✅ PATREON ✅ www.patreon.com/EDGEscience ✅ STICKERS & SHIRTS ✅ www.redbubble.com/people/PainterRex517/shop?asc=u&ref=account-nav-dropdown ✅Facebook: facebook.com/ExpeditionDG/ ✅Twitter: twitter.com/EDGEinthewild ✅Instagram: @edgeonthetrail ✅ MUSIC ✅ “EDGE Theme” - Taung Child / Reuben Cozens “Aphex Twins” “Last Stop” - Karl Casey “SciFi” - Bensound “On The Ground” - Kevin MacLeod “Birth of a New Day” - 2814 “Night Crawler” - Karl Casey “Reptile” - Karl Casey __________________________________________________________________ If I've used something on my video that you don't want me to use, PLEASE EMAIL ME first before flagging a video, I'm very reasonable and will take the video down to replace whatever image or video belongs to you. Email: expeditiondiscoveryguild@gmail.com __________________________________________________________________ RESEARCH Bouabdellah, Florian, Lessner, Emily, and Benoit, Julien. 2022. The rostral neurovascular system of Tyrannosaurus rex. Palaeontologia Electronica, 25(1):a3. doi.org/10.26879/1178. palaeo-electronica.org/content/2022/3518-t-rex-trigeminal-canals Creech, J.E. 2004. Phylogenetic character analysis of crocodylian enamel microstructure and its relevance to biomechanical performance. Unpublished Master's Dissertation, Florida State University, Tallahassee, Florida. Morhardt, A.C. 2009. Dinosaur smiles: do the texture and morphology of the premaxilla, maxilla, and dentary bones of sauropsids provide osteological correlates for inferring extra-oral structures reliably in dinosaurs? Unpublished Master's dissertation, Western Illinois University, Macomb. Soichiro Kawabe & Soki Hattori (2021) Complex neurovascular system in the dentary of Tyrannosaurus, Historical Biology, DOI: 10.1080/08912963.2021.1965137 __________________________________________________________________ Intro - 00:00-01:50 Opening Statements - 01:50-02:58 The Evidence - 02:58-08:37 What Does It Mean? - 08:37-14:06 Sensy Snoots - 14:06-18:25 Lips Again? - 18:25-24:41 What Do We Do Now? - 24:41-25:50 Outro - 25:50-26:41
I’m a dental hygienist, and a paleontology enthusiast as a hobby. I love this video! Trigeminal nerves, labial foramens, nerve innervations, I studied all of this in humans. Amazing video! Thank you!
Since you actually know a thing or two a about dentition I’m very curious to know what your thoughts are on the hydration argument for lips. While I do think theropods likely had “lips” some of the arguments from the pro lip side of the argument are pretty poor, especially what I call the hydration argument. The whole idea is that theropods would need lips to hold in saliva and hydrate their teeth or else they would become brittle due to a lack of saliva/hydration. This argument never made sense for the reason that there are many animals, Smilodon for example, who had exposed teeth and seemed to fair just fine. Also many animals constantly regrow their teeth, like crocodilians, couldn’t theropods like Tyrannosaurus have been the same? I’m really curious to know your opinion.
@Kiera_rdh I can understand your enthusiasm, and based on that I'm recommending Prostho Plus, by Piers Anthony. It's light SF about a dentist who got abducted by aliens, and stuck with working on the dental problems of various aliens. A fun, lighthearted read, even if dentistry isn't your thing
Something that in my eyes the authors kind of overlooked is that basal pterosaurs don't really look like their derived relatives, several people have suggested that early forms had lips that covered their teeth. Also the way they handle beaks here is kind is weird in my eyes.
If I had a nickel for every time a publication inconcluded by saying "More work needs to be done...", I'd be able to fund some of that follow-up research.
