Where Are All the Medium-Sized Dinosaurs?
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- Опубликовано: 11 авг 2021
- The remains of medium-sized predatory dinosaurs are pretty rare in places where giant predators like T. rex existed. Which is weird, because that’s just not how ecosystems work today.
Thanks to Franz Anthony, Jack Mayer Wood, ABelov2014, Fabrizio De Rossi, Nathan E. Rogers, Emily Willoughby, Julio Lacerda, and Vladimir Rimbala for their wonderful paleoart featured in this episode.
Produced by Complexly for PBS Digital Studios
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I can imagine an adult T-rex trying to catch smaller prey & thinking "I'm too old for this."
😂 I heard this in Danny Glover's voice! 😆
@@becauseimafan You're not the only one. And his buddy emohasizing "We're too old for this $***" in Mel Gibson's voice.
A few studies have shed light on how an adult T. rex may have been able to catch smaller, faster prey. One study showed that chasing a prey animal into water would have given T. rex an advantage. Basically, the drag from the water and the size of the smaller animal would have slowed it down by forcing it to start swimming earlier, whereas T. rex's mass would have counteracted the drag, while it's proportionally longer legs would have allowed it to walk further into the body of water before having to start swimming. Also, it is believed that it had cushioned pads on its feet that would have allowed it to sneak up on prey almost silently.
Crocodilians change niche with age too. Niche changes through a lifecycle would explain why smaller crocodilians species don’t tend to be present alongside large species. E.g. the Nile River doesn’t have a smaller fish specialized crocodile living alongside Nile Crocodiles.
You summed up my thoughts perfectly!
She's saying the juveniles and adults lived in the same area. You're saying the opposite is true of Nile crocs.
@@williamjordan5554 ...that's not what they're saying.
@@williamjordan5554 Read it again
It also helps explain why the dwarf caiman, the smallest crocodilian as an adult is able to coexist with south American crocodiles and breaks the trend, because they tend to hunt on land more than other crocodilians.
Somebody needs to start a band called "Jane and the Cleveland Skull"
This band name slaps so unnecessarily HARD
Apparently "T-Rex" may challenge you on Trademark grounds.
It will be interesting to get a final ruling
Sign me up!
What kind of music? I’m imagining a Runaways-type all-girl group
Nicknamed “JatCK” !
the longer legs on the juvenile Rex made me think of horses and the way their legs are when they're foals. There's a reason the word is "coltish," haha!
This also makes me imagine young Rexes scampering around and playing, sharpening their hunting strategies on unsuspecting shrubs.
Gotta love when the science also prompts us to envision incredible predators as cute babies!
Now I'm picturing some knobby-kneed week-old rexes playing together in a clearing, while their full-grown momma lies prone keeping watch.
Omg that's such a cute image, why have you done this to me???
Even cuter, t rex likely had feathers or fuzz, so a baby t rex would be a clumsy, fuzzy fluff bird attacking shrubs as hunting practice.
Super cute, six-metre long killing machines.
@@origaminosferatu3357 Feeling cute, might eat some composognathus, IDK
The shaking ground stirs ripples in a puddle.
5 meters the other direction, a juvenile T-Rex is trying to psych out a fern by staring it down, snorting (sneezing) and making erratic bouncing flails. It occasionally bolts behind a tree when it's bluff is called.
I'm guessing it also takes a lot of juvenile T-rexes to have enough to make it to adulthood. Being a predator is quite perilous. Injury often means death.
If they worked in tandem with each other as a pack, maybe not. Doesn't have to be a big pack; 3 rex with one of them being a big old one would be enough to keep them all fed and reduce the threat of injury.
@@Kalebfenoir is that behavior reflected in the fossil record when it comes to being a T. Rex?
Kalebfenoir
In any stable population only two offspring from any breeding pair will grow up to become a member of a breeding pair. If an adult female lays only 10 eggs in her lifetime, 80% of her offspring will die before reaching breeding age. The more eggs she lays, the worse the odds get for any of her individual offspring.
@@donsample1002 populations are never stable!
@@donsample1002 As apposed to rapidly fluctuating populations. In nature rabbits routinely undergo population explosions before suffering massive collapses as disease, famine, and predators that migrate in from surrounding areas to partake of the feast crash their numbers. Of course, predators tend to have more stable and slower breading populations than their prey.
