed scapula, shell, or beak among any of them!!!

I argue the opposite - that LIPS are basal, since amphibians have primitive rubbery lips, and most species of reptiles have lips, and things like beaks are independently derived in turtles, birds, and platypus. TRUE basal (i.e. ANCESTRAL) amniotes had LIPS, not beaks.

The biggest hole in your turtle argument is that the MOST basal turtles still alive today, SOFTSHELL TURTLES, DO HAVE LIPS! They hail from the late Triassic, before turtles even HAD beaks. Their lips are rubbery, almost fish-like, and LACK A BEAK!

http://myfwc.com/images/Newsroom/News_SoftshellTurtle.jpg

http://en.wikipedia.org/wiki/File:Pelodiscus-head.jpg

WOW, I guess your "basal" amniotes really do have lips. And as the second pic shows, they can even distend them!

I would stop here ordinarily... but I see even more flanks are exposed!

Nima said...

But you continue making pointless extreme comparisons that have nothing to do with MY arguments...

"Sorry, lips are soft and if a sauropod kicked a theropod in the face, even if it had lips, those teeth were going to fall out... if someone is punched in the mouth (even if the mouth is closed) the teeth will still be painfully moved! Your point here is completely illogical and has no basis in reality."

>> Lips prevent SOME damage not all. You make three MAJOR errors here:

1. Human lips are far softer and more prone to injury than any scaly creature's lips

2. Lips are not a shield for the teeth, but in theropod they likely DID help protect against INTRA-SPECIFIC combat. Look up what that word means.

3. You are attacking a "straw man". I never said ANYTHING about a Sauropod deciding to slug their pursuers. Of course a sauropod could take them out. A sauropod could also kill a predator with no lips. Did I EVER say lips were an anti-sauropod device?

But tough, scaly lips were definitely useful in protecting the teeth in head-butting matches BETWEEN theropods. Many large theropods, including most allosaurs and tyrannosaurs, had short blunt "horns" above the eyes and butting ridges on the snout. Now since MOST theropods (and even some tyrannosaurs) had sideways vision, they would most likely fight laterally rather than head on.

Imagine you're an Albertosaurus. You size up your rival. You face each other oppositely, your right face to his right face. Then you toss your neck and diagonally whack upward with your nasal ridge straight into his face! Well if it weren't for tough lips, hit hard enough and his teeth would likely crack at the ROOT!

Again, this is far less damage than a sauropod could do. But (LOL) I never claimed lips were meant as an anti-sauropod lifesaver!
Who exactly are you debating here anyway?

"Theropod teeth would have pierced the lower lips. If they had lizard lips, as you suggest, they could not "retract", whatever that means. In order for them to "retract" to let the large teeth in, the lips would have to be bared like a horses' lips in order to accommodate those honkin' huge teeth!"

>> This is a BARE-FACED MISREPRESENTATION OF MY WORDS. I said RETRACT, I did not say extend or widen up to "accomodate". My point is that Theropods' lower jaw was sufficiently narrower than their upper jaw so that even with lips the whole thing could fit comfortably inside the upper jaw.

In my model, the upper teeth do NOT tuck into the lower lips, they simply overlap them! The lower lips end up being covered by the upper teeth...

Like THIS:
http://triassica.com/My%20Pictures%20from%20computer/30.7.06%20T%20rex%20tooth/T%20rex%201.jpg

And THIS:
http://2.bp.blogspot.com/_m6sVhskT_Fs/R5D4CCDH8-I/AAAAAAAABdc/NXDXv0IBTgc/s1600-h/trex_ja_gonzalez_MACN.jpg

(drawing by J. A. Gonzalez) - see the lips? Not very big, but then they don't need to be! And the lower lips are hidden!

EVERY artist I know of also illustrates their big theropods this way! Greg Paul, Luis Rey, Raul Martin, Larry Felder, Julius Csotonyi, Mark Hallett, John Conway... But they're all "ignorant" with "flimsy arguments", right?

Nima said...

"But if the distal end of the tooth (the sharpest and most beneficial part for a predator) is exposed, then of what use are the lips?? Furthermore, does any lipped animal today have teeth that protrude beyond their lips?"

>> FIRST, the distal end of any tooth, no matter what animal, is NOT filled with nerves. There are no nerves the the sharp tip of a T. rex tooth. Nerves are in either dental pulp, or deep within the center of the tooth. If the distal end gets damaged, the dinosaur will not feel much. But if the tooth gets cracked close enough to the ROOT, then there will be a lot more pain. THAT is the area that the lips cover. Indeed, the heavily elongated teeth of ceratosaurs and torvosaurs have no trace of blood vessels OR nerves within the tip. SO lips DO protect the tooth where it counts most.

