Why Dinosaurs Were So Successful + Busting Dinosaur Myths | GEO GIRL

[@GEOGIRL]

Hey everyone, I just wanted to come back to this video and let you all know that I filmed this before I watched Jurassic World Dominion, and now that I have, I would like to officially state that they did a REALLY good job with dinosaur scientific accuracy in that movie! I mean did you see how many dinosaurs had feathers! And many even had feathers with the exact color reconstructions that scientists have made ;D It was amazing! The only scene I would raise a red flag at is the one with the raptors who are trained to go after the red dots. They seemed to be keeping up with both the car and motorcycle which looked like they were going a lot faster than 40mph haha (but I still loved that scene) ;)

[@Smilo-the-Sabertooth]

The Atrociraptor scene was definitely one of my favorite scenes. Despite whatever inaccuracies there are, I thought it was a really thrilling chase scene, had my all hyped up and on the edge of my seat the entire time.

[@GEOGIRL]

@@Smilo-the-Sabertooth I know right!!! :D

[@oker59]

I haven't kept up with the Jurrasic park movies. The last Jurassic Park movie I watched, there was a cloaked dinosaur. I actually kind of see where they could have gotten the idea! There's a squid that can cloak! I've seen the video!

[@nicholasmaude6906]

According to Klayton Fioriti ( kzbin.info ), Rachel, the extended director's cut is better than the theatrical release as it fleshes out the story more according to him.

[@dukecity7688]

ok. Now that you've given it the thumbs up, i'm going to watch the movie.

[@sonjavandenende9586]

Rather than evolving hollow neck bones "just so they could lift their enormous necks" (16:02), sauropods were able to evolve long necks because they already had hollow bones. Pneumatized or hollow bones were a feature of saurichian dinosaurs (to which sauropods belong) before sauropods reached the shapes and sizes they did. That said, thanks for another very interesting vid. :) I'm loving your channel's content.

[@GEOGIRL]

Oh wow, thanks for this information and clarification! How amazing :D

[@goldwolf0606]

@@GEOGIRL someone didn’t do their homework 😂

[@GEOGIRL]

@@goldwolf0606 Lol what do you mean! I did too, I just didn't go that deep! hahaha 🤣

[@takashitamagawa5881]

@@goldwolf0606 Come on, these videos require a lot of work and there's always more that could be said.

[@Crunkboy415]

The dinos got so big because they were juicin' with the 'roids!🤣

[@ricktownend9144]

Great video! re feathers, you mention keeping body-temperature, and brooding eggs/chicks, but, just by watching my chickens' behaviour, I've noticed several other uses for feathers, which might equally apply to (other) dinosaurs: gender-recognition - male chickens have distinct feather styles; individual recognition - pecking-orders depend on knowing who you can peck; running faster - to get to food or away from danger, or just as an expression of feeling good; lining nests (plus removing or losing breast feathers warms the eggs/chicks better); display by males (and sometimes females, towards a new introduction to the group); notice (by males) of a sexual advance (neck-feathers raised); something (on the hen) for the male to hold on to during mating; feathers can be a strategic loss during a predator attack - they will re-grow next moult; waterproofing - even chicken feathers are slightly oily, and will protect against light rain; mood expression - e.g flapping wings, or shaking all the feathers can be wonderfully expressive; group 'therapy' - the chickens usually all sit down together to sort out and re-oil their feathers. I haven't noticed chickens actually helping others to preen the 'difficult' feathers (e.g. on the back of the head) but I gather that the corvids do that - would be good for couple and social bonding.

[@GEOGIRL]

Oh wow! I had no idea, how cool! I never thought about it in a social bonding kind of way, but now that you mention that it totally makes sense! Now I am wondering if dinosaurs bonded in a similar way, maybe not the solo species but I bet the community building species probably did! ;D

[@claudiaarjangi4914]

It is so cool living with different animals ( birds, cats etc).. & Cooler having the curiosity to watch their real natural lives, and seeing things most people just don't notice 👍

[@kR-qj7rw]

feathers are far more flexible on use than hair its pretty cool

[@hoi-polloi1863]

Big shout-out to Robert T. Bakker who published "the Dinosaur Heresies" in the 80s... he introduced many of the argument for dinosaur endothermy that we see in this video!

[@JMDinOKC]

But he's SO WEIRD.

[@mspicer3262]

Another way to know that dinosaurs were quite advanced, is that they didn't use any social-media.

[@KerriEverlasting]

😂

[@mhdfrb9971]

Wow so funny

[@tedetienne7639]

Thank you for a great video! It still blows my mind that the Cretaceous PERIOD alone was 13 million years longer than the entire Cenozoic ERA. Those dinosaurs had a successful thing going for a really long time! And thank you for that very first Geo Girl email update! The layout looks good, and I look forward to more!

[@GEOGIRL]

Thanks Ted! I look forward to sending more out ans getting better at it and maybe a bit more consistent haha ;)

[@KerriEverlasting]

Actually that's a really interesting titbit! It hadn't really occurred to me but now that you mention it, it IS pretty mind blowing!

[@tedetienne7639]

Also, thank you, Geo Girl, for correctly using the term “venomous” instead of “poisonous”! You’re very accurate with your terms. I like that!

[@GEOGIRL]

@@tedetienne7639 Oh trust me I am that person that loves to correct people when they call snakes poisonous!! hahaha It's probably annoying, but I gotta do it LOL

[@takashitamagawa5881]

Another highly informative video. It’s been noted elsewhere that the speedy mean dinosaurs featured in the Jurassic Park movies are not Velociraptors but rather were Deinonychus, described by John Ostrum of Yale University. They were the right size, shape, and function but don’t have such a catchy name. Mammals don’t nearly reach the sizes of the giant Sauropods like Apatosaurus (Brontosaurus) or Brachiosaurus. One reason is that their bones would be too heavy. The bones of those giants have lightening mechanisms such as air sacs, similar to birds. And that brings up another advantage of dinosaurs in that they had a more efficient breathing mechanism than mammals. The breathing cycle is circular which avoids the exhaust volume of exhalation which reduces the amount of fresh air that can be drawn in during inhalation. That's another trait they share with birds.

