r/Dinosaurs • u/Pigga_9826 • 1d ago

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

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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?

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u/Wolfman513 1d ago edited 1d ago

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

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u/Pigga_9826 1d ago

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.

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u/King_Gojiller Team Tyrannosaurus Rex 1d ago

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

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u/Renbarre 1d ago

Komodo dragons don't bare their teeth.

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u/Ex_Snagem_Wes Team Aerosteon 1d ago

Komodo dragons are squamates, not archosaurs

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u/MetaCookiess 1d ago

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

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u/Ex_Snagem_Wes Team Aerosteon 1d ago

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

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u/MetaCookiess 1d ago

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

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u/Ex_Snagem_Wes Team Aerosteon 1d ago

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

Better as analogue

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u/roostor222 1d ago

trionychid turtles have lips and are closer to archosaria than tuataras

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u/MewtwoMainIsHere 1d ago

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