LIVE BLOGGING: Post # 6: rearing Omeisaurus

Posted by Nima On Friday, October 23, 2009 23 comments

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Ok, here's the most recent update:



I added two more Omeisaurus, one of which is rearing to eat higher branches.
I think I got the neck a bit TOO thin on that one, but I'll iron it out on the next update.
Also the dynamics of this graceful creature as it walked must have been truly marvelous, considering that most sauropods are usually depicted (incorrectly) as super-obese, ponderous hulks just barely plodding along at snail pace. This guy was the sports car model, while titanosaurs were the bulky "SUVs" of sauropod-dom. Also if you look closely notice the big thumb claws. There were a lot of sauropods that had them, but Omeisaurus and its kin had possibly the most oversized ones ever known. I can only guess that this was a very useful active defense for a creature that was not quite massive enough to rely on size alone as a deterrent for the packs of big predators of the day.


Also I added more trees and more background to the Shunosaurus area, with one on the hills just behind. It's shaping up very well so far, IMO. The most tedious part will be the trees.

23 comments:

Zachary said...

Okay. Nitpicky comment here. The thing already has a stupidly-long neck. I pose the same question for the brachiosaur in Jurassic Park: why bother rearing up?

Nima said...

Because the top of that tree is the tastiest part, LOL.

No, really.

These guys didn't have to rear most of the time. But consider if they just felt like eating from a tree that had all the really high branches missing (probably eaten by other sauropods).

Rearing has two purposes - feeding even higher and fighting.

Macronarians probably didn't rear as much as diplodocids (and I'm sure I'll get more nitpicky comments for considering Omeisaurus a macronarian rather than just a basal eusauropod) but they could still rear.

As for Brachiosaurus in Jurassic park - it (or rather, she, since they were all female to begin with) was just putting on a show for the camera. That is not natural behavior for any animal - just showing off right when some humans started staring - very odd considering she was definitely able to reach the leaves without rearing.

So I guess Spielberg just though that humans are so important that even 40-foot tall dinosaurs that have been dead for 150 million years will eagerly do tricks to impress them! I almost expected him to have her standing on one foot like a circus elephant, but even Hollywood has limits on its own fakeness. That Brachiosaurus was also WAY overbulked, but that's another issue for another time.

The Crap Blog Detective said...

stop littering the world with your so called unique stamps.

Michael O. Erickson said...

I like the rearing Omeisaurus, nice touch! It's all really coming together beautifully.

But I disagree with your comment that the Jurassic Park Brachiosaurus was WAY overbulked. I simply don't think it was. I know sauropods were NOT obese, plodding reptilian hulks moving along at speeds that would embarass turtles, but they were also NOT stick legged, skinny-necked, emaciated, multi-ton ballerinas. Sauropods were nimble, quick, yet heavy-duty, WELL-MUSCLED and solid biological machines. The fact is, all sauropods had muscle insertion areas on their bones (including those cnemial crests) that were FAR more well-developed than those of elephants scaled up to the same size. Perhaps Speilberg's Brachiosaurus really WAS too chubby, but Greg Paul's version commits the exact same crime - only in reverse. His is too skinny.

But this little disagreement aside, I really want to reinforce that this pic is looking freakin' awesome, and I can't wait to see it finished.

Michael O. Erickson said...

Oh, and Crap Blog Detective...

stop littering great blogs like Nima's with nonsense like your comment.

Michael O. Erickson said...

In response to your comment on the other post Nima:

The more I look at Sibbick's Omeisaurus, the more I agree that, although it's a beautiful drawing, it doesn't do justice to the actual creature.

"Josef Moravec is probably the most popular example. Even his newest stuff is straight out of Burian and Knight, which in the 21st century is rather sad."

Okay, now you're being too KIND! Not only are Josef Moravec's paintings straight out of Burian and Knight, some are DIRECT copy-cats of Burian paintings! Seriously, there's a Corythosaurus painting on his website that is lifted right from an ink sketch of Burian's, and then there's his Brontotherium that is just Burian's painting of the same animal but with an somewhat altered backround.

What's worse is that Moravec doesn't even acknowledge any of this. He instead states that Burian's work is "an important influence" to him.

"Important Influence" indeed!!

Nima said...

I do agree with you that sauropods should neither be too skinny or too fat. However, the cnemial crest argument should be analyzed more carefully. Cnemial crests anchored primarily shin muscles, and how much they stick out relative to the main shaft of the tibia is a generally accepted good measure of how suited the animal was for running.