[@Crunkboy415]

The one exception would be the mammal that went back into the sea and became the whales. Because water of course allowed them to support more massive bones thus they grew to gigantic size comparable and at times larger than dinosaurs.😁

[@goldwolf0606]

Oxygen concentration in the Air has gone down a lot too. That’s why bugs aren’t as big as before. The environment changes and limits too.

[@takashitamagawa5881]

@@goldwolf0606 Yes, I've seen estimates that the oxygen content in the atmosphere may have averaged as high as 30% in the Mesozoic. Of course it was a long period of time and the percentage must have varied.

[@rabidmidgeecosse1336]

given its a Hollywood film we should be thankful they have even passing resemblance to ancient animals. Hollywood and accuracy rarely pass close to each other.

[@hydrolito]

They said they were hybrid animals in Jurassic Park movie so not pure dinosaurs in story although what else they combined with velociraptors in story do not know.

[@una7500]

I love your videos because they are very detailed. You actually have something to say. I rewatched this one because you say soemthing that I think is wrong. You say that sauropod neck length enables them to reach physically higher food sources. This is not the current thinking except possibly in the Bracheosauridae. The rest of them held their necks at shoulder heighth and swung their necks from side to side like a giant lawn mower reaching the maximum of food sources without having to move. At least, that is the current thinking. There was an excellent paper some years ago in PLOSone discussing an evolutionary cascade model for sauropod neck length and also discusses feeding behavior and their unbelieveble growth rates,

[@markomalizani7751]

For someone like me who knows almost nothing about the subject matter, but is fascinated with the same, this was well presented and easy to understand. Thank you.

[@nicholasmaude6906]

My favourite Triassic Dinosaur is the Coelophysis (Shown on the first episode of the BBC's excellent "Walking with Dinosaurs" TV series). The raptors in the Jurassic Park movies were Utahraptors.

[@Dragrath1]

Probably should have been more mention of the croc-line archosaurs given that they were ecologically dominant during the Triassic therapsids were largely extinct by the end of the Permian with dicynodonts and eutheriodonts being the only groups to survive the great dying. While they did re-diversify they were not overly dominant in the Triassic having been in lockstep competition with archosauromorphs which appears to have driven a metabolic arms race towards higher metabolisms between the two groups. At the megafaunal level to my knowledge those niches were primarily occupied by archosauromorphs most notably the pseudosuchians which grew up to comparable sizes to ornithischian dinosaurs. (The active metabolisms likely ran gambit on a spectrum of endothermy and ectothermy in fact if modern birds are any indicator they may very well have been able to switch between the two states since a number of birds from hummingbirds to chickadees exhibit the ability to enter a selective ectothermy or torpor state. With tidal lungs synapsids probably faced a disadvantage in terms of oxygen intake as the increased muscular exertion and the formation and presence of stagnant air zones in tidal lungs means they lack efficiency at breathing which is exacerbated at larger body sizes. With those drawback they were likely restricted in their ability to compete energetically at large body sizes compared to the unidirectional airflow of diapsids (which in archosauromorphs became coupled with endothermy) which don't suffer from these same flaws. The archosaurs furthermore developed air storage sacs which in both the pterosaurs and saurischian dinosaurs were incorporated into their bones to grant them hollow bones which would enable both flight and a means to bypass the solid bone weight limit which constrained all other terrestrial tetrapod megafauna pseudosuchians, ornithischian dinosaurs, Cenozoic mammals and the Cenozoic sebecids of South America. Also we now know that the "fuzz" of pterosaurs was actually homologous in both morphological structure and growth suggesting that the origin of hair-like feathers predates dinosauria as a whole a finding supported by evidence showing these primitive hair-like feathers were present in ornithischian dinosaurs even if they lacked the hollow bones of their cousins. In terms of other traits and comparisons we don't really appreciate it but the synapsids which survived the great dying all had/have a unique characteristic which we as their descendants share that other tetrapods don't have, the ability to chew. This adaptation took many millions of years to evolve over the course of the Permian with significant alterations to jaw and teeth structure unique to our clade. This likely was a core component for why they were able to persist through the Mesozoic despite the gross inferiority of the tidal lung system. Gastroliths and the gizzard were the dinosaurian counterpart to chewing but that relied on the ability to find suitable rocks and or grit(depending on the animal's size/diet) to wear down their food. As for another note related to the Triassic recent work has shown that the Carnian Pluvial Episode/Event (CPE) was an underappreciated mass extinction which was instrumental in shaping Mesozoic and subsequent ecologies. This event was associated with the Wrangellia Large Igneous Province surviving remnants of which today are incorporated into the Wrangellia super terrane which evidence suggests was part of a large mature volcanic arc complex out in the open Pacific(then probably part of the vast global ocean seeing as Pangaea still existed and the North American coast would have been thousands of kilometers away likely fairly analogous to Indonesia before it collided with/was accreted by North America between the late Jurassic to Cretaceous/Paleogene around (170 to 50 Ma). California Oregon Washington Alaska much of British Columbia parts of Idaho Nevada and other bits west of the Sevier orogeny and early Laramide orogeny which formed North Americas own continental subduction arc. Its a great geological train wreck in western NA which may explain how the clearly Asiatic branch tyrannosaur T-rex got to the continent along with the return of sauropods and sauropod ecosystem engineering to North America via Alamosaurus during the Maastrichtian. In fact there seems to have been a continental interchange ongoing between Asia and North America when the Cretaceous violently came to an end as the arcs which would later become folded into modern Alaska would have connected Siberia to North America based on some of the more recent reconstructions.

[@ogrejd]

@5:15 - Michael Crichton's sources (from when he was researching for the book) had basically mislabeled Deinoychus as Velociraptor. They kept that oopsie for the movie (and the sequel novel and later movies) because, of course, "Velociraptor" is a far cooler name.

[@GEOGIRL]

Oooohh! Haha that is an awesome story! Thanks for sharing that ;D

[@khango6138]

I personally use the Sauropsida definition of reptiles. Under this definition, Reptiles aka Sauropsida is a monophyletic group that includes the two major extant branches, Archosauria containing non-avian dinosaurs, pterosaurs and crocodylomorphs, while the other major branch Lepidosauria being home to snakes, lizards, etc. The real big mystery is whatever the hell turtles are, I think right now they are placed closer to Archosaurs but probably not in it. Therefore if you can say an alligator is a reptile and a snake is also a reptile, dinosaurs including birds must also be reptiles for they are far closer to an alligator than the gator is to a lizard or snake.

