Grinnin' like a dinosaur!

[sid]

Inspired by the post about theropods' lips on the "Bite Stuff" blog, i decided to open this thread to talk with hyou about something that always bugged me since i started again to seriously draw dinosaurs; maybe it is a stupid question, but here it is:

Ornitischian dinosaurs are (almost) always restored with cheeks that cover the teeth; fine, i don't see anything wrong with it... But what about saurischians? In sauropods and most of all in theropods the line of the mouth was visible up to the back of the skull with a sort of internal "cheek" as in crocs (and most restorations, see for example the JP Rex), or is there a possibilty that even the meat-eaters had skin covering the back of their mouth (like many modern carnivores like wolves, lions, cats, etc)?

Take for example Matteo Bacchin amazing theropods; he restores them with an external covering, and it would work if we don't take into account that some theropods (tyrannosaurids for example) had a very pronounced jugal ridges and in some cases even hornlets... Or these element would not debunk the idea of an external "curtain" of skin?
Soooo... What do ya think?

[Griffin]

Well ornithiscians are restored with cheeks because their skulls suggest it. Sauriscians dont really have dentition that would suggest they had cheeks of any sort so the best guess would be to reconstruct them like other known reptiles.

[sid]

Yeah, but do you think that, for example, theropods had their jugals and surangulars covered by skin, thus forming a sort of "false cheek" as in many birds and predatory mammal, or the connection was more like in crocs (where the connective tissue is present but it's more internal and the line of the mouth is completely visible)?
Or it likely depended from species to species?

[Griffin]

I don't know what you mean with birds. Can you give me an example? I wouldn't assume it was the same as in any sort of mammal really.

[sid]

Sorry to not be clear... What i meant when i was talkin' about "bird mouths" i was thinking of something like that:

upload.wikimedia.org/wikipedia/commons/1/1c/Ring-billed_Gull_-_head.jpg


See? The line of the mouth (or beak, in this case) stops right below the eyes, while in this case:


upload.wikimedia.org/wikipedia/commons/c/ca/Leistenkrokodil.jpg

the ridges of the jugal and the surangular are pretty evident; so, back to the first question, what do you think it was the typical appeaarance of a theropod (or a sauropod, for that matter) mouth? Croc-like, bird-like, or something in between?
And bear in mind i'm talking mainly about the general outline, not the possibility they had or not lips

[Griffin]

Oh I see. Hmm I don't really know. I have always reconstructed them the same as a croc though.

[sid]

Oct 4, 2011 21:40:59 GMT Griffin said:

Oh I see. Hmm I don't really know. I have always reconstructed them the same as a croc though.

Actually i used to draw 'em that way too... But now i'm more inclined to think that MAYBE not all theropods had a "croc-like" mouth outline... Take tyrannosaurids for example: their jugals have very pronounced ridges and rugosities that maybe housed keratinous hornlets plus, in frontal view (and that's especially evident in T.rex) the back of the upper skull is slightly wider than the mandibles, like crocs. Ergo, it could be said that probably they had a mouth outline more similar to the aforementioned crocs. The same can be applied to ceratosaurs and abelisaurs, but what can be said about allosaurids, spinosaurids and all those small to medium sized theropods, plus the sauropods? Their jugals all seem to lack rugosities or pronounced ridges, so maybe the outline was more bird-like (like it more than probably was in feathered dinosaurs).

Or maybe i'm just too much tired and i'm just mumbling nonsense...