>> SECOND, there ARE lipped animals with teeth protruding beyond the lips - elephants and walruses. Neither one has never in their tusks either... though both are horrible examples to compare with dinosaurs. But what about saber tooth cats? They most certainly had lips, like all cats today (or are you going to say they were lipless or beaked???)

Their canines were FAR longer than any lip. And they were to large for the lower lips to "accommodate" so they simply OVERLAPPED the lower lips outside! Now the configuration obviously was different than the one in theropods, but the same general principle applies. Many animals have the upper jaw wider than the lower so that the lower fits within it when the mouth is closed.

"Again, Nima, your support for theropod lips is based on lepidosaurs and mammals, which are not at all dinosaurian in any of their habits and the relevant biomechanics."

>> And your argument against theropod lips is based on CROCODILES, MONOTREMES, and TURTLES!!!! You want to talk biomechanics? How are the biomechanics of a croc, turtle, or platypus ANYTHING similar to a dinosaur??? Your models for liplessness are downright pathetic compared to mine. I maintain that lips are likely because unlike all your closed-niche examples, dinosaurs still had multiple uses for them.

Nima said...

I never claimed that theropods followed the biomechanics of mammals precisely, but any thinking person can see, they are a lot more similar than the biomechanics of crocs and turtles! (ehem, long erect legs, endothermy, cursorial posture????) And yet somehow you claim a monopoly on truth and bash me has having weak and poor arguments.

You have YET to produce even a single good one, I've produced at least five. What's that, foramina are irrelevant? Then lay down your crocs and ducks already. Foramina are only irrelevant if you claim they are all the same.

As we've seen in SO MANY LINKS, not all foramina are created equal! They obviously serve very different purposes in different animals! A foramen is simply a little hole in a bone! It can anchor or channel whatever structure is needed for that creature. It can be MODIFIED over millions of years for a different purpose. It does not exist in some "final Genesis form"... Need I go on?

I have already proven that liplessness, whether in beaked animals like hard-shelled turtles or non-beaked ones like crocs, is a DERIVED characteristic suited to a highly specialized lifestyle and niche. Beaks did not come first. LIPS CAME FIRST!!!

Those animals that lack lips simply lost them, and those that have them simply retained and modified the lips of their ancestors. You cannot disprove that, therefore you cannot disprove the possibility that theropods had lips. Remember, I am merely defending the viability of a lipped theropoda. YOU are the one trying to falsify it.

BTW, please try to restrain the rage from spilling over into dishonesty. It's fine to disagree with my view on this or even be upset or disturbed by opposing views, but let's understand that this is not the end of the world and we agree on MOST of the things about dinosaurs in general. That said, I will NOT tolerate another misrepresentation of my views or false statements about what I said. Lips OR beaks, not lips AND beaks.

Michael O. Erickson said...

And what about house cats? My fat orange cat has protruding "snaggle teeth" that rest OUTSIDE the lower lip, just as Nima is arguing for theropods. Simply lift the fleshy mammalian upper lip to see them. (I have, incidentally, changed my tune and agree with Nima that this is the case - the upper teeth could not "sink" into the lower lip, and the upper teeth "hugged" the lower lip.)
Seriously, Zach, this "does any lipped animal today have teeth that protrude beyond their lips?" is just flat-out ridiculous. For cripe's sake, my CAT (as in Felis catus, pussycat, common house cat) has teeth that portude beyond the lips!

Michael O. Erickson said...

"look at this mallard skull here, if you please. Notice all the foramina at the tip of the mallard's bill. Now look at this picture of a Tyrannosaurus skull in front view here. These both have very similar foramina patterns at the foremost edge of their skull. Now, using your reasoning that foramina have something to do with the presence of external oral structures, we should thus conclude that Tyarannosaurus had a beak, since ducks have beaks, and that's why the foramina are there."

Yes, but please note WHERE duck foramina are located. ONLY at the FRONT of the face. Now, the majority of a duck's beak is covered in flexible cartilage. The tip of the beak is sheathed in a keritinous "cap". The formina correspond with the keritinous part of the duck's beak. Therefore, the duck-like foramina of Tyrannosaurus rex would be indicative ONLY of a though keritinous covering (as in maybe big, tightly fixed scales or scutes) on the extreme front end of the snout of the beast, NOT a true beak.

BTW, I actually don't agree with Nima tht beaks and lips cannot co-exist. Raptors (as in dromaeosaurs, NOT modern birds of prey) had both lips AND a keritinous "proto-beak" at the front of the jaws (see Greg Paul's writings for more information on this). Raptors prove that beaks and lips REALLY CAN co-exist peacefully. But then...

"you must explain why birds do not have lips with their beaks and why turtles do not have lips with their beaks"

Uhhh.... Maybe it's because the beaks of birds and turtles occupy nearly the whole mouth line - as in they extend all the way to the back of the jaws. Turtle and bird beaks are just too extensive. There's no room for the lips anymore. Wait, were you even serious with that one? I pray not.

Michael O. Erickson said...