[@GEOGIRL]

Right, sorry I think I said this in a confusing way in the video haha, but I agree that dinosaurs and birds are technically reptiles. I just meant to say that if we think about the modern animal groups we use (reptiles, birds, mammals, amphibians, fish), then dinosaurs were more like modern birds (even the non-bird ancestors) than like modern reptiles. But I agree that phylogenetically, both groups are reptiles. ;) It is odd though that Sauropsids don't include turtles! hahaha, maybe turtles belong to their own group because they are just so unique and amazing!

[@albertnonymous1886]

Alligators are reptiles in the same way that tomatoes are vegetables, not at all scientifically but completely in the ways important in everyday life.

[@matthewbrown8679]

Sometimes a paraphyletic definition of a clade is more useful than a monophyletic definition. I don't find it at all useful to consider people to be either fish or amphibians. But in the case of birds, I can't imagine where precisely one draws a line between birds on one hand, and reptiles on the other. Enantiornithes? They are as much birds as any modern bird. Troodontids? Those that did fly may have evolved it completely independently of modern birds, but some did fly. In what sense were those pennaceous feathered flying endotherms any more reptilian than the pennaceous feathered flying endotherms we call birds? Long tails, perhaps? Then we get to dromeosaurs, which includes deinosychus, velociraotor, and yet another group of pennaceous feathered flying endotherms called microraptora. Yup, they probably flew. They couldn't climb well, and would have glided as well as a sparrow (or a rock). So their flight feathers were probably for flying, not gliding. Again, how were they more reptilian than birds? No place to draw a line.

[@punditgi]

Geo Girl is total fun to watch! 😊

[@greenflagracing7067]

Robert Bakker was an advisor on Jurassic Park.

[@matthewbrown8679]

5:02 Spielberg knew full well that what he was portraying was closer to Deinonychus in size, and that velociraptors were much smaller. He even called his dinosaur advisor to apologize in advance for the name swap. But he just couldn't not use what sounded like a much cooler name. 6:15 they didn't consult scientists on T-rex. The animators tried to make t-rex run faster, but to do so its legs had to move so fast that it looked absurd. So they slowed it down. I'm guessing that's why they had the fleeing jeep going backwards in the scene so there would be a good reason to not be able to out-run the t-rex. I think the animators may have figured out t-rex's speed limit BEFORE THE PALEONTOLOGISTS! 9:50 I'd never seen the "stride length" argument before.

[@toastyburger]

Cool shirt! You are a great teacher. Very comprehensive yet entertaining.

[@GEOGIRL]

Thank you so much! ;D

[@curtisblake261]

I once watched a rather small snake swallow a rather large mouse while camping in northern Michigan. It was creepy. And long before I ever read Saint-Exupery's Le Petit Prince.

[@patrickm3981]

Concerning the question if dinosaurs were warm blooded or not there is also an other strong hint that the dinosaurs (or at least some of them) were warm blooded. Birds are warm blooded. As birds are dinosaurs it is together with the other evidence mentioned in the video not far fetched to assume that at least their ancestors were already warm blooded. In addition it might be easily overlooked but although dinosaurs have lost their number one position to the mammals when it comes to size, birds are very successful. They can be found all over the planet and there are more species of birds then species of mammals. Therefore although they were hit very hard by the mass extinction they could almost bounce back to the top position. Probably the big luck of the mammals was that only one flying lineage of dinosaurs survived. This made it a lot easier for the mammals to fill in the ecological niches, because they were already adapted to live on the ground.

[@shanieboi86]

You made it Geo Girl, into my suggestions. I have very little interest in dinosaurs but enjoy your fact telling.

[@GEOGIRL]

Haha, well don't worry, I talk about much more than just dinosaurs ;)

[@shanieboi86]

@@GEOGIRL Already started watching them. Thanks for the great videos. 😁

[@eggprantful]

"Oh how the tables have turned." Me, talking to a rotisserie chicken, every time.

[@barbaradurfee645]

I think those thoughts when I’m cooking too 😊

[@oiocha5706]

If their diversity and numbers made them more likely to survive the previous extinction events, it should have also made them more likely to survive the KT extinction, but it didn't. Not even a single non-avian species survived, despite their incredible diversity. It just doesn't make sense. I think there's a real mystery here.

[@GEOGIRL]

Keep in mind the KT extinction was at the end of the Cretaceous millions of years later. There’s a lot of time between 200 and 65 million years ago, and although they were successful through much of the Cretaceous by the end of that period their diversity and ‘extinction survivability’ had gone way down due to both climatic changes that had adverse effects on them (before the asteroid hit) and because of competition from other species by then. Also, the KT event was very different from the Triassic one. They could escape to high latitudes during the Triassic event but they couldn’t escape the ‘boiling’ and the impact winter following the asteroid impact during the KT event. Honestly the KT event was just no fun for terrestrial life. Marine life and smaller land animals especially those that could burrow or fly had the advantage during that event. ;)

[@helmutzollner5496]

Excellent video! Thank you!

[@markmuller7962]

Hey Geo Girl I've just subscribed I love your channel 😃 On the Jurassic park velociraptor having no feathers, I think the idea of feathered dinosaurs wasn't really widespread back in the 90s both in science but especially in the popular imagination, along with what you say of dinosaurs (definitely) looking goofier with feathers. Please correct me if I'm wrong, I've grew up in the 90s but my memory is not the best 🙂

[@GEOGIRL]

You are absolutely correct! I was more so wondering about the ones that are still coming out today and why they hadn't adopted the feathered look, but now that I've seen the most recent one, I see they have implemented more feathered dinos and I love that! :D Also, thanks for the subscribing! I am so glad you love the channel ;D

[@GS-1233]

Thank you! This is the best dinosaurs video I have seen in a long time on KZbin!