I still believe that T-rex and its close relatives most likely had lips. The salivation aspect is what I'm mostly basing this on. If T-rex salivated a lot and didn't have any form of lip-like structure to contain it, then that would lead to a lot of drooling. That would in turn waste a lot of water, which as everyone should know is really important. If it had lips, it could retain the water used for saliva production. It would be interesting to see if we could calculate the rate at which T-rex salivated. That would make my hypothesis a bit more well-informed. I would also support a sort of half-lip morphology, where the upper jaw was the one that had the lip, but the lower jaw didn't. The teeth of the upper jaw would be protected from the elements by the lip, and the teeth of the lower jaw would extra protect by being deeper in the mouth. All and all, this is a really interesting topic, and I hope more work is done on it in the future.
I could see the excess saliva being used to lubricate the throat as well to make it easier to swallow large chunks of meat and bone since Rexy likely didn't chew much.
@@Supiragon1998 My main argument is based on salivation more than tooth exposure. Also, looking online at pictures of both Tasmanian devils and Opossums, most of the images show no teeth exposed. Leaving that aside, the only teeth that are exposed for those animals are their canines as you've pointed out. If t-rex had no lips, every single tooth in the upper jaw would be exposed. I don't think these are comparable.
@@Supiragon1998 that was one of the worst arguments against lips, exposed canines in mammals play social role and have little to do with them having or not having lips, which they have, but what's your argument should do to make us change our mind is hard to get, mammals are not closely related to dinosaurs.
When I did comparative anatomy I was shocked by how similar Theropods skulls were to modern Crocodilians. It's a wonderful thing that even after thousands of papers that we're still learning about T. rex.
At the moment I’m inclined to believe that lips were more likely in some theropods than others. I think that abelisaurs are the most likely to have had lips, while spinosaurus and theropods such as dilophosaurus were less likely, and tyrannosaurs and other theropods being somewhere in the middle. I usually draw theropods with kind of “half lips,” where there is some lip covering on the base of the teeth, but the tips are exposed.
@@The_Cosmic_Yog-Sothoth Alright. But then you know the pro-lip Gestapo who have overrun the Paleoart community. Quite annoying that they would try to convince people that Tyrannosaurus was an oversized, overweight, two-legged gecko with chicken feathers glued to it rather than admit that Dinosaurs are NOT lizards. Trust me, those people can be judgement at times. In fact, I even git downvoted by a mob of them whenever I disagreed with them.
@@The_Cosmic_Yog-Sothoth There is no evidence that lips would be damaged by high bite forces, considering the lips would not be in the way of the teeth, nor would the high forces they would be subject to do much to hurt them. They would have still had a degree of flexibility, and could deform out of the way when struggling with prey. Plus they were fleshy, not solid, which helps absorb impact, not that they would be subject to much impact anyway. Based on evidence in the face, specifically the location and number of foramina, T. rex and other large therapods had lips with a high degree of certainty. The foramina count most resembles animals with fleshy, immobile lips.
@@CoreyStudios2000 "pro lips Gestapo" oh my god, are some people really that hurt that terrestrial therapods like T-Rex and co. might had lips, like most modern terrestrial animals do?
For me personally, I don't understand why for some people it seems so impossible that dinos could have lips, feathers, or feather like hairs, etc. I mean there's plenty we truly don't know and many more we won't ever know, so I find it silly to discount these features as ridiculous because it makes them less scary or doesn't match what they grew up with. I find these discoveries so interesting and exciting as we get better understandings of their anatomy and get a better look of what they may have looked and acted like.
Okay - but think about "lips". All mammals have them - all mammals *need* them. Egg-laying vertebrates, on the other hand, don't. Maybe some muscles around the mouth, but not true "lips".
@@rcruz4510 I guess so, but many reptiles do have a form of lips, I wasn't meaning lips in the way that mammals do, and many mammals aren't able to do much with their lips, one reason why so many use their tongue to drink since they can't use suction like us due to their lips not being able to seal all the way like we can. I mean I'm sure dinos don't have lips in the sense like humans or primates, but I'm sure some had some sort of lip covering, rather than just straight exposed teeth like crocodilians. I do understand your point. I just call coverings around your mouth that cover hide your teeth lips.