"Theropods did not have lips!"

Wait a second... It seems earlier there was this:

"I must strongly remind you that I never said that theropods did not have lips. What I AM saying is that we should be cautious and not get too dogmatic on the matter."

Please make up your mind, Zach.

Nima said...

Mike, you actually bring up a very good point. Greg Paul does mention a "proto-beak" in his material. Indeed, I remember the exact painting where he referred to this in his 1987 article "Restoring the Life Appearance of Dinosaurs and their relatives" or something like that.

He had a pointing of two Velociraptors, and he made reference to their "proto-beaks". The thing is, he still illustrated them with scaly faces. Yes the scales were tough and tight and flattened, but this "proto-beak" had very little in common with any modern beak. Raptors definitely were on the path to a beak, however this was only carried to its zenith by birds, and later ground based raptors like Velociraptor (which were bird uncles rather than bird ancestors) were not quite as beaky. They seem to have been in the process of LOSING the beak-like traits without ever having evolved a completely pure toothless beak... which makes sense if you buy Paul's theory that they were secondarily flightless aviformes (and actually that theory makes a LOT of sense in the first place!)

So yes there was a "proto-beak" of sorts that likely had vestigial lips (I don't think raptors had very big lips but I could be wrong). But it was no where near as "beaky" as, say, an Archaeopteryx or a Microraptor.

As for snout foramina - yes I'm with you there, they can anchor anything from beak keratin to tough skin. Any animal with some kind of reinforcement on its snout tip, will have them (it can either be rough scales like on a T.rex or Torvosaurus, OR a duck's beak which has that tooth-like reinforced stub at the tip.) Foramina have evolved in different animals to anchor all kinds of weird structures. in fact, T.rex's frontal foramina are NOT duck-like at all. They are circular, while those of a duck are more stretched and radially point to the very tip of the beak. Actually, due to the large size of its bony nostrils, T. rex doesn't even have that many of them, and they are proportionally much shallower than duck beak foramina. So there's no proof of anything like a duck's beak there.

Heck, even crocs have toughened skin in that premaxillary spot (but they also have it, with accompanying foramina, all over the head, unlike theropods!) So in all likelihood a beaked T.rex is not only unsupported but silly given what we know about the most common use of maxillary foramina. It probably just had some tough hide there for head-butting.

Nima said...

And yes, as much as I don't want to look like I'm "taking sides", I have to admit Mike has a point about the while lipless dogmatic double-talk. Make up your mind Zach.

It seems that you don't WANT theropods to have lips. It's true that theropods with permanently exposed teeth make for much more frightening movie monsters, like in Peter Jackson's King Kong remake, but that's just about all they're good for. Remember, you are always free to start your own blog and to draw theropods however you wish, with or without lips, eyes, teeth, whatever... if that's too tedious, there's always DeviantArt.

However, this blog is devoted to the science as much as the art of paleo-art. I don't draw lipped theropods because I merely prefer them that way. I do it because it's much more plausible that they had lips than lacked them. There was no reason for them to lose lips, in fact unlike crocs, lips had a lot of logical benefits for theropods. And since science never casually dismisses anything as false without addressing the burden of proof, dogmatic absolutist statements like "theropods did not have lips!" don't have much value as currency in the Paleo Kingdom unless you can either tone them down, or back them up, OR redefine through what sort of lenses you interpret the word "lips"... none of which has happened.

Zach Armstrong said...

I think from my last comment it is pretty clear I did make up my mind, theropods do not have lips. So my position changed slightly from the beginning of the debate.

Since you think I am promoting pseudo-science (which I will state for the record in my defense that I am not), go ahead and delete my comments if you want. But that won't make your view true.

You do make some good points above, but most of them are logically flawed, and I am growing weary of this debate. Furthermore what strong points you do have ("oh! I guess some turtles do have lips!) that falsify some of my lines of reasoning do not invalidate my conclusion. Having said that, it is obvious that I am not going to persuade you, not are you going to persuade me. So I guess will have to agree to disagree (or if your prefer, disagree to disagree). The evidence stacks up, in my view, to support lipless theropods. You forget that this has nothing to do with me "wanting" lipless theropods. In fact, I used to be of the opinion that they must have had lips. However, when confronted with convincing evidence that they did not have lips, I changed my mind, like a good researcher would.

Suffice to say, all your arguments for lipped theropods (i.e., lips protected the teeth, lips are basal to Amniota, foramina have something to do with external oral structure attachment (the attachement of beaks, lips, etc.)) are all proven to be wrong, or are uncertain (i.e., if the teeth stuck out of the lips, then the lips were not really needed to protect the teeth, foramina do not have anything to do with external oral structure attachment (your soft-shelled turtles do not appear to have any foramina on their skulls!), and thus you cannot make the extrapolation that foramina in basal Amniotes indicate they had lips).