[@Alberad08]

Thanks a lot for sharing this new video! Never mind, your (off course Linnean) distinction between reptiles and birds/dinosaurs made me think, "what about crocodiles than?" Dinosaurs/Birds and crocodiles are, after all we know, much closer related than crocodiles and lizards. So, as a paleontologist once put it (I guess it was Thomas Holtz), " Saying that you are closer related to your cousin because he does look more like you than to your brother makes no sense." BTW not long ago, I saw a blackbird hunting on the rim of a garden path and noticed how similar its movements were to a garden lizard: making all that weird stop and go movements, which I can only describe as "just reptile-like". A shrew would move quite differently.

[@GEOGIRL]

Absolutely! Everything is relative! I am glad you see that ;D

[@Spikklubba]

Yeah only way reptiles make sense as a natural grouping is by including birds in it, not a coincidence that zoology textbooks who separate chapters between birds and classic reptiles often use the title "non-avian reptiles". And seems that endothermy has been present in some degree among other non-dino branches of archosaurs, even in the earlier groups of crocodile-line archosaurs. modern crocodiles have gradually slided to more ectothermy as they specialised for a semi-aquatic ambush niche. Kinda weird in a way, modern crocodilians are decently anatomically built for higher activity (four-chambered heart, unidirectional airflow similar to birds) but went the way of lizards. Speaking of croc things, another thing might worth mentioning in regards to what kept dinosaurs down in the triassic are the crocodile-line Pseudosuchians, some of its members were among the top predators of the Triassic (Postosuchus for a more famous example) and did not fare well in the end triassic extinction. In the past some pseudosuchians fossils were often confused with early dinosaur/dinosauromorphs as they also were archosaurs and terrestrial with a more upright posture and some species partially bipedal with shorter front limbs.

[@JohnViolette0]

My understanding is that Jurassic Park has oversized Velociraptors because 1) Crichton wanted predators like them who would be an obvious threat to humans, and 2) Most of the world didn't know about Utahraptors until after the book was written in 1990. My guess is that if Jurassic Park had been written 10 years later it would have had Utahraptors in them instead of Velociraptors.

[@linjie1213]

That's some quality stuff. Subscribed.

[@GEOGIRL]

Yay! Thank you so much, hope you enjoy the rest of my videos just as much! ;D

[@Smilo-the-Sabertooth]

A video that discusses the success of some of the largest and some of the fiercest creatures to have ever walked the Earth, always keeps me coming back for more. 🦖🦕 But inaccuracies won’t keep me from enjoying a timeless franchise. Like Dr. Henry Wu (BD Wong) said, “Nothing in Jurassic World is natural.” It was then that I understood what he meant.

[@GEOGIRL]

Haha Yes! I will never stop loving Jurassic park and world movies!!

[@Smilo-the-Sabertooth]

@@GEOGIRL Same here!!! So glad to hear you watched Dominion. What did you think about it and what were some of your favorite moments in the movie?

[@GEOGIRL]

@@Smilo-the-Sabertooth Oh definitely near the end when Maisie got the baby raptor (I can't remember the name) to stop and look at her so they could catch her. Also when Kayla showed up to help Clair. And pretty much every scence with Ian!! I love all his little smart aleck comments when they are all together right after Clair and Owen reunited with Maisie, I just love the humor! Oh I also love it when he thinks he freed them from the mines, but it was really Ramsay! And yes, I had to look up the characters names to make this comment haha but it was worth it, loved that movie!

[@Smilo-the-Sabertooth]

@@GEOGIRL All really excellent choices of very memorable movie moments. I really loved all the call backs and references to the original Jurassic Park. Other than the Atrociraptor chase, some of my other favorite moments were the scenes with Blue and Beta, such an adorable mother daughter relationship. I also loved Dr. Wu’s redemption scene. And Dr Malcolm’s character just continues to restore my faith in humanity. He always sees the writing on the wall and is always aware of what consequences may occur when people don’t always think things through. It’s was so good to see the original cast back together again. I also loved the Rexy vs Giganotosaurus final battle scene. Rexy is always teaming up with other dinos to defeat the enemies, first she teamed up with Blue to fight the Indominus Rex, and then she teamed up with the Therizinosaurus to defeat the Giganotosaurus. Always sharing her victories with other dinos. But perhaps my most favorite moment in the movie was at the very end where the dinosaurs are coexisting with the modern creatures in there natural habitats. Such a beautiful scene, don’t you think? It’s pure poetry to me. I loved everything about this movie, I was not disappointed at all.

[@GEOGIRL]

@@Smilo-the-Sabertooth Oh yes the coexisting with modern animals that was a great one! Also when Blue came back at the end to say one last goodbye and thank you to Owen, that was my fav!

[@Dylan-vd6rz]

I can answer ur question about Jurassic Park raptors. Back in the 80s when Crichton was writing his book, Deinonychus had just recently been discovered and not officially named. Initial thoughts were it was an American species of Velociraptor. So when Crichton wanted a man sized dinosaur as the antagonist of his book he used the suspected American Velociraptor. By the time the movie started production the animal had been officially named as Deinonychus but the book the movie was based off had already named it Velociraptor years before.

[@radarcontact1974]

164 videos so far, each and everyone the product of diligent research and up-to-date data. 164 is a relatively low number for youtube standards, and that is a very good sign! It implies that Geo Girl is: 1- Not interested in short, easy videos over shallow topics. 2- Way too busy studying and working to produce en-masse. 3- Favours Quality over Quantity by default. The austere format of the material (i.e. recording in her bedroom, occasionally with a cat in the background, and the use of simple, straight to the point images without flashy special effects) reinforces the impression of her wanting to be appreciated by the substance rather than by fancy, eye-candy tricks. In a medium where 80% of the material produced by young girls can be reduced to "showing what wouldn't be out of place in any burdel", Geo Girl choses instead to go the hard way: no "Only Fans" BS but constructive, enriching information. She is, therefore, an example of real virtue, a testament to the historic determination of women scientists and a role model to follow and emulate by others of the same generation. Keep it up Girl! What you do is even more meaningful than what you think! Chapeau! 🎩

[@GEOGIRL]

Oh my gosh! I think I am going to print out this comment and frame it! Wow, thank you so much for the kind words, I am so touched that you see so much value in what I do on KZbin. I sometimes wonder if my youtube work is making the type of impact I would like it to and this kind of comment really reminds me it is good and motivates me to keep going. :) I do find it funny that you mention I am not interested in short content because I just filmed 5 youtube shorts to put out over the next month! hahaha But trust me, they are not shallow and I am only doing it because people told me I needed to get on the shorts train lol. I will still be posting my regular weekly, long form lecture though so it won't be a huge change and hopefully it'll bring some new younger viewers and students in. :) Anyway, thank you again for such a thoughtful comment! It really did make my day!