Graviportal animals like sauropods had a larger cnemial crest than elephants for a rather simple reason - elephants barely have one at all! They have a patella on the other hand, which sauropods lack. The lack of a substantial cnemial crest means elephants have a bit of a "lazy swagger" to their walk (this is easy to see when they stop to grab some acacia leaves with their trunk).

Sauropods had a lot more weight to support and also had to move that mass at an acceptably high speed to get to the next clearing/water hole/nesting site. So a large cnemial crest makes perfect sense for them - however, the SHAPE and RELATIVE size of the crest is more important than the raw size.

Sauropod cnemial crests are proportionally bigger than those of elephants, but they are proportionally a LOT smaller and flatter than those of a T. rex or a Triceratops - why? Because those animals were fast runners with cursorial legs. Get to the size of a Brachiosaurus, and having honkin' big T.rex like cnemial crests isn't going to do you any good. There is definitely an upper limit to cursorial and even semi-cursorial animals.

The other fact I want to point out is that in ANY animal with cnemial crests, the shin muscles do NOT bulk out very far beyond the crest. They do bulge somewhat in large theropods and ceratopsians, but the shin muscles are still a lot "flatter" than the calf muscles.

In graviportal sauropods, they would have been lower and flatter still. So IMO, Greg Paul is not making them too skinny. He's only extending the muscles as far as the crest extends - which makes perfect sense. Making the legs any thicker implies that the extra mass is seasonal fat, not muscle. And I'll admit he doesn't do his silhouettes that way. He draws them "lean" as they would be at the end of the dry season, to show their muscular anatomy.

Now, were there exceptionally muscular Charles Atlas sauropods? Perhaps. But with animals that needed fairly simple light muscles to move their graviportal limbs, that would be more the exception than the rule. They were not covered in bulging muscles like, say, ceratopsids.

Bakker's sauropods looks like prime wet-season sauropods. Every single time. It's just preference, I guess.

My drawing here is the same way is the same scenario as most of Greg Paul's stuff - the wet season has JUST begun, the sauropods are still rather thin. Maybe I'm exaggerating their thinness even beyond Greg Paul level, but also considering this is a miniature, it's a bit harder to get ideal proportions.

Nima said...

As for "crap blog detective" (whose own blog is the crappiest of them all!), it's laughable that there are so many no-name losers on the internet who contribute nothing positive but merely bash people they have no clue about... the lummox should really get a life. And learn a trade. And perhaps make a blog that's about something more productive than complaining about other people's blogs. Anyone who tries to censor science and the spread of scientific knowledge and ideas is a fascist.

I'll let this follytician's drivel-filled excuse for a comment stay here for now, so everyone can click the link to his profile and blog and see how he's most likely succeeded at nothing in life other than making a total ass out of nobody but himself ;)

Nima said...

BTW I should do a post on Moravec one of these days. I'm not one for bashing artists, but when they so blatantly rip off the EXACT work of another artist, down to the exact color and style and pose and everything with no credit given... that deserves to be addressed.

Not to mention the fact that Moravec (or at least his website) has an ego bigger than an Amphicoelias fragillimus! In praise of his own long-outdated work (which no paleontologist to my knowledge has endorsed or even commented on with DML and such things), his site has such adulations as:

<<... Few other artists have re-created this world of great dinosaurs withsuch attention to detail, depth of feeling, or profound sense of history>>

ACTUALLY, many artists have easily surpassed him, and his paintings are full of basic anatomical errors than even contradict the SKELETONS! And they're ANYTHING but detailed. EGO TRIP!

<<...Learn more about this Amazing Artist>>

Amazing? Does any artist say this about himself unless he's making a sales pitch? And even then... a little modesty would help when you're basically regurgitating pre-baby boomer era paintings! DOUBLE EGO TRIP!


<<...A kind of child prodigy, Josef began drawing dinosaurs, however rudimentary, at the age of three, and created his first oil painting when he was ten years old>>

A KIND of child prodigy? What's that? Either he was a prodigy or not. Either he was freakishly good at dinosaur art, or he wasn't. I know I was - but in my case I actually have some of my old drawings up on my website to prove it! And I don't parade the epithet on my site as Moravec does. But let's put that aside.

He was "kind of a child prodigy". Fine. Maybe he was. Whatever that means. I'm not sure WHAT it means LOL...

<<...Although formally schooled in graphics, his artistic sensibilities led him to appreciate and study the "Old Masters" such as Leonardo da Vinci, E. Pieter Brugel and Rembrandt.>>

Yes, all fine and good. But the "old masters" of paleo-art, unlike old masters of human figure art, faced the problem that their reconstructions were by necessity largely speculative, and new evidence could debunk them at any time.

