World's Best Tyrannosaurus Skull shares secrets: No Lips! +7 other facts about Trex you didn't know. 

BTW, Fossil Crates sells that very T. rex skull as part of our Total T.rex rex package here www.fossilcrates.com/collections/museum-quality-skull-casts/products/totaltrex

Reptile lips are more likely if the animal uses weaker bite forces when attacking its prey. Komodo dragons have a very weak bite force, using their sharp teeth and venom to subdue their prey, thus those lips are never involved in being hit with a huge opposite force to the direction of the bite, which could cause damage. Reptiles cannot snarl their lips like mammals can, so for reptiles with huge bite force, such as crocodiles and T. rex, lips would be selected against, as they would become dangerously damaged whenever the predator attacked its next meal.

Great Video Tracy you did a great job describing Tuft’s scull. You covered all the best segments and there primary functions in a comprehensible layperson language. Not a simple thing to do. You are truly gifted in so many areas.

Prehistoric Planet designed a Rex with lips. With our without I'll always love Rexy. What's most impressive with that design were the neck muscles though. One of the few to get it right. They were huge.

Awesome, great video, this is the best explanation on why theropods didn’t have lips, Tracy always does a good job!!

Yeah, never brought that lip thing in teropods, specially those big theeth animals. People often see them as some kind of lizzards or any modern animal, even knowing they're not. Great video, thanks. I'll use it as a referrence.

That was awesome. Would love to be there. Good points on the lips!

There is still an argument to be made for lips.

Ur content is awsome, i finally found a non biased paleo channel

insteresting , great video

The closest relatives of dinosaurs are birds and crocodiles which are all grouped together in the order archosaurs. Birds are of course the closest relatives because they are theropod dinosaurs themselves. Neither birds nor crocodiles have lips, and the only living group of reptiles to have lips is the archosaur's sister group, the lepidosaurs (which includes lizards and snakes). Mammals doesn't count ofcourse because of their distant relation to reptiles in general and due to the fact that they posses muscular lips(the muscles also provide support to their facial skin) which even lepidosaurs do not have either. It would seem that lips are the most logical thing for an animal to have but that's not the case. If we take into account the morphology of the mouth and the structure, lips are not a necessary ''apparatus''. Also, the areas on the maxilla and dentary bone that appear to supply blood to lips could also provide blood supply to nourish large facial scales as well. Also the mandibular teeth (the lower jaw) are protected inside the mouth, a feature unique to theropod dinosaurs. And because the lower jaw fits inside the upper jaw, you can see how far down to the lower jaw the upper teeth reach in this figure. Not the best space for a lower lip to develop and provide cover to the upper teeth especially without the present of facial muscles to support the lower lip. As for the teeth in the upper jaw, firstly we see animals today with exposed teeth and secondly reptiles in general shed their teeth constantly in their lives. So, again, no need for an upper lip to cover and protect them. Large facial scales could also provide some good cover as well and be better suited for intraspecific competition

Yes thank god I am friends with him on Facebook

I don’t think that a tyrannosaurus would not carry its young like a cat would it would probably carry its young like a crocodile

If T. rex face bite would T. rex use the posterior and anterior side of the teeth ?

Awesome analysis. Do you have any timeline on the horizon to bring the scaled skull back to the shop?

So his points for a lack of lips is because the teeth sometimes extends pass the lower jaw? That's called tooth slippage buddy and skull distortion. Also theropods wouldn't have closed their jaw that tightly or all the way. Also their are animals with LARGER teeth to face ratio that EASILY fit in to lips. Next is him saying that the foramina is like that of crocodiles or gators. First off the skulls are nothing alike, they have way different textures and sculpting on the them. Also tyrannosaurus and theropods in general don't have that much foramina, and if I'm correct they have it in the 70s or 80s, While crocodiles and gators have a average of 100 foramina in each major bone and averages 1000 foramina. So basically tyrannosaurus doesn't have enough foramina to be lipless. Not to mention the fact that theropods and crocodiles have WAY different lifestyles.

Wow that was very good and interesting

Hoho! Tyrannosaurid teeth in the Morrison Formation? Goodness me!

Never heard of Tracy Ford before, he Is a tyrannosaurus expert ??? Im just a Rookie thanks But i like the no lips theory I cannont convice about lips thing

12:10 so 28 + MPH ?

It doesn’t make much sense thought. Crocodiles teeth are hydrated because they spend most of their time in water. Having them sticking out would mean they would be dry?

Tracy's first point about the upper tooth being too large to house any lips already leaves me unconvinced. First off, the teeth of theropods going into their lower jaws is not anything unique amongst reptiles because varanid lizards (which them and all other lepidosaurs are on the other side of the saurian phylogeny tree) also have upper teeth that goes into their lower jaws yet they still have lips covering them. Sure their lower jaws do not go into their upper jaws when they do close their mouth, but their upper teeth still goes to their lower jaws regardless. Even when theropod teeth does go past the bottoms of their jaws, it is either an outlier or they just do not go far enough to have lips being a disadvantageous trait like you two are suggesting. The only times I would say an animal's lips would be disadvantageous to the animal are those in bulldogs as you mentioned, they would end up biting the lips. Speaking of which, the bulldog argument is also one I do not find convincing because they have oversized upper lips that are too large to align with their lower lips. If T.rex did have lips, than it would have more facial tissue on its lower jaws to have larger lower lips and the gap between the lips and the jawbone itself (as you would see in Rebor's Kiss Model) would have been bigger too so it can fit them. His second argument also does not hold water because crocodilians have a lot more foramina that they use to detect their prey when entering in the water (not like sharks though which use electroreception). T.rex itself does not have as much foramina since they primarily would have used their great sense of smell along with great eye sight (which Tracy mentioned) to find and detect their prey. Also, varanids (again) also would have used their teeth to tear into prey and they too would have been sensitive due to having foramina, but still have lips covering them due to extra facial tissues. Other than that, it would have been used for various structures to connect or or pass through. I could be wrong of course, but those are my reasons why I am not convinced that theropods (especially T.rex) were lipless as Tracy would suggest. Edit: I don't know why RU-vid is making those huge gaps in my comment, so I literally have no choice but to edit the comment to remove it instead of copying and pasting it then try to remove it.

The lip debate is still going

🤩🥳 🦖 Brian, Tyrannosaurus Rex is not a Genus after all, Tyrannosaurus had 3 Species. Tyrannosaurus Imperator and Tyrannosaurus Regina.

T. Imperator is the Largest.

I know everyone laughs at the "bulldog lips", but they are actually flews. They attach pretty high up on the maxilla. If dogs can eat without biting them, why can't a tyrannosaur? They would most likely have wrinkles as well to help the blood wick off them as they ate. I've seen more than one artist representation of a carnotaur with flews, so I mustn't be the only one who thinks that.

No lips make much more sense than lips i hate paleo artist that depict dinosaurs basing themselves too much on small ass relatives of today like little birdies or emmus little lizards you see how agresive a eagle face is and is much smaller than the little birdies they depict them as