[@radarcontact1974]

@@GEOGIRL Nice to read that! You're welcome! About the shorts: be my guest! You spotted the little difference: "short videos but not shallow". That's some attention to details right there. Paleontology has been one of my favourite topics since childhood, I am curious by nature and maybe you can help me to answer a couple questions that have been itching for years. I have no formal studies in the field or means to solve the "mysteries" by myself. Basically, I'm pitching you two ideas. The fist idea is related to theropod dinosaurs: In the case of the abelisaurids, the arms became vestigial over time, to the point of uselessnes, unless for, potentially, sexual display with the help of some kind of colorful appendages. Not so in the case of Tyranosaurids and Allosaurids. It looks like the arms shrank with time to allow for a bigger head and greater bite, but remained proportional to the average size of each species. So, they were functional, not vestigial. Those "tiny" arms of T-Rex, for instance, are pretty muscular and the claws didn't dissapear. Now, some paleontologists sustain they were useless, others hypothesized they were still used to hold on to a struggling prey and others sustain they were used to "tickle the female during mating" (Gimme a break! Everything nowadays is gotta be sex-related!) And what did the females used theirs for? Long story short, daydreaming, I imagined those arms are just the right size to "bring the lunch back home". A leopard catches a gazelle, has to carry it with its mouth and bring it up a tree before eating it, just to avoid being robbed. If it was to be challenged on the way, say by a hiena, it has to drop the catch in order to defend it. But, conceivably, a T-Rex coud kill an Edmontosaurus, eat from the legs and upper body, and bring that chunky, muscular tail to the chicks and partner waiting, carrying it with its arms. The tail of the catch, aligned with the T-Rex's body, doesn't really interfere with the stride and Big-T wouldn't have to drop it in order to defend it, since it's mouth would be free to bite. And, since Edmond's tail would be partially dragged, it would be lighter to carry for those already strong arms. It would be also closer to the center of gravity of the T-Rex and wouldn't hit everything and make a lot of noise like a dog trying to pass a wooden stump through a fence. Remember that semi-mummified Edmontosaurus Tail found with T-Rex and Raptor bite-marks? And I think it was Sue, the one that got an arm almost bitten off, as if something was going for the prize and the arm was in the way? Maybe is just dumb speculation on my part, maybe someone already thought about it and discarded the possibility. But if not, there could be something interesting there as well! :D So far, I haven't read or heard about this possibility anywhere. That's why I ask. Would you check it out for me? If by chance, the idea ends up being a discovery, you take the credit. I'm no scientist anyway. How'bout a paper for peer-review? :)

[@paulohagan3309]

Totally agree. It's refreshing to see an intelligent lady like yourself put out high-quality material like this without any gimmicks or giggling every second sentence when giving out the info. Are you planning an academic career? If so, you've taken the first excellent steps.

[@GEOGIRL]

@@paulohagan3309 Thank you so much! Yes, I am currently a PhD student and hoping to be a geoscience professor after I graduate and finish a postdoc :)

[@paulohagan3309]

@@GEOGIRL Glad to hear it. I think you'll be a great asset to any institute you work in. Your YT experience will surely stand you in good stead.

[@Ave_Echidna]

I remember something coming out a while back postulating that dinosaurs were mesothermic... (cursory google search shows nothing past the 2014 study one way or the other about this...)

[@robertbradley8309]

Fantastic video! Very informative!!

[@GEOGIRL]

Thank you! ;D

[@MarvashMagalli]

Some info I knew about, other surprised me. Glad this was recommended to me.

[@GEOGIRL]

Glad you enjoyed it and learned something new ;) Thanks for the comment!

[@DrummerDaddio]

Michael Crichton based the "velociraptors" on deinonychus, even consulting John Ostrom himself to make them as accurate as he could given the knowledge at the time, and then chose to call them velociraptors because the name sounded "more dramatic". So, yeah, it's because he thought the name was cooler 🤔. I, personally, think deinonychus sounds pretty cool, so I don't agree with his assessment, but what are you gonna do?

[@GEOGIRL]

OMG! Thank you for this comment! I was wondering if this information was out there somewhere, wow I can't believe I guess the correct reason about the cooler name haha. Well, I can't blame them, but I am glad they based it off of something real! :D

[@gene108]

In 1993, “Jurassic Park” consulted with paleontologists and used the latest ideas that re-envisioned how dinosaurs stood, behaved, etc. Prior to the 1980’s, T-Rex was always depicted as standing upright, with its tail dragging on the ground. Sauropods were depicted living near lakes and swamps, and spent all or part of their time in the water, so buoyancy would help support their weight. As far as feathers go, back in the 1990’s, the only Mesozoic fossil with feathers was Archaeopteryx. China and Mongolia opening up to paleontology expeditions has really advanced the understanding of dinosaurs over the last 30 years. The clear evidence of birds evolving from dinosaurs comes from fossils found in China. The idea dinosaurs might be endothermic wasn’t really considered until Robert Bakker started presenting evidence, in the 1980’s. There was a huge change in dinosaur paleontology, in the 1980’s, that rethought what dinosaurs could be from being fast, rather than lumbering oafs, to endothermic, or to being pack hunters. “Jurassic Park” really leaned into the latest ideas available about dinosaurs.

[@GEOGIRL]

Wow that is so cool, thanks for sharing this information! This makes me like the Jurassic park/world franchise even better than I already did! :D

[@stefanlaskowski6660]

Baker's book, The Dinosaur Heresies, is well worth a read even though it was published decades ago. Baker was ahead of the curve on that topic.

[@gaufrid1956]

As an Aussie it's hard for me to imagine the climate there when it was at the South Pole! Even more so because I live in Mindanao Philippines now which of course is tropical! I'm a big fan of the avian dinosaurs!