The Burpee Museum of Natural History, where Jane is on display, is less than 20 minutes drive from where I grew up. I always forget that she's kind of an important specimen...
same! we were more like 30 minutes away, but my mom used to take me there on my birthday every year :( i miss jane
Wow nice xD I wish I can visit and see it by myself
Lol, Burpee
Grew up just north of Rockford - had no idea this was at the Burpee, although I went there as a child. Cool!
In kindergarten and 4th grade we went on field trips the the Burpee Museum. They have Jane but also many other cool fossils!
One preservation bias question I’ve always had: since many fossil sites tend to be former river valleys, coasts, and lowlands, what did high altitude/craggy mountain dinosaurs look like?
Sean Connery?
probably few and similar to some of the smaller cold weather ones would be my guess if they did exist.
My guess would be that they are smaller than their lowland counterparts. That way they or their herds could more easily maneuver in tight spots and jump if needed.
Mountain goats with long fat lizard tails.
They had wings and breathed fire, obviously :-)
When T. rex is so op it simultaneously dominates nearly every land predator niche.
Truly the greatest predator this planet has ever seen until humans evolved
@@hyd3n376 yes and no. I'd argue orcas have overall been more successful
@@vincenzocapasso9990
“Orcas body seals for fun” -hood nature
@@penguinsrockrgr8yt216
“We enslave them for fun”
-me, 3 seconds ago
@@Toasteeei lol I don't think that's true. Orcas tolerate humans. They r incredibly smart, probably the second most smartest species after apes.
Theropods: “Can I be a medium sized carnivore please?”
Evolution: “Alright, crazy and unrecognizable puberty, got it!”
Theropods: “….”
Best comment ever!! 😂😂😂😂😂
Wow this meme is a living fossil!
They tried to put Jane on the cover of cretaceous weekly, but her legs were too long
Dude, she's 13...
@@paulprasek1475 FBI open up
@@paulprasek1475 she's at least 65 million and likely quite a bit older. That's definitely old enough that she can make her own choices!
@@Kobolds_in_a_trenchcoat better get her consent first!
@@Kobolds_in_a_trenchcoat shes 13 and been dead for over 65 million years. Doesn't exactly help your case...
Generational competition is also why metamorphosis evolved in insects. This could be evidence that many dinosaurs didn't raise their young past hatching, or share food.
Possibly! Or that if they did hunt it was with different methods than we normally see. Such as young ones flushing prey to waiting adults… which would be terrifying. If we don’t have records of bite marks from young ones on small prey maybe that could also be further proof? Or maybe they didn’t bother with bones?
Not necessarily, because it's still entirely possible they supported their young when they were at their smallest, but then the young went off on their own when they could reasonably fend for themselves.
@@sampagano205 Possibly a mix of the two theories.
Or even worse; what if they formed intergenerational packs? Young individuals for harassment and driving, old individuals for killing blows. Such behaviour has been spotted among saltwater crocs.
Could also be something we don't see in living animals - like the adults and their offspring sharing a range until the offspring got big enough to take a range for themselves - or even family groups co-operating to secure a larger territory, even if within that territory each individual basically lived an independent life. Plenty of really cool options.
"Sit and wait carnivores, who prefer to hang out and let food to come to them."
I too employ this method to great success. Let the burritos come to me
Ah, to watch the great burrito migrations across the plains in days of yore.
Yes. Years ago, I used to actively pursue burritos. But now, I'd _much_ rather they just come to me. :)
Jabba The Hutt.
This probably also explains the limited diversity of medium-sized herbivores in sauropod-dominated environments. The young sauropods would fill different niches than the gigantic adults.
If the theory that the young lived on their own is true then it actually makes sense
I think there is some evidence of camarasaurus eggs that seem to not have been placed carefully in a certain shape like eggs in nests of animals that care about their young do they are placed more randomly so I think this indicates that this is true
And the young of things like Dryosaurus might have occupied the niches of very small mammals and reptiles.
Biggest thing it explains for me is why all non avian dinos went extinct and mammals survived. Dinos basically monopolized all niches and if some disaster happens whole genus is eradicated.
Think about all the small species that aren't dinosaurs that lived in this period. There could be a lot of them.
@@muradm7748 Ironic
Not only komodo dragons, water monitors get quite big and their offspring do the same, they climb trees extremely well and eat different stuff like bugs.
This is also true of Tegus and many other lizards that get large enough that they are able to primarily live on vertebrate prey.
