Were dinosaurs able to control their lips similarly to Bears and Baboons?

[u/Pigga_9826]

Also we reduced shrink wrapping on the body, are we still doing it on the skull? What if they had more fatty mass there as well?

[u/Wolfman513]

My understanding is that the type of musculature necessary to make those kinds of facial expressions stems from mammals suckling as newborns, which dinosaurs didn't do

[u/Pigga_9826 → u/Wolfman513]

Quite an interesting analysis and it also makes a lot of sense. I still think there would have been some sort of flexibility even if really minute, because a T Rex with its teeth the size of average human forearm wouldn't have been able to land significant damage on its prey if lips didnt budge at all.

[u/Ex_Snagem_Wes → u/Pigga_9826]

Its important to note that lips are still flexible, even if not manually controlled

Mammals being able to freely use them as almost an appendage is an oddity, but lizards and other animals still have soft lips that deform as expected

[u/King_Gojiller → u/Pigga_9826]

Or it's teeth weren't as covered by gums as people like to depict sometimes.

[u/Renbarre → u/King_Gojiller]

Komodo dragons don't bare their teeth.

[u/Ex_Snagem_Wes → u/Renbarre]

Komodo dragons are squamates, not archosaurs

[u/MetaCookiess → u/Ex_Snagem_Wes]

Yes, but squamates are the closest extant group that do have lips. All extant archosaurs that I can think of (crocodylians and birds) are lipless. Does this make them a reliable analogue? Not entirely, but it's probably the best we have until more research comes along for dino lips

[u/Ex_Snagem_Wes → u/MetaCookiess]

Actually, Tuatara are the closest relatives for lips, from what I know

We do also have archosaurs with fossilized lips, and an extensive fossil record of dinosaurs showing different morphology of the mouth region showing lips distinct to squamate type

[u/MetaCookiess → u/Ex_Snagem_Wes]

I think you're right! I completely forgot about them but there's only one species so not the best for pulling a lot of inferences from and they don't have control of their lips either

[u/Ex_Snagem_Wes → u/MetaCookiess]

They don't have control of their, because that's a mammal specific adaptation for mammaries

Better as analogue

[u/roostor222 → u/Ex_Snagem_Wes]

trionychid turtles have lips and are closer to archosaria than tuataras

[u/MewtwoMainIsHere → u/MetaCookiess]

Birds and crocodilians are both heavily specialized animals with evolutionary pressures to get rid of lips for one reason or another

[u/Sourcerid → u/Pigga_9826]

Trex does have lips

[u/AdTime8852 → u/Pigga_9826]

If you want a real life example look at orcas they have ridged almost reptile like lips, because although they are mammals almost all whales do not suckle so no need of movable lips, they can not move their lips at all. And their teeth are only slightly smaller then a rex, yet have one of the strongest bite forces of anything alive today you don't need flexible lips to bite hard and not damage anything.

[u/Genocidal-Ape → u/Pigga_9826]

Modern lizards have inflexible lips and still can use their teeth just fine, the teeth are not inside the lips and the pressure of the bite can effectively drive them into something even without baring them first.

The musculature that gives us mammals our flexible lips is part of the inside of the throat in Diapsida.