If there's one thing I've learned about Mother Nature, it's this: She will make rules that govern all life, but she would also make an exception or exceptions to those rules.
I'm still on the pro-lip side. Not only makes it more sense to me, but contrary to what you mentioned several related groups like early pterosaurs don't have evidence for beaks. Like the early-diverging Anurognathids or, more importantly, the basal Dimorphodontids. (though those are often restored with one anyways) I like the idea of T. rex having keratinous covers on its snout to protect against damage, though; Essentially halfway to a beak already. Would be interesting to know if early toothed birds had their teeth halfway covered by their beak, so they're inside the mouth when closed. But I keratin doesn't preserve that well, unfortunately. (edit)
I think the lip debate had to bring up bird relatives more often, like dromeosaurids are almost aways reconstructed with lips, but in my opinion it would be more likelly for them to be lipless than it is for tyranosaurids
@@italucenaz just because they are closely related to birds doesn’t mean they had to have similar traits, we can’t just fill in the unkown with bird traits as these evolved separately at different times in different stages. Just because birds don’t have lips doesn’t mean every related animal lacked them too. Besides birds have evolved very far from the basal dinosaurian condition. Having a beak which most therapods lack.
@@The_Cosmic_Yog-Sothoth I am confused how bite force would sustain damage to the lips, they may not have independent control of the lips but that doesn’t mean they can’t deform when biting, also it’s soft tissue it wouldn’t be affected much by bite force.
@@The_Cosmic_Yog-Sothoth why would the lips be sustaining all the force of the bite? Even if it absorbs some of the force it would lessen the amount of damage to the teeth, just because they are replaced doesn’t mean it’s advantageous to constantly shed them. Also many modern predatory lizards have lips and they don’t get damaged from struggling prey to the point of selecting against lips.
Comodo dragons also have lips, although they have the teeth which can't be seen from outside to tear flesh off of any animal, and they salivate constantly. The saliva is what paralyzes the animals they bite, as it contains many bacteria. Perhaps T-Rex used a similar strategy? I can picture a salivating T-Rex that'd bite a large prey and pursue it until it dies.
It's not necessarily a myth, more a misinterpretation of the data. See Komodo dragon venom doesn't target nerves like say a cobra, or muscle tissue like a rattlesnake, instead it acts as an immunosuppressant. So bites would swiftly become infected and the assumption was that this was because the bite was causing the infection itself, rather than promoting new infections.
@@horse14t My bad, in 2009 they found out it has venom glands, not toxic bacteria. I should watch newer documentaries about komodos 😅 The myth is not very old, though
Komodo dragons have a relatively weak bite force compared to their size, Trex on the other hand is famous for its bone shattering bite force, it is literally the pinnacle of evolution in terms of a devastating jaws. It wouldn’t require the use of venom to take down its preys ; the use of venom could actually make a lot more sense for sauropod hunters
10:05 makes sense, since snake venom glands are modified salivary glands and since the salivary glands are innervated by branches from the facial nerve (VII), it does make sense in snakes the trigeminal nerve being the one NOT controlling those venom glands.
This is why it’s so upsetting that STAN was sold. I hear so much of “they got everything they could from it so it’s fine” nope. Like this with sue is just one example of how ideas and technology progress
Wait wait wait wait wait. Did that one scientific diagram refer to a type of snake with noodly upper lip appendages? Because I think that's what's important here.
I don’t trust anything with big teeth AND lips. Like horses, I don’t trust them. And people just ride them with the assumption it won’t decide to kill you, it easily could!!!!
@@horse14t as I suspected, I watched a horse at a trot for no real reason just kick a good sized tree spraying bark and then just zipping off. Like he was letting me know.
Wait, crocodiles and Theropods regrow their teeth throughout their lives. Even if the teeth become brittle, the teeth will regrow and be replaced, right? So with this in mind, could it be possible for an exposed tooth feature? Could you share the sauropod lip fragment? I think I heard about it a year or so ago.
Yeah the whole teeth becoming brittle argument never made sense for that reason alone. Also there are many animals, Smilodon for example, who had exposed teeth and seemed to fair just fine.