@@sampagano205 Also fish, sharks... amphibians and insects are the most extreme example of occupying very different niches but they go through a metamorphosis so it's not a fair comparison.
Monitors also do this to avoid getting predated upon by larger members of their own species. It may have been that in the territories of larger T Rexes, juveniles would try to avoid it. I’d envision large T Rexes occupied heavily forested land to better ambush their large prey, while juveniles worked more open land where a prolonged chase is more likely. I’d also expect more Komodo dragon style feeding, where smaller juveniles share a kill until the large adults chase them off it.
I loved seeing a show monitor. Once he was done with his show, he had this sassy prance back to his pool… with a GLORIOUS belly-flop, and soaking everyone nearby!
I’m now imagining a sassy, lanky teenage t-rex.
“Hey, dad, bet I can beat you to that tree.”
“I will literally bite your head off of you try.”
“But I’m your son.”
“I can make more of you.”
"you won't"
"Why do you think your name's Six?"
“You know what? I can just start over and make another kid. It’ll only take seventeen years, right? Think, Mark…THINK!!!”
I am imagining a dark and gritty reboot of The Land Before Time.
@@michaelnewton1332 I understood that reference.
The occupation of multiple niches by a single species throughout its ontogeny might have rendered them more vulnerable to extinction, since there were more possible "points of failure".
I read that a similar thing happened with sauropods; there was no way the little babies could be cared by their massive and tiny brained parents once born, and they were too defenseless to roam the open plains, so they probably were forest dwellers in their early years that joined the herds of open range giants until their adolescence, when they grew too large for the forests that had sheltered them early on.
I’m guessing you watched walking with dinosaurs
Omg flashbacks to watching Walking with Dinosaurs.
Trackway evidence undermines this argument because you see plenty of sauropod herds that include a wide variety of age groups. Meaning they probably did live in family groups.
@@sampagano205 As I understand it, we have evidence of both when it comes to sauropods: trackway evidence supports that some species had age-segregated herds, while others contained multiple individuals of different ages. What exactly caused these difference probably isn't known, but both strategies were used by sauropods.
@@Vesmir789 yeah. But the person here is saying that there's no way sauropods could provide any kind of parental care. Which is what's wrong. There might have been truly completely precocial suaropods at some point, but it's not out of a lack of capacity for parental care.
What an amazing animal able to dominate multiple niches over its lifetime.
how did u watch it so fast
It's actually quite common though; just not with mammals...which they compared to dinosaurs for some reason.
Eg. Young sharks and birds will prey on smaller things (fish instead of seals, mice instead rabbits) than the adults, and often in different areas as well.
@@LENZ5369 and then there's us. no vegetables as children, and then only the finest French cuisine as adults
@@LENZ5369 I really don't get the trope of trying to understand the behaviour and ecology of dinosaurs through the lens of mammalian behaviour and ecology. Animals with entirely different biologies in entirely different environments are just not good analogies to each other.
@@LENZ5369 Except the size discrepancy between adult birds and hatchlings isn't as vast. They also mature quickly. Sharks and some reptiles are a good analogue though.
Any episode about dinosaurs is a good episode :)
Truer words have never been spoken.
But all the other episodes are good, too :)
....and the illustrations were great.
Truuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu
Any episode -about dinosaurs- is a good episode :)
I remember reading an article that suggested that even before the KT event Dinosaurs as a whole were suffering from the beginnings of a decline based on genetic stagnation. I wonder if that was connected to singular species dominating multiple niches across their ecosystems and basically outcompeting genetic diversity. Hard to maintain a good evolutionary turn-over when most of your niches a filled by a single species at different growth stages.
Were dinosaurs so good that they had started to outcompete themselves?
Most specialized animals have the biggest problems when a mass extinction comes tiny stuff that are not specifically specialized for one thing are the ones who make it through
But yea it might be the reason you say too
"There were no medium-sized predatory dinosaurs in Hell Creek."
Dakotaraptor: Am I a joke to you?
Dakotaraptor is possibly a chimera.
@@rathsmack1334 Nope. The wishbone turned out to be turtle shell, but the species is still valid.
@@alecfoisy58 you sure about that
@@morewi Yup. The validity of Dakotaraptor has not been questioned anywhere in the scientific literature.
@@alecfoisy58 but they managed to confuse a turtle shell for a dinosaur bone? How many examples of this creature is there
And I was totally happy to help out!!
🤩🤩
Admirable, but it's a bit late to fill the role of a medium dino...