Your arguments and comparisons are either inapplicable, uncertain, or just outright wrong.

On the other hand, my biomechanical arguments (if theropods had lizard lips, then they couldn't 'move' them out of the way so that the upper teeth wouldn't pierce them--lizards can't move their lips; the upper teeth fit tightly next to the dentary--there would be no room for lip muscles since the teeth were densely packed and covered most of the dentary leaving no room for lip attachment), inferring from the EPB (extant phylogenetic bracket; i.e., the closest living relatives), as well as the complete lack of necessity of theropods having lips (they have no practical usefulness), tends to make my view rather sound.

If you feel that my comments are hurtful to science, in your view, then go ahead and delete my comments. I won't be mad.

My final statement regarding this matter: Theropods did not have lips, because the current evidence supports that view. So I have to agree to disagree with your view.

Nima said...

Well if that's your final statement then we'll just have to leave it (your final statement) at that.

I have no desire to suppress information, nor am I of the view that any one person's opinion can be "hurtful" to science. Science is not some precious dogma that needs crusades, book-burnings, or an inquisition to preserve itself. The only things truly hurtful to science are censorship, punishment of research in defense of bigotry (i.e. Galileo's "trial"), and conflict of interest (i.e. Wiley Interscience and all those other greedy science-apathetic publishers that try to limit access to badly in-demand research to fill their already overstuffed pockets).

However, since I do not consider your entire side-swiping method of argument in any way scientific or valid, I will delete anything that confuses the issue with repeat ad hominem attacks (i.e. "your comments are wrong") and distortion of the statements of others, when you have not even addressed many of my main points.

On a purely theoretical level, you are trying to DISPROVE lips for theropods altogether, whereas I am saying that some had lips, and some may not have. Thus the burden of proof for an absolute statement is on you. Since we don't have facial skin impressions from any theropods, you have to prove, scientifically, that it is IMPOSSIBLE for theropod lips to function practically (i.e. the whole biomechanics angle). All I have to prove is that it's NOT impossible (i.e. they MAY or may not have had lips, different species may have had more or less lip, etc.)

And I've made it clear that given theropod jaw structure, lips are entirely possible, and judging by other NORMAL amniotes (i.e. NOT stuff with beaks, notches, or a non-cerebral reactive hunting mode in murky waters) lips may even have been LIKELY.

Yet here's the worst part of this whole mess - I constantly defend my arguments and yet you skip over the parts I most want you to read... as if selectively ignoring some my statements and distorting the rest: "Theropod lips would get ripped up because lizard lips would also get ripped up if the teeth were big!" Umm, you DO know that I never claimed theropod lips were exact carbon copies of lizards, don't you? Or don't you?

And it doesn't end there.

*You totally MISSED my lengthy explanation about crocodile behavior and lifestyle, and the MANY factors (not one or two) that make lips unfeasible for them - factors theropods never had to deal with. Why do I even bother writing this stuff if you don't respond to it? Am I writing it for my neighbor's dog?

*And then, you also dismissed the usefullness of lips ENTIRELY, totally IGNORING my theory that lips were essential for protecting the tooth roots of active hunters from damage in intra-specific head butting, specifically involving jousting with nasal ridges (as well as retaining gum moisture for a terrestrial creature, just like in BOTH lizards and mammals!)

*On top of that (yes, keep reading) I have already posted URLs to TWO rigorously accurate images that show exactly how theropod lips would function without being damaged by the teeth (both images, incidentally, are of T.rex)

You did not even address them, and I'm willing to bet you did not even look at them. Thus you CONFUSE the issue by saying that lower lips could not "get out of the way".

First, they didn't have to. As wide as the top jaw was, the lower lips would fit completely within the "enclosure" of the upper teeth. There was NO risk of snagging or impaling the lower lips. Don't believe me? Look at a T. rex skull from the front, or just GO BACK AND TYPE IN THAT SECOND URL!

Nima said...

I'll make it even easier. HERE you go.

http://2.bp.blogspot.com/_m6sVhskT_Fs/R5D4CCDH8-I/AAAAAAAABdc/NXDXv0IBTgc/s1600-h/trex_ja_gonzalez_MACN.jpg

This is rigorously based on the actual skull. So don't tell me lips can't work.

SECOND, you make this whole lip thing an issue of the lower lips being unable to "accomodate" the upper teeth like a lizard, or get out of the way. Well, I never said they did! The lower lips would be perfectly safe in their natural, un-extended position! Once again, look at the skull before you argue in contradiction to it!

I never said theropod lips functioned exactly like a lizard. I said something much simpler: "theropods most likely had lips" and you made up your own interpretations of my statement.

Neither did I say they must have been EXACTLY like lizard lips, nor did I say lizards and dinosaurs are all that similar. There is SOME convergence between their foramina AND jaw designs, but it's not perfect convergence. So you are guilty of reframing the debate into "Paleo King said theropod lips were designed EXACTLY like lizard lips so he can't be right" instead of what the debate really should have been: "Paleo King said theropods HAD lips, and lizards are just one other example of diapsids with ROUGHLY similar bone structure under the lips!"