<<...In the field of paleontology, Josef's most important influence has been Czech paleoartist Zdenek Burian, whom he admired and studied from a very young age. And like Burian, Josef has always strived to show us the prehistoric world as it really was, through the eyes of paleontologists.However, Josef Moravec's unique vision of prehistoric life is not simply the inspired imaginings of gifted artists but the thoughtful and intelligent result of his education in paleontology.>>

In the eyes of WHICH paleontologists? Basically his "paleontology" education was a mere self-study of one long-ago artist - Burian. Is this "education in paleontology"? He simply rips off Burian. It's all an homage to that one man. Is Burian God? Why have no other artists had an influence on Moravac's Burian-ripoff paintings? Of course when you have only one influence you do tend to rip him off subconsciously.

His site says nothing about whether he's ever consulted with paleontologists or even met with them (I can at least claim to have met one, as you can read on my ArtEvolved profile - and again I'm far younger than Moravec).

Traumador said...

It is progressing nicely this piece.

I love the panorama style you're going for! (I'm obsessed with taking them in my photography, so it is cool to see them in drawing form too ;p)

Can I humbly request a crocodile or some sort of non dinosaur in the stream... For partially a sense of scale, and just to add some diversity of life to the scene.

As for this Crap Blog Detective guy, I think the fact he gets off feeling important and cool by tearing apart little kids' blogs summarizes all that is wrong with him. Wow what a big smart guy you are, terrorizing young kids for writing and expressing themselves at such a formative age!

Nima said...

I don't know which little kids those are... but yeah, that guy is, to quote Casanova, "an idiot of the first water". "Dog Crap Defective" is most likely a nobody who has nothing useful to offer the world and nothing better to do than spew ignorance and verbal diarrhea on the web.

As for a croc - I will put one in, and ironically, it was in the original plans (in that cheesy darkened sketch I posted a while back). But I will put it in the lake and not those little streams because the average Jurassic croc would have stayed clear of huge sauropods. Cretaceous mega-crocs are a different story.

BTW I like panoramas a lot but usually it's hard to fit them on a 8.5 x 11 sheet. If only this heavy paper came in 11 x 17...

Michael O. Erickson said...

"He's only extending the muscles as far as the crest extends - which makes perfect sense."

That's the part I'm getting at. He actually DOESN'T extend the the muscles out to the very boundry of the crest - he leaves the crest JUTTING OUT. Take a look at his Giraffatitan skeletal:

http://www.wisegorilla.com/images/dinosaurs/brachiosaurus3.jpg

See how the shin muscles fallow exactly the edge of the shin bone, leaving that bump (the cnemial crest) sticking out? That's what I'm talking about. Filling that space with muscles (as it should be) makes the leg thicker, like a Bakker drawing (though not quite as fat as Speilberg's version).

As for what you said about Josef Moravec and Dog Crap Detective, Amen.

Michael O. Erickson said...

I just don't beleive that, even during the lean season, the cnemial crest would have jutted out like that. There just is no modern animal that walks around with a cnemial crest that pokes out so far you could hook a doghnut on it. The shin muscles extend as far out as the cnemial crest does in all animals, including sauropods - period.

Nima said...

Greg Paul does make the shin muscles lean on Giraffatitan and other sauropods. However, I believe he's got a good reason for doing that.

Shin muscles were very important for fast-running dinosaurs because they had highly mobile ankles and their metatarsals moved as a segment. The shin muscles were big in these animals in order to quickly lift the metatarsals and thus the feet up for fast running, while calf muscles pulled as the leg extended to complete the stride.

Sauropods were very graviportal and so they needed only minimal shin muscles. Heck, humans can run and we barely have shin muscles at all! The other consideration to make is that the cnemial crest could have become enlarged as it did in sauropods to help them "kneel" to sleep or for other reasons. Elephants can do this but only with great difficulty. So many tons of weight for sauropods could explain why the cnemial crest was large and FLAT-FRONTED and not large and pointed or shelf-like as in cursorial dinosaurs.

Just a thought.

In any case, even Scott Hartman, who draws the shin muscles extending ALL the way out to the crest, ends up with pretty slim sauropods not THAT different from Greg Paul's. In fact his rigorous Mamenchisaurus skeletal (which is not all THAT different from Omeisaurus) has leg bones of almost uniform thickness, barely any "jutting out" of the cnemial crest, and very little room for shin muscles anyway.

Most sauropod leg movement in any case was controlled by the thigh muscles. Since their metatarsals were short and not used for running, and depending on who you ask, were practically immobile, big shin muscles were not really too terribly necessary for these guys.