[@FlatWorld_Jomhuri_Regime]

Dinosaurs were so successful because Budweiser, hunting rifles, and my cousin Bubba hadn't evolved yet

[@DarthStuticus]

"Well, We Clocked the T-Rex at 32 Miles per hour" - John Hammond

[@GEOGIRL]

OMG haha I don't remember him saying that haha that's funny

[@Soilfood365]

Just a quick aside on brooding; some modern, typically ectothermic reptiles show facultative endothermy - notably some booids will brood their eggs while shivering to generate heat to incubate the eggs.

[@MrBudsyD]

What I am curious about, is, did T Rex have lips, or did they just slink around with their mouths hanging open all the time? You know...drooling.

[@GEOGIRL]

Wow, what an intriguing question! Unfortunately I have no clue haha! Okay, so I just looked it up and google says yes they had lips, but get this, they didn't actually roar! Who knew!

[@darth856]

I have heard that the raptors in Jurassic Park are based on Deinonychus, and that they just used the name Velociraptor because they thought it sounded cooler. Don't know if that's true.

[@TheCadman069]

that hoodie is awesome. thanks for the video!

[@GEOGIRL]

Thanks! :D

[@chriscopeland1318]

Wow, that was fantastic!

[@GEOGIRL]

Thank you! So glad you enjoyed it :D

[@petrfedor1851]

While extinction of non-avian dinosaurs allow mammals to become megafauna most of their extant diversity still lay on shoulders of small animals living in hiding from bigger predators.

[@MadRat70]

Cut your speeds by 75%. The atmosphere in that time period was much more dense and would have been like running through soup. The butterflies were 3 feet long in the time period, if that is any indication of how absolute dense the atmosphere was at the time. This is why such large, long necked dinosaurs could breathe so easily. Weather, on the other hand would have been much more violent through seasons. This suggests the earth didn't have much of a tilt at that time, giving the atmosphere much more relative stability.

[@leechild4655]

I guess dinosaurs were successful because everything around them was successful too. Every living thing thrived it the dino`s enviroment, until it didn`t. Even with a few extinction events, life just bounces back more energetic than before. Amazing.

[@pear-head]

You dont need to pretend to love the Jurassic World movies. It's okay to both love dinosaurs and accept that the Jurassic World movies blow. I mean, who knows, you might actually like the Jurassic World movies. I'm sure someone does...

[@justaguy6100]

In commentary Crichton seems to indicate he was aware of the more appropriate Deinonychus as the choice for the fearsome pack predator of the book, but felt the name "velociraptor" had more punch.

[@GEOGIRL]

Yea, a few people hav commented this now, that is so cool! I'm glad they based it off of something real :D

[@justaguy6100]

@@GEOGIRL I agree. I'll consider it artistic license on his part ;-)

[@johanwise9713]

There is an interesting theory, that many of the small "species" were just the young ones.

[@erictaylor5462]

I thing even a realistically sized V. Raptor would be quite dangerous, especially if it was highly intelligent. Mountain lions are only about waist high on a human but they can easily kill a human.

[@GEOGIRL]

Totally agree!

[@chriswandell3570]

The original reason why Raptors were misrepresented is because they originally were suppose to be Deinonychus when Michael Criton wrote the book. The difference in name came because of a paleontologist by the name of Kirkland who Criton referenced in the 90s the guy was trying to get Deinonychus renamed into I think it was Velociraptor Eorator or something.

[@jasonworks1454]

The second time I watched this video I started tripping on the way you said blood was stored in tubes in the bones @ 11:11'ish into the video. I wasn't paying attention to the part about the blood vessels, and picturing bone marrow. I'm familiar with human bone marrow functions, and got stuck on the word stores. Is the evolution of bone marrow function in extinct/recently extinct animals a thing? Is there a cool name for hematology specific to archeology? I really enjoy the content. I was diagnosed with ADHD during the Reagan administration and was a young earth creationist homeschooled preachers kid. I still have to go back through and relearn biology and science material on a lot of topics simi regularly. Your content and format is greatly appreciated.

[@MWSin1]

Can we all just agree that it would have been more accurate if they had called it Cretaceous Park?

[@GEOGIRL]

ABSOLUTELY! But I must admit I like the sound of Jurassic Park better hahaha

[@nicholasmaude6906]

If you haven't read Dr. Robert Bakker's ( en.wikipedia.org/wiki/Robert_T._Bakker ) excellent book, The Dinosaur Heresies ( en.wikipedia.org/wiki/The_Dinosaur_Heresies ) I recommend reading it even if it's 36 years old. I agree with Dr. Bakker in his book that Birds ( Class Aves ) should be redesignated Dinoaves.

[@tonychinnery]

You say that ectothermic animals cannot raise their body temperatures above the ambient temperature. However many cold blooded animals do maintain their body temperatures above the ambient temperature. For instance many bees are quite furry and they need this insulation to keep in the heat generated by the flight muscles whilest flying.

[@GEOGIRL]

Wow so cool! Thanks for the info, I love when my commenters turn me into learner! :D

[@Ervan80]

great content, thank you so much!

[@GEOGIRL]

Thanks! So glad you like it ;D

[@liamredmill9134]

Apparently oxygen variation's in the atmosphere played a part in how tall dinosaur's got,and the enormous heart involved in pumping up such a volume of blood many stories up played a part in there enormouse size,they probably reached the heights of the tree's ,but we may never know

[@tsmspace]

I wouldn't for to describe dinosaur size in movies as "estimated".

[@prolocutor-for-Jesus-Messiah]

Another classroom quality information video... Great job,,, love the hoody...

[@georgestewart9001]

i love this video its a real good video i enjoyed watching this alot its the best video i have seen thankyou for a real great video

[@phoenix3992]

Oh man.... looks like I was overly critical of Jurassic World: Dominion for portraying dinosaurs in the Italian Alps and Colorado Rockies. Definitely thought they were cold-blooded. Apologies to Chris Pratt, et al. I also thought Laura Dern's petting of a baby Triceratops was silly because I understand mammalian skin as having abundant nerve endings owing to our furry past. But dinosaurs have scales? Ergo fewer nerve endings?? Ergo little stimulation by petting??? Feathers maybe work analogously????