It's not necessarily your lines of "evidence" that I have a problem with (i.e. your fervent devotion to EPB - a great example of WHY we should not throw away common sense when looking at cladistics - ever heard of "niche specialization"?). Rather, it's your unethical and deceptive methods of argument that annoy me to tears.

It would be fine if you simply presented your case for no lips and allowed me to scrutinize it without trying to misconstrue my statements and imply stuff that I never said, and then saying "you're totally WRONG". The evidence is a LOT more complex than you're letting on, and things like biomechanics and EPB (both of which you misinterpret with a very over-simplistic understanding of evolutionary biology) by no means disprove the presence of lips on theropods. I'd still disagree if you were more broad-minded in your arguments, but I'd be far more open to considering them simply out of virtue of hearing SOUND rebuttals to my view.

Honestly it doesn't matter whether whether theropods have lips or didn't. It's just that the "evidence" against ALL manner of theropod lips is very weak and superficial. However, your selective spinning and omission of my statements in such a negative fashion makes the whole debate irrelevant to me at this point.

Regardless of the validity of your initial argument, your methods of criticism and rebuttal (not to mention casually washing your hands of your own self-contradictory claims by invoking a woefully "slight" change in position from "let's be cautious and not dogmatic" to "NO LIPS!" [ROFLMAO!]) are pure POLEMIC, not science. Regardless of the honesty of your intentions, your actions have smeared my words almost beyond recognition and practically nuked your credibility on this issue.

As it is, you have not hurt science, indeed true science is free of such basic logical fallacies which you have attempted to use against me. At most you have only hurt the credibility of your opinion in the minds of more subjective and less enlightened people, and your own credibility as a debater in the eyes of the more educated.

Michael O. Erickson said...

"I used to be of the opinion that they must have had lips. However, when confronted with convincing evidence that they did not have lips,"

Huh? What? The "evidence" you have presented is NOT, in any way, shape, or form, convincing. In fact, most of it is downright PITIFUL. I would say LAUGHABLE, except it's really not that funny.

"I changed my mind, like a good researcher would."

No! You changed your mind based on BAD so-called evidence, like a BAD researcher would.

I will also add this little essay. It's called "If Foramina Have Nothing to do with Lips..":

*If foramina have nothing to do with lips, then I want to know why the row of foramina on a lizard's dentary is positioned PERCISELY where the lower lip attaches.

*If foramina have nothing to do with lips, I want to know why crocs, which don't have lips, have VERY different foramina size, shape, and placement than lizards, which DO.

*If foramina have nothing to do with lips, I want to know what they ARE for. What other purpose do they serve? If they serve no purpose, then why the heck are they there?

Until you answer ALL THREE of these quesions FOR REAL, your assertion that foramina have nothing to do with lips is just a bunch of, well, lip-flapping. What you are trying to do is get the foramina out of the way, so that you won't have to explain why theropod foramina are most similar to the foramina of lip-bearing lizards if they didn't actually have lips.

Also, that lip-bearing amphibians and soft-shelled turtles lack foramina ONLY shows that one need not posess foramina to have lips. It does NOT "prove" that foramina don't have anything to do with the lips once they (the foramina) are present! YES crocs have foramina despite a lack of lips, but croc foramina anchor though, tightly fixed skin and so are VERY different from the foramina of lip-bearing animals - a point I and Nima have been desperately trying to show you.

For the love of Pete, stop and think about it!

(no malice intended)

Nima said...

Yo Mike, cool it a little. The debate's over.

Zach just said it was his FINAL STATEMENT and he's weary of this debate.
Which means 2 things:

1. He doesn't want to debate anymore.
2. He's not changing his mind in any case

So your attack on him is out of line, IMO. We have already poked crater-sized holes in his bad research, so I think it's a bit underhanded to continue hitting him when he's already left the ring and has no intention of continuing this fight. I hope you understand that.

I don't want to seem heavy-handed here, but even though I agree that he's wrong, I don't want my fans beating the crap out of each other mercilessly. And yes, I was also trying to show him the differences in croc and theropod foramina, but don't smash him further using my name as backup. I've already done enough smashing here myself. Like I said, he's already nuked his credibility. No need to for you nuke it further.

My last comments were only intended for Zach's future contemplation, as I consider this debate over.

Foramina ARE related to lizard lips - they channel the blood vessels and nerves for lip muscles. In dinosaurs they likely did the same thing. They don't really say much about the precise dimensions of most lips, but a single STRAIGHT isolated and defined line of foramina is at the very least a strong indicator of lips. Lizards and theropods have this skull trait, crocs don't. End of story.