Michael O. Erickson said...

What you've said is quite true. However, I would like to point out that the reason Scott Hartman's sauropods have skinny legs, despite the fact that he extends the shin muscles out to the edge of the crest, is because he keeps the main bulk of the shin and calf muscles rather high up on the lower leg - a "drumstick" of sorts. And I'm not really buying it. Many dinosaurs (theropods to the extreme) had drumsticks, but that's because the feet were birdlike and so were operated by tendons attahed to birdlike leg muscles. Sauropod feet were the exact opposite of birdlike (including being nearly immobile), so I think it is quite wrong to show a sauropod with drumsticks.

Scott also makes the ankle very lightly muscled, in keeping with the drumstick model. But even Greg Paul admits the ankle joint was buried.

So to sum my arguments up, Greg Paul says of sauropods: "In fact, the shin was hardly muscled at all, as in humans and elephants." Basically what I'm saying is that this statement is falsified by the fact that sauropods have cnemial crests, and thus by default shin muscles, that are far more well developed than those of humans and elephants.

Although there is, of course, no denying that there is a degree of personal preference assosiated with this as well - with mine being Bakkerian sauropods that are fat yet nimble, bulky yet agile.

But some sauropods WERE thinner than others - you are correct regarding Omeisaurus being a "Sports Car Model", and it DOES come out as one even when you substitute a Paulian model for a Bakkerian one.

Michael O. Erickson said...

Oops, that last line should be "Substitute a Bakkerian model for a Paulian one."

Michael O. Erickson said...

Or did I word it right the first time? I'm confused!

Nima said...

Hmmm... you could either say "swap a Paulian model for a Bakkerian one"...

or...

"substitute a Bakkerian model for a Paulian one".

I think that's how it goes, if you mean discarding Paulian and embracing Bakkerian (I don't know if the english spoken in your area works a bit differently)... And yes, it would still come out on the thin side with the Bakkerian model.

---------------

I don't really see "drumstick" on any of Hartman's sauropods except perhaps Giraffatitan - but I tend to disagree with how he did the feet on that one. Tibia proportions are also a bit off.

But his Mamenchisaurus isn't really "drumstick-legged" - it just has small feet and ankles. It has an almost straight-edged shin muscle from its cnemial crest all the way to the front of the Australagus. Are you suggesting that the front of the foot was buried deep in shin muscles, even down to the phalanges? I find that highly unlikely, since an immobile ankle wouldn't NEED big shin muscles anyway, and to top it off, the toes have no muscle scars on the top surface.

When I read your comment, what you SEEM to be saying is: "Scott Hartman is wrong because he draws the legs too thin at the bottom like drumsticks of a cursorial dinosaur" but at the same time you claim "it needs big bulging shin muscles that attach to the metatarsals like a cursorial dinosaur!"

Sorry but that sounds pretty odd to my ears and if that's what you meant to say, then I just don't see the logic behind that.

Nima said...

If that's not what you mean, then please clarify... this all sounds very interesting :)

Michael O. Erickson said...

Oh no, that's not what I mean at all! But it's very hard to explain this stuff without pictures. Can I send you an email with some musculoskeletal diagrams and stuff so I can show you what I mean?

Michael O. Erickson said...

Well, I just went ahead and sent the email. Check your inbox. :)

Nima said...

I checked my inbox, you made a very good sketch (though it is SO traced, LOL!) but it's all good.

It's a good illustration of the three different models. And I'd have to say, your "Bakkerian" model is WAAAAY to plump for my taste, and I don't really think muscles were laid on that way... but each to his own. I like Greg Paul's version a lot more than Scott Hartman's, Hartman makes the heel pad too small.

I think that the cnemial crest might have enlarged in sauropods for reasons OTHER than anchoring shin muscles. For one thing, why was it so deep and flat-fronted in sauropods? That pattern does not appear in any other group. I think it's a unique adaptation. Perhaps the large front surface anchored very tough skin like the callosities camels develop, for kneeling down to rest. The other issues is, if sauropods had big shin muscles as per your model, what on earth would they ever use them for?

Shin muscles are used for lifting up the metatarsal segment in cursorial animals. Do graviportal animals with immobile ankles need them? Not so much.

Even human shins are very lightly muscled despite the fact that human ankles/metatarsals are anything but immobile. So in my view the enlargement of the crest may have had other driving purposes.

Michael O. Erickson said...

"That pattern does not appear in any other group."

It appears in stegosaurs... And that probably aids your "for kneeling" theory, considering stegosaurs were graviportal and elephantine too...

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