We've seen different snouts, different beak shapes, different frill stud counts, different frill shapes, different squamosal shapes, and different horn shapes in the biggest and most mature specimens.

But guess what we haven't seen? Different details IN the horns.

This is the skull MOR 1122 - one of the two huge "boss-nosed" Torosaurus skulls, both of which are in Jack Horner's own Museum of the Rockies.

See anything odd about the brow horns? Anything sidesplitting that doesn't appear in any Triceratops?

Those deep chasms in the horns are real. Only the horn tips and the beak have been restored.

Lets look at some well-known Triceratops skulls:

Cast of T. prorsus holotype at the NHM, London

The "Kelsey" Triceratops - a very old individual of T. horridus.

the very mature TMP T. prorsus skull - no epoccipitals left here!

The "Homer" skull, another elderly T. horridus - seriously who picks these names?

couple of young T. prorsus skulls at Seckenberg museum

The Torrington skull - old individual, appears to be T. horridus, NOT the same skull as "T. eurycephalus".

Dakota dinosaur museum T. prorsus skull.

Another, younger T. prorsus - there is a slight groove that expands at the horn tip, but no huge chasm in the midshaft of the horn. Additionally, this short-faced skull is one of the LEAST Torosaurus-like out of all the Triceratops specimens known.

NONE of them have those deep chasms you find in Torosaurus.

So now we can see that not only do the horns of most Torosaurus skulls have a different shape than one would expect for a mature Triceratops, but even the anchoring surfaces of the bone cores that held the horn sheaths in place were different - namely that Torosaurus had deep clefts in the bone cores that the outer sheath would have hooked into - something completely absent in Triceratops.

Now not necessarily every Torosaurus would have had these natural gashes, but the ones we have complete or near-complete horns for, do show them. The odd thing is, the most mature Triceratops skulls don't have such gashes in the horns, not even smaller ones.