That being said, although you asked perfectly legitimate questions, your attack was VERY ill timed and incendiary, since Zach already gave his "final statement" and I was gracious enough to simply reprimand his debating tactics so that he might learn for the future, and I left it at that...(don't force him to get nasty... I can't have that here)...

Now I don't mean to offend you Mike, but seriously this is the time to calm the **** down. I will DELETE any further posts from either of you regarding this whole lip issue. Let the readers figure out who's got the facts right. As the Paleo King, I don't want to enter the fray of paleo-pettiness so if this lip debate blazes up like this again I will SURELY put my foot down.

SHEESH! At least one of you could talk about the actual scene or the species I put in it, and not just the damn lips!

~Peace Out.~

Michael O. Erickson said...

I guess I didn't notice that that was intended to be Zach's final comment, If I had I wouldn't have posted AT ALL. It's my fault for not reading more closely.

Done with lips. Officially.


~~~~~marks end of lips debate for all time~~~~~


Now, I'd like to ask something about the picture. I noticed that, in the torvosaur being ripped to freaking bits by the Dacentrurus, the hands appear prontated. Of late, most paleo people seem to think that theropods couldn't do that with their hands and have derided all such pictures as "bunny rabbit poses". Now, I'm pretty skeptical of that assertion, and I know Greg Paul is too. Is there similar reasoning behind your torvosaur hands? (The hands on your torvosaur drawing, that is. I'm not implying that YOU have torvosaur hands! Although you might... But then how could you hold your pencils? LOL)

Nima said...

I know that an anti-pronated view is all the rage these days. However, I think MOST theropods could still hold their hands like that. Notice that I say "could", not necessarily "did". Aside from Tyrannosaurs and weird things like Abelisaurs, I think most theropods could handle either posture. Of course their preference is impossible to know for sure.

The fact is, Allosaurs and Megalosaurs had rather flexible arms and could likely manage a wide variety of hand positions. It's only with Tyrannosaurs that the arm movement is more or less limited to the fingers facing each other. And that's a recent discovery. Jurassic predators were not so limited in their arm movement.

I notice that Greg Paul has used the new hand posture for both Tyrannosaurs and Allosauroids, so it might be more correct after all.

However, he has not updated his Torvosaurus in like manner to my knowledge, so perhaps the old posture is still valid. In either case, Torvosaurus hands/arms look more flexible and robust than Tyrannosaur hands/arms so until I see one in person, I'm pretty open to both postures as you can see in the drawing.

However, the Torvosaur getting his butt kicked is only holding one arm facing forward like that - it's the arm that got whacked by a Dacentrurus spike (you can see the skin is slashed off!). So I didn't intend for that arm to be in a natural posture, but that MIGHT also be a possible natural posture now that I thing about it. The other arm is simply semi-rotated up and outwards from its inward-clawing, "modern" position.

And if I had Torvosaur hands LOL... I would be piercing both the paper and the desk! It's interesting how despite the fact that no dinosaur had opposable thumbs, some species of sauropods (and ironically, Allosaurs too...) had highly mobile and flexible thumb claws. If not for the mass extinction, who knows if a dinosaur that COULD hold pencils may have evolved!

Zach Armstrong said...

I agree with Nima that theropods may have been able to pronate their hands from time to time. Unlike mammals, however, it appears that is was not the naturally articulated position in most theropods. Unlike the cervical vertebrae in sauropods, which have no "osteological neutral position" (ONP) that can be determined from the fossils, (fore-) limbs do apparently have a neutral osteological position. That said, they did not have to have that position all the time. True, it is likely when they were at rest, their forelimbs defaulted to this ONP (like those imprints of a resting basal theropod show).However, I have no qualms about restoring them pronated in the event of an attack of defense position.

Nima said...

Good point Zach... I would only make an exception in the case of T. rex and its closest relatives, where it now seems that the arms were limited to a fingers-facing-inwards position (interestingly this position used to be VERY popular in the old days, then it fell out of favor in the 70s, and now it's back!)

But with longer-armed predators, either position is possible - pronated for rest, grasping for attack. Except those freaky Abelisaurs, where the palms were almost turned outwards in a fixed position and the tiny arm was almost all humerus!

I've had a Tarbosaurus piece in the pipeline for I can't even remember how long... and I've been messing around with the arm posture. I know it probably couldn't do pronated when attacking, but I wonder if a Tarbosaurus could stretch its arms into a pronated position when resting...

Zach Armstrong said...

While tyrannosaurs may not have been able to pronate, as you suggest, they definitely were able to supinate. In fact, it has been suggested that the strongly muscled forearms of Tyrannosaurus could easily curl 200 kilos each!

Yes I have seen your Tarbosaurus drawing on your other website. Looks quite good, although it appears to me that the skull is too 'skinny' in places, such as where the jugal and maxilla meet. Just a suggestion to use at your discretion: you may want to add some display feathers on the forearms in the final product, as Greg Paul once did.