All hail the almighty algorithm! This popped up randomly in my feed and I am not impressed! I am more than just impressed, in fact I am very grateful for the producers of this fine presentation. Thank you 🙏
I enjoy all the footage of the fossil reconstruction at the Denver Museum of Nature and Science. It's a great centerpiece as you walk in the door. Although, it was made in the 90s and very much reflects the outdated understanding of these creatures, particularly with how vertically oriented it is and that super wiggly tail. I would love it if they added an exhibit at the base describing how the theories behind tyrannosaur anatomy and morphology have changed since then.
As someone who suffered with Atypical Trigeminal Neuralgia on both sides for 12 years, very neat video! Imagine a Trex getting something like TN!? Yikes.
I nearly choked on my coffee from 18:33 💀 Honestly these studies just make me so pissed because I just end up wanting to hug a dinosaur and tell it how awesome it is, but then I realize I'll never be able to do that 😭
Another point that may not hold much weight scientifically, but if you look at the jaws of many theropods, in a closed position the top jaw tends to extend beyond the bottom jaw so that the bottom jaw can tuck into the top jaw. If soft tissue was minimal in life, this means most theropods would have comical overbites. Just looking at their skulls, it's hard for me to resist the idea that there was substantial soft tissue flushing the tips of their top and bottom jaws together.
Yeah, in Tyranosaurus for exemple there is a wide variety of overbites, in smaller ones I can see a lizard like lower lip that covers the teeth from the upper jaw, but I can't imagine that in other specimens with larger overbites, it's seems like too much soft tissue hanging there just to conceal the teeth, I deffended lipped dinos for a long time, but now I think it's time to abandon this fight
As the camera pans over the skeleton at the beginning of the vid I noticed that the bony palate was very high. Could there have been an olfactory organ requiring some room to manoeuvre for the tongue?
Comment before the videos finish: the t rex has traits of crocodile, snakes and others which can detect small vibrations in the water, maybe in the air for tiny movements in air and water.
This is probably unlikely, the greater density of water makes these pressure sensors much more useful (it's why virtually every fish has a lateral line). But air being much less dense means any "signals" transfer much reduced distances, so T. rex would virtually have to be right next to something to even feel a slight difference. However air is still able to transmit odors effectively, and we do know Tyrannosaurus was particularly sensitive to this.
Apparently they had a snout as sensibe as a regular theropod, not like a Spinosaurus that used to feel vibrations in water, the big bundle of nerves on Tyrannosaurus were probable used for something else, likelly a keratinous covering or something related to maturity
Concerning the predatory theropods. T-Rex, in particular is described as possibly possessing vision, equal in scope to a modern day eagle... But what if, like many animals with acute long range vision, their short range was limited or relatively distorted? The nerves along their lips could pass information to them that they were in striking distance, even better than binocular vision. We speculate that spinosaurs and crocodiles use these nerves in hunting, why not other theropods. they might also be able to sense areas of maximum bloodflow, and therefore maximum damage, from a strike.
You specifically differentiate between teeth and "tusks". Is there actually a difference chemically or structurally? I agree that lips were likely, but there are a lot of avenues that need to be investigated. A couple of points that I'm disappointed aren't discussed more: 1) what does it matter if the teeth slowly get brittle if they are just gonna get replaced? If the tooth takes longer to become brittle than it'd take to fall out, there's no issue. (Assuming the decay factor isn't dissimilar from the damage our teeth take from mouth-breathing.) This could explain the hibernating croc issue. Either way, if exposed teeth were automatically a deal breaker, how would there ever be transitional forms between teeth and tusks? 2) there have been mostly terrestrial neosuchian crocs many times in the past. Many of these, for example Kaprosuchus, likely had croc-like exposed teeth. What's the deal there? 3) what about lips BEHIND teeth? Even if you exclude tusks, I know at least naked mole rats have this. Is there a distinct skull structure in this case? Point being, exposed teeth does not mean a permanently open mouth. 4) you mention that rexes "rough-housed", could that be relevant to the convo? Like, would the lipped or lipless states have an advantage in combat? Maybe teeth would be easilly destroyed on a face-bite if exposed (supporting the lipped model). Heck, for all I know, maybe the big upper teeth protected the mandible from starvation-inducing damage.