[@mickwilson99]

Re: dinosaurs is paleo-antarctic Australia and Antarctica. Allow that endo-to-exo-thermy would have been a gradient across species, what evidence indicates that mostly-endothermic dinos could not or would not have hibernated? Lizards, frogs, newts and other reptiles quite happily here in southern Canada, where the ground freezes to nearly a metre depth each winter.

[@pukulu]

I remember reading an article in Scientific American, a long time ago, perhaps in the late 1970s, that mentioned all of the evidence that existed at the time for endothermy within dinosaurs. There are some other interesting related questions as well. Given that Plesiosaurs, Pliosaurs, Ichthyosaurs and Mosasaurs were not dinosaurs, it is an independent question to ask which, if any, of those groups were endothermic. A similar question can be asked of the pterosaurs.

[@GEOGIRL]

My guess is, that since the pleisiosaurs, mosasaurs, etc, were true reptiles, they were probably ectothermic, but you're right that is an interesting question to pose. Especially for the pterosaurs, since you would think they'd have to have pretty high metabolism and endurance to fly, now I have to go look it up because you got me curious! haha ;D Ok, I found that pterosaur bone structures indicate they were most likely endothermic, so that makes sense! And I also see that Mosasaurs, plesiosaurs, pliosaurs, and likely ichthyosaurs were all endotherms!! Who knew ;D That is so cool!

[@pukulu]

@@GEOGIRL Maybe endothermy can develop very quickly in evolutionary terms. If so, then all of those extinct creatures might have been warm-blooded. Also, some species of tuna are partially endothermic, along with some species of sharks. Partial endothermy is not well known at all as far as I know.

[@GEOGIRL]

@@pukulu Yea, when researching for this video, I read about partial endothermy. I never even knew that was a thing! But apparently there are some dinosaurs that scientists think were partially endothermic and partially ectothermic which is SO COOL!

[@benclayton6166]

Your vs you're on speed misconception slide. Distracting from otherwise excellent presentation.

[@normangray7869]

Velociraptor: My understanding is that the movie came first. The dinosaur fossil was named after the movie had been out for some years. The story goes that the person naming the fossil thought the movie animal was "cool".

[@_volder]

The name "Velociraptor" was used for actual fossils first, the book second, and the movie third. But their whole family/subfamily as we now know it was in one genus at the time, including the bigger species, and that genus's name was "Velociraptor". Differences among them that would now make multiple separate genera were thought of at the species level at first. (They were pretty new to science back then, based on fewer fossils than we have now and with less time having been spent on studying them, so the internal classification in the group as we have it now hadn't been worked out yet.) So the book started out using the name right, but then changes in the science made it wrong, and the movie was stuck with the book's name choice.

[@dadsonworldwide3238]

It's wild that we dont have many species to point to. Of the ones we know im in the skeptical group on half just being youth or similar family with mild adaptations

[@SiqueScarface]

Every group of animals that manage to thrive for 150 million years is probably doing something right, eh? (I find it interesting how apparently, first the synapsids dominated, being the most successful survivors of the Late Permian mass extinction, then the crocodile-like diapsids took over until the dinosaurs arrived on the scene, outcompeting everyone else on land.)

[@billkallas1762]

I've only been going through your lectures for a handful of days and was wondering if you've discussed the survival of beaked birds, and the extinction of the toothed ones. Why didn't toothed birds evolve back after the K-T event? (Yes, I still use the term K-T instead of K-Pg.....I'm old)

[@GEOGIRL]

I have not, only because I don't currently have any references discussing that specific topic, but maybe if I find some that would be a good future video to do! ;D

[@billkallas1762]

@@GEOGIRL Thanks. When you ask most people what their favorite Dino was, a huge majority will say T-Rex.. My favorite has always been Allosaurus.

[@mhdfrb9971]

I hope next video will talk about Multituberculata, the most successful group of Mammals

[@GEOGIRL]

Ugh! I wish, but unfortunately my references really brush past Multiturbuculata, I mean I mention them in my Cretaceous videos, but not to a great extent becuase my references don't talk much about them, so if you know of any papers, articles, or books that go into more detail about them please let me know! Thanks! ;)

[@toweypat]

Myth: dinosaurs like to sing songs about love and acceptance. Fact: there is no evidence that dinosaurs could sing.

[@c4master703]

I would like to know how a feature like endothermism has evolved. You mentioned semi-warmbloodedness. What does that mean? And did the ability to raise body temperature evolve several times jn different groups of animals? I would be pleased to see a videk on that topic.

[@sarahrosen4985]

Now I will always dream of a dinosaur down comforter…

[@ecurewitz]

Awesome. Thanks

[@eamonahern7495]

Could spinosaurus have been knuckle walkers on their front limbs on land? I was looking at the skeleton of a giant anteater in a video recently and the shape of it combined with the big claws reminded me somewhat of a spinosaurus. Then it showed footage of the anteater moving around and I thought perhaps spinosaurus moved like that when it was on land.

[@maozilla9149]

great video keep it up

[@GEOGIRL]

Thank you! :)

[@maozilla9149]

@@GEOGIRL your welcome

[@gecko-saurus]

Dinosaurs are still reptiles, technically. Unless its a polyphyletic group (like antelopes) or paraphyletic group (like fish), an animal can never change "kinds". Birds will always be theropods, saurischians, dinosaurs, archosaurs, reptiles, sauropsids, tetrapods, vertebrates, chordates, and animals.

[@nuoiptertermer4484]

There's a lot of contradiction you find when you look up when the earliest known mammals lived. I've gotten sources that said 225 million years ago.

[@marksherrill9337]

Wow, this girl is good.

[@SpringIsBACK]

Endurance? Hmmm. A 30 lb. catfish (under 1/5th my mass) can put up a pretty darn good fight for 20-30 minutes, unless you have gear to simply overwhelm it... Granted that a human can run at a modest pace for a long time, but that is putting out on a fraction of its capability at any moment.

[@nw5524]

It's a shame that the name Oviraptor ("egg thief") still applies to those Maniraptoran theropods. We now know that they were exhibiting brooding behavior (as covered in the video at 11:32).