Derived abelisaurs probably couldn't do much with arms except move them where the humerus and scapula met. I sometimes wonder if they had proto-feather-ish "spines" like (sort of in the tradition of Tianyulong and the quill-ish feathers on cassowaries) on their arms for display. I haven't illustrated any that way, but it does remain an intriguing possibility.

Michael O. Erickson said...

"Unlike mammals, however, it appears that is was not the naturally articulated position in most theropods."

True!!! But the key word is MOST. There is one group of theropods for which the "bunny pose" MIGHT really have been the natural position.

Ornithomimes.

An interesting thing I've noticed is that articulated specimens of ornithomimes tend to show the hands pronated. In the full description of Sinornithomimus, the provided photographs show several of the specimens with fully crossed radius/ulna and pronated hands, and with all joints in FULL ARTICULATION mind you. (The "in full articulation" bit is troublesome for those who don't think ornithomimes could pronate AT ALL, and that doing so would dislocate bones.) In fact, the type specimen ofStruthiomimus, a photograph of which is in Osborn's descriptive paper, has the right hand pronated! The fact that ornithomimes seem to be preserved this way a lot, and the fact that all bones in the arm are articulated and fully in-tact when this occurs, would suggest to me that the palms-down pose was the natural posture for ornithomimes, as it is for us humans... Or at least it was a posture they assumed often enough in life that they ended up dying and getting preserved that way.

Just for giggles, here's the Struthiomimus type:

http://en.wikipedia.org/wiki/File:Struthiomimus_skeleton_jconway.jpg

Copy-paste it into your browser, of course.

Nima said...

Hey Mike, I agree with you on the ornithomimids... though I don't draw them all that often, I've seen the mounted fossils and the bones fit very well in pronated position.

And Zach, I appreciate your comments on my Tarbosaurus and I thing you have a good point on tyrannosaur arm strength and movement. I really want to finish that guy soon, but with all the sauropods I'm working on it doesn't seem likely for a while... though if I do get it done soon, it will probably be the LAST thing I ever do on cheap light printer paper.

Ever since "Deadly Stalkers of a Crystal Sea" it's going to be textured HEAVY paper all the way. W00t w00t!

Though I doubt I'll be adding arm feathers to Tarbosaurus. IMO, Greg Paul's Tarbosaurus vs. Therizinosaurus piece looked better before he gave the Tarbosauruses arm feathers. It was the Therizonisaurs who really needed them...

I doubt adult tyrannosaurs of any large species has feathers... not that I have anything against feathers, but with the arms so reduced, I don't think they were much good as a display device period. Creatures with display feathers on their arms would ideally be things like Oviraptor that have proportionally big arms.

For the same reason I also prefer naked-armed Abelisaurs (though also they are even less likely to have feathers because they are of ceratosaur and NOT tetanuran/coelurosaur lineage). I am aware of Tiyanulong and its filaments, and indeed some other dinosaurs may have had them. But these are not fully developed feathers - they are perhaps a VERY early form of proto-feathers which other species could easily have lost... and in any case Tiyanulong was small... nothing really big has ever been found with feathers.

BTW I'm not in ANY way supporting the notion that no dinosaur has feathers or that birds came from a non-dinosaur ancestor (i.e. all that BAND nonsense guys like Feduccia stake their careers on). But I don't consider Tiyanulong's "feathers" to be anything on the same level as what you find on Microraptor, for example, nor do I think most dinosaurs necessarily retained these basal filaments (if indeed they are basal to Dinosauria). And I doubt that big, short-armed predators like Abelisaurs or Tyrannosaurs had much use for feathers as adults, either for insulation or display.

That makes little difference to me though, because in the end I still consider them all warm-blooded. Interestingly Greg Paul revised the arms of Tarbosaurus with feathers, and the arms of T. rex without.

Michael O. Erickson said...

Well since we're discussing all manner of things here, I'd like to know what YOU (Nima) think of Holliday and Witmer's assertion dinosaurs lacked the cranial kinesis that Bakker had proposed for theropods in the '80s. Now, I have some very strong feelings about the paper, but I'd like to see your views before I chime in myself.

Michael O. Erickson said...

Oh, and one other thing: How come none of your sauropods (including the Lusotitans in this particular pic) have dermal spikes?

Nima said...

Cranial kinesis? WHOA, you got me on that one!

If I'm not mistaken, that refers to the ability of the upper jaw to splay and widen relative to the braincase... I'm not too clear on this one, but I think Bakker has done great research and has rarely been mistaken on any serious issues.

So far I'm inclining towards Bakker but don't take that as an endorsement because I'm not altogether familiar with the issue. But I do think that Witmer's conclusions often are a bit off. Though I can't let that TOTALLY prejudice my opinions... I'm interested in knowing the details!