The difference is structural. Regular teeth have a soft core of tissueand nerves, a layer of dentine, and a coating of enamel. Tusks are almost entirely solid dentine.
So many things I want to know about her, how did she die? Is she a "she" at all? And how would we know the difference between a male and a female T-Rex? I love these animals, so much curiosity.
While I do think theropods may have had “lips” some of the arguments from the pro-lip side of the argument are pretty poor, especially what I call the hydration argument. The whole idea is that theropods would need lips to hold in saliva and hydrate their teeth or else they would become brittle due to a lack of saliva/hydration. This argument never made sense for the reason that there are many animals, Smilodon for example, who had exposed teeth and seemed to fair just fine. Also, many animals constantly regrow their teeth, like crocodilians, couldn’t theropods like Tyrannosaurus have been the same?
I think you mean "Teeth Hydration Argument" as what i think is the actual hydration argument is that the lips are needed to reduce the amount of wasted saliva basically be more hydrated in general
@@rodrigopinto6676 I think there were abelisaurids with more powerful bite force, but whatever, also, I think smaller pack hunters would've been way better hunters than the T-Rex.
@@alvaronavarro4895 Pretty much all the papers point to rex having the strongest bite force of any terrestrial carnivore. None of the abeliosaueids come even close.
Seriously, what's the music from 0:58 - 1:49? Because when I had Jurassic Park 3 and The Mummy 2 on DVD, this commercial full of clips from action movies always started after you clicked 'play' on the DVD menu and this song played in the background! Its driving me insane, I KNOW this song because I heard it so often growing up because it got me pumped, whats it called???
i was just going through this myself! and i think that's all the song is from, I found a snippet on RU-vid from the Jurassic Park DVD from 2000, i think universal was just testing it as a theme? ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-s2oqSE4roj0.html (the link to video)
It makes more sense to me that they would have had lips, I think in part the 'cool' factor of having exposed teeth plays a part as well, it makes them looks more dangerous. The discussion often seems to be pointed to prove that lips were present, but why is not not the other way around, to prove they didn't have lips?
@Nova Animations I mean in some regards you can prove a negative.. I can prove my cat doesn’t have six legs… but there definitely are situations where we don’t know enough to do so. It stands in reason in any paleontological question we would be hard pressed to prove a negative
It's really amazing what we can find out from the science we have today, it's also fun to imagine what scientist from 100 years ago would think of this
i believe in t. rex having lips but i think you should've mentioned tasmanian devils, they have teeth that stick out of their mouth and i don't think they'd exactly be considered tusks since they're so small?
There’s a different between having 2 teeth sticking outside of the mouth and having no lips, although the tip of the teeth is sticking outside of the mouth, the majority of the tooth is still protected being the lips
You know, I was thinking and... what if the mouth was a fusion on lips and non lips? I mean, is not the first time that the reality is totally different from what we think, look at the Hadrosaur's foots? Idk, maybe a structure like a bird mouth with a lizard one
On air? Unlikely, the only animal I know that does that on air is the echidna, but it eats ants and termites, it put its snout right inside where the bugs are, a large terrestril hypercarnivore would never do the dame to sense their preys, they used their sense of sight, smell and hearing for that, that were incredible btw
@I ate the spacebar in a healthy infividual, lips wouldn't get in the way of teeth, anyway, I agree they didn't have the teeth pouch like lizards do nowadays, but not because of this argument
Isn't it pronounced "tri-JEM-inal?" I'm far from a medical expert, but my initial response is that it's juh like gem and not guh like game. Great video! Just saw another one on your channel and now I'm watching this. Love paleontology.
They would salivate when being active probably, there is no evidence of how much they salivated along that day, just that they had big nerves on the area where there should be salivary glands