[@GEOGIRL]

Yea, I know right, poor sweet dino mommies!

[@nw5524]

@@GEOGIRL Yes, those fossils are bittersweet discoveries!

[@a.randomjack6661]

Why Dinosaurs Were So Successful? The didn't have politics 😁 Have a nice Sunday Geo Girl, and thank you again✌

[@GEOGIRL]

OMG I can't believe I forgot that reason! lol so true... Although how do we know for sure?? hahaha jk

[@mhdfrb9971]

What's wrong with politics?

[@nyoodmono4681]

poor therapsids they looked so funny

[@reidflemingworldstoughestm1394]

Boy, if I had a nickel for every misconception dinosaurs have....

[@jensphiliphohmann1876]

14:20f: > _so they had frozen to death had they tried to live in such an environment._ Not necessarily. Some modern fish and amphibia can withstand extreme cold unless it's close to perennial, due to natural antifreezes their bodies produce.

[@GEOGIRL]

Ah, so cool! Thanks for this tidbit! ;D

[@martonlerant5672]

Some snakes do brood over their eggs. However aside from said life period they are cold blooded. Its one of those strange cases when reality refuses to seaparate neatly into the two mental boxes we wnated to categorize everything.

[@meleder]

can you put things in kph that is what is current

[@gerardcoyle2587]

Thanks. I have heard though that some paleontologists believe the dinosaurs were in trouble before the asteroid hit, particularly due to their diversity declining for some reason.

[@GEOGIRL]

Yes! Great point! I believe they were as well, I talk about this in my Cretaceous videos because that is the period leading up to that extinction event :)

[@paulohagan3309]

@@GEOGIRL Not trying to start an argument but on another video on dinos I saw, it was argued that at certain times some animal species decline but sometimes then increase in number again and that the declines seen are not indicative of a general decline in dinosaur populations all round? And that therefore it is not certain that they were in trouble before the asteroid struck?

[@GEOGIRL]

@@paulohagan3309 Yea, I totally agree, I think there is some evidence they were, some evidence they weren't and some that points toward some groups in trouble and some fine up until the asteroid hit. I am guessing its the third option, I am no dino expert, so I am sure you are right! ;)

[@pedrohpires6608]

Obrigado!

[@GEOGIRL]

De nada! ;) Obrigado pelo apoio! (I hope google translated that correctly haha)

[@pizzafrenzyman]

at 20 mph, did T-Rex's have enough speed to catch prey, or did they feast on carrion?

[@GEOGIRL]

I believe they still has enough speed to catch prey because not everything was as fast as the velociraptors, I think a lot of the herbivorous dinosaurs or four-legged dinosaurs were much slower and were easily caught by T rex, but that is a great question! I guess the real answer is we will never know for sure ;)

[@johnfcockrell]

Nice comforter.

[@GEOGIRL]

Thanks ;) I am a little sad though because I have one with dinosaurs on it but I forgot to put it out for this video! Oh well, I still love the periodic table!

[@danwylie-sears1134]

"Gastroliths are exactly what they sound like." There speaks someone who parses words correctly. :)

[@gatchrocks]

Dinosaurs went extinct because they were careless. Have you ever seen a dinosaur wearing a helmet when they ride a bike? I didn't think so. They were careless. Always wear your helmet.

[@davidwilkie9551]

Fossil Records and more research techniques, interesting and absorbing science, only now we need to upgrade the orientation required for proper understanding of holography and development of wave-packaging envelopment consistent with Euler's e-Pi-i Superposition-point sync-duration resonance chemistry. This doesn't change the world, it's just doing a better categorization spectrum, eg the Periodic Table is a logarithmic-resonance 2-ness picture-plane containment of states as in book page layers and shows parallel coexistence time-timing sync-duration positioning across time-timing in entangled re-evolution circularity quantization cause-effect from atoms in 2-ness to e-Pi-i 1-0-infinity sync-duration i-reflection ONE-INFINITY Singularity Eternity-now Interval Conception holography.., ie information In-form-ation is Sublimation-Tunnelling Singularity-point superposition in/of QM-TIME Completeness.

[@tsmspace]

well, for over 100 years dimetrodon was a dinosaur, especially in common language, so actually, for a long time, dinosaurs were more reptile like. (not because a big lizard is actually a mammal, but because it looks like a big lizard)

[@GEOGIRL]

Yes, absolutely, for a long time our reconstructions of what we thought dinosaurs looked like and lived like were much more reptile like, but now we know they actually weren't, so our reconstructions of them just got much better :)

[@Hellbender8574]

Another good video. What do you think about dinosaur intelligence, based on inferences from the fossil record? When I was a child, all the experts assumed that dinosaurs were dimwitted as animals go, due to their very tiny brains compared to body size (exemplified by the famously tiny heads of stegosaurus and sauropods). But recently paleontologists questioned that they might have been more intelligent, as more evidence of their behavior is found. Birds such as crows and parrots are smart yet have small brains, as they are built to minimize volume and maximize ability.

[@GEOGIRL]

Well I don't know much about their intelligence, other than the stuff about communication and living in herds and communities that I shared in this video, but it wouldn't surprise me if they were just as smart as many birds today, like crows. I don't know if you listen to the podcast, ologies, but it's one of my fav things! And the host of that podcast had a crow expert on one time and it forever changed my view of crows, now that I know how smart they are! It's amazing :D

[@BigJFindAWay]

Great video. I want to add something else. One of the most annoying things I see on videos of dinosaurs and other prehistoric beasts is that a predator lets out a roar as it charges it’s prey. That’s an insult to the intelligence of viewers. No predator would do that. That would cause your prey to flee or to stampede which could kill the predator. Predators need to be stealthy and sneak up on prey and do the job and quietly and quickly as possible.

[@geodad4782]

I’m pretty sure that the climate was considerably warmer than today all throughout the Mesozoic. That’s what I learned in my university classes. I graduated in 2017, has any new data been found to invalidate what I was taught?

[@wbiro]

I still bemoan the loss of the slow, tail-dragging, Brontosaurus (with the small, walnut-sized brain)...

[@neddyladdy]

Are there only a handful of characteristic features that distinguish dinosaurs from non-dinosaurs?