As for the dermal spikes... I had a pretty long discussion about them with Zach on DeviantART... I don't think Brachiosaurs in particular had dermal spikes. Diplodocids did, yes, but they have never been found on Macronarians. It may be that they are a feature found only in Diplodocoidea, but the jury's still out on that one. If someone DOES find a Brachiosaur with associated dermal spines, I will of course seriously consider revising my drawings. But with the Lusotitans so far away and two of them facing forward, giving them spines is a pretty moot point in any case, as you won't see them.

I know Greg Paul and others draw the spikes on every sauropod, but I'm not convinced. Basal sauropods don't seem to have them either (Raul Martin omits them on macronarian species as well, and almost nobody puts them on titanosaurs). Though again, I'm open to changing my restorations if new evidence proving the presence of Brachiosaur spikes turns up. It's a lot easier to draw the spikes than erase them... though if you are a digital nut, that's not too much of a problem.

Nima said...

BTW, I haven't really drawn that many sauropods since I started this blog, so I assume you're referring to my old stuff on DeviantART or my website... some of those are a bit inaccurate in my view now, but not for lack of spikes... (keep in mind that a lot of those older drawings were done when I was 12 or 13).

Don't worry, there WILL be sauropods coming. And SOME of them might have spikes.

Michael O. Erickson said...

"Cranial kinesis? WHOA, you got me on that one!

If I'm not mistaken, that refers to the ability of the upper jaw to splay and widen relative to the braincase...
"

You are correct, sir. Dead on.

Zachary said...

Cranial kinesis doesn't mean THAT, it means the ability of bones in the skull to move against each other. Holliday & Witmer just published a paper on the topic, concluding that our ideas about cranial kinesis in dinosaurs is severely overexaggerated, and may not have occurred at all.

Second: I didn't read every post, so I don't know if you fellas ever came to a conclusion about crocs losing their lips, but it probably happened because they evolved such highly-developed electrosensory structures on the snout. Fleshy lips or epidermal structures would, supposedly, blunt their effectiveness.

Nima said...

Well I have no intention of re-igniting the lips debate, but as for croc lips, yes that makes sense. Crocs do have some very sensitive "ampullae" on their snout (though they evolved independently of the ones sharks have) for detecting electrical pulses from animals.

Actually, I suspect that a large number of the pits and "foramina" on their faces are devoted to that very purpose. This indeed is a very derived condition which no other "reptile" shares, to my knowledge. And it's actually a very good reason for crocodile lip loss. As with other reasons, lips for a croc would simply get in the way of things...

dkrentz said...

I just read this above.

"Come to think of it, in the Disney movie "Dinosaur", the Iguanodons had lips over their beaks! When will those hacks stop trying to make animals and their facial expressions look more human?! Not to mention injecting their Carnotauruses with ridiculous amounts of growth hormone, turning Brachiosaurus into a pathetic whiny weakling, and giving the old male Iguanodons an oddly ceratosaurian nasal bump!"

So, being the hack that designed those dinosaurs for that movie I feel I need to defend myself. I lost sleep over doing those things to dinosaurs and putting lips on Iguanodons was a terrible day for me.
I worried and stewed over the effect it would have on science, children...blah blah blah. Nearly twenty years later I'm happy to say that it had NO effect at ALL. It was a Disney movie. And not a good one. I designed characters, not dinosaurs. Period. Some of the herd characters I could stick to the facts with because they did not need to perform. For every dinosaur in that movie I gathered as much research as possible and did my homework. I went to the collections rooms, handled the bones, read journals, went to SVPs etc. I have gone to many a science convention with a slide show explaining how and why many of the decisions were made. The one thing I learned from the whole experience is that movies are movies and science is science. I take both jobs very seriously, but to get the people signing my paychecks (in the movie world) to actually care about science is a continued losing battle. I'll still try and imbue every design I do with science, but my expectation of that making a difference to the movie or the people watching it is very low. I will continue to use science as apart of my movie work for my own education. The sad thing is that even when I do work for paleontologists paleo-art, or whatever its called, is almost always a necessary evil to them. I doubt most Paleontologists could name four or five paleo-artists by heart. I've talked to Scott Hartman at length about that.

I keep looking at this post and wondering if I should even send it. Like I mentioned, its been over 20 years since I worked on that film so what is the point. As I write this I realized why this is bugging me.

Two days ago I put that movie on the DVD player and watched it with my 18 month old son for the first time. His eyes were as big a saucers; he was breathless. I imagine thats what I looked like when I saw King Kong for the first time. That movie ignited a love for dinosaurs and ultimately for a respect for the science for many of us. Today when he was taking a bath I saw that he brought in a little Ouranosaurus toy with him. He said "dio-sah". My heart melted and I felt vindicated for putting lips on Iguanodons.

In short I don't want this to seem like I'm hypersensitive. I just want to say my piece.

Please keep on drawing and be passionate.

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