How do they know about dinosaur lips?

"Theropod dinosaur facial reconstruction and the importance of soft tissues in paleobiology." Cullen et al., Science 2023

[Eyemknotthe]

They found the T-Rex lip balm fossilized in the rocks next to the T-Rex arms. That’s why the lips were so dry, the T-Rex couldn’t reach its lips with those short arms to apply the balm. Heartbreaking. But that’s how they learned the T-Rex had lips.

[BryanLee]

It's amazing how much the classic image of the T. rex has been updated by new data. No longer tail-dragging scaly lizard monsters but forward-leaning, feathered, likely vibrantly colored, and now luscious lips! 💋

[DeadpoolE]

It's a bit more than that. Other than the cross section of the tooth, they also noticed the holes along the jawline on many dinosaurs and figured that they housed nerves and musculature. They then compared these skulls to those of lizards and figured that dinosaurs may have independently evolved these extraoral features, or at the very least such a condition may have been ancestral in the Archosaurian line.

[gimpytheimp]

There's also the fact that the skull around the teeth has holes for attachments to lip muscles you see on other animals

[AceSpades]

There’s a few other reasons for many dinos having lips. But it’s also important to note that it wouldn’t be like mammal lips where they could snarl or more them at all. They’d be more like lizards lips. And then there’s the ones that had beaks instead or like spinosaurus may have been more like a croc

[kylecedrickgraciano]

As a reptile owner most reptile have "lips" they don't have outside teeth like an alligator or crocodile.

[spiderzvow]

All i can see is that cat going to town grooming in the background

[Joesteroven]

They had lips. Teeth can dry out and become brittle when exposed to air. This isn’t a problem for the water-bound crocodilians. Their skulls are also heavily pitted with channels for nerves and blood vessels and anchor points for muscles along the ridge about the teeth where lips would attach. They had no use of their arms so maybe their lips were a lot more important than we could imagine.

[FaeMab]

i have a pet argentinian tegu
and i once bred asian water monitors
their teeth are both protected inside "lips"
their teeth almost retract(been bit a few times)
their anatomy is amazing and fossils can only tell us so much 1

[Dantethedinodude]

It makes sense because alligator spend most of their time in the water which moisturizes their mouth and protects the teeth, but T-Rex wouldn’t have been in a watery environment, so T-Rex would’ve needed lips to keep the teeth moisturized

[cesaraugustoojeda]

I love the cat in the background grooming itself

[switchprocontrollersplatoo]

Honestly giving it lips just makes it even more terrifying. Makes it look even more like a monster for some reason

[mcvenne]

Everytime they find new info, the t-rex becomes more fabulous. 💅🏻💅🏻💅🏻

[The_Dinosaur_Heretic]

There’s also foramina lining the premaxilla, maxilla, and dentary bones. When accounting for tooth slippage, the tips of the upper row of teeth fall short of the foramina on the dentary when the mouth was closed. This suggests that the foramina supplied nutrients or maybe blood to some kind of extraoral tissue, and that tissue encapsulated the top row of teeth when the mouth was closed, keeping the teeth moist and preventing cracking

[sister]

The evolution of understanding....absolutely brilliant!!!

[JoeSc.]

Retractable lips when intimidating is a must! Also means it could smile 😅

[jamesmarshall]

All fun and games till a 40 foot long killer lizard looks at you and licks its lips

[lukaskywalker]

Now Michael Bays ninja turtles having lips seems more realistic

[MichelleIbarraMHAEdD]

All of a sudden, T-Rex is not so frightening as I envision Mamma T-Rexs' wearing lipstick. 😂

[_lime.]

The other part of this is understand what lips do and why some animals don't have them. Crocs don't have them as water needs to drain out of their mouth. They have a flap in their throat to prevent them from swallowing water. T-Rex has no flap (granted it's not semi-aquatic) and would have a hard time keep water in it's mouth to drink if it couldn't seal it's mouth.