@@dangerfly ?
@@dangerfly Ha!! (And I am trying to avoid being between 100 and 1000 kg!)
YOU'RE ON RUclips!!
This was the most science heavy episode ever. I might not understand it but I appreciate it
"Jane and the Cleveland Skull" would make an amazing band name.
Doesn't matter if I am a kid or an adult, I am in awe imagining what an awesome, thunderous site a T-rex v. Triceratops battle would have been like.
Closest thing we got to it today is sperm whales versus giant or colossal squid and that’s hard to get on camera. I’m pretty sure the last time I checked we’ve never gotten the fight on camera. I could be wrong though maybe in the years since we have. Still pretty cool.
North America? Probably a whole lot of paper work.
What if T-Rex was just a scavenger, so the "fight" really sucked?
@@that1valentian769 Giant exothermic, oxygen-breathing apex predator with active sonar and a biological directed energy stun gun, versus significantly smaller, cold-blooded slow-moving invertebrate that's specifically specialized for the low-oxygen and low-power/calorie deep sea?
You'll never imagine it in full detail. Don't waste your time
Here we were thinking Steve was his own unique species.. turns out he was simply the juvenile version of Patrick Seifert! ;) (A)
Did we ever confirm he’s ok?
Maybe the PBS EONS team can reach out to him and tell him we miss him and that we hope he is doing okay? :)
I miss Steve
7:08 man the distant sound effects of heavy footsteps and roars gave me chills, what an incredible group of animals.
The title is somewhat misleading. It should be more like, "Where are the Hell Creek's Medium-sized Predators?". We have plenty of "mid-sized" dinos from around the world and in all parts of the Mesozoic.
They're there. You just gotta ask for a grande or a venti dinosaur.
I applaud you!
But venti is large 🤣
They all had to fear the trenta dinos tho
Animal style dinos
Ah yes Starbucks, so brainless they just have "large" coffees in 3 different languages and no one has a problem with that.
Shame they completely forgot about Dakotaraptor, the actual medium size predator of the Hell Creek formation. It would've been interesting because it would've implied that juvenile T.Rexes might've competed with them for similar resources because they occupied roughly the same ecological niche.
Problem is Dakotaraptor is a bit controversial. There isn't a lot of material of it, and it's not easily accessed for further study. Worst of all, it's not at all apparent that portions of it's skeleton even belong to it, for example it's possible the limbs belong to a caenagnathid. I'd imagine this could be why they didn't mention it.
Even if Dakotaraptor, wasn’t large there was still Anzu, A large caenagnathid that lived in the hell creek, i’d imagine it be big enough to pray on smaller dinosaurs, but it might also been an omnivore
@@Monolopho So it might be chimaeric? Damn, that's ashame.
@@Monolopho Although the presence of the large sickle claw already implies that at least a large dromaeosaurid existed in Hell Creek during the Maastrichian. I just hope the other parts of the skeleton actually belonged to it
@@giagarex I think medium refers to predators of 1-2 tons
Can we have a video on how the brain evolved? Like how nervous systems developed? That would be so cool!
This was one of my favourite of your recent episodes! Makes me interested in an episode about baby dinosaur discoveries if that's something you'd all be interested in making!
I get a large dose of happiness whenever a new upload is in my feed.
You mean a large bite of happiness
I guess you get a large dose of happiness a lot
Something grows when i see a host that looks like that on a video.
This is another one of those episodes that is really funny to me when looking back on when I used to read Young Earth type crud. For all their adamance on the age of the earth, they’re VERY willing to play around with different ideas for the fossil record, and this is one of them they brought up: that some of our fossils aren’t unique species, but the same species at a different stage of life
Of course, they still ran off with the idea WAY farther than they should have, but it’s still funny to me
I feel that, even a blind squirrel finds a nut huh?
how did it run off too far? this have been a theory for years now and would make sense? look at any fauna in most eras and its not like there are a million species that are at the top anyhow.
Wait is this true? Have scientists come on board with biblical truth now?
@Atheos B. Sapien yes that’s what he meant.
@@HkFinn83 what
Heyyyy I took one of professor Holtz's classes at UMD. Great guy, his lectures have amazing energy!
I agree, and my main theory for why the young t-rex was a marathon runner was mostly to escape older t-rex.
Saw a video about this years ago, not exactly this but similar situation (was about the Dracorex hogwartsia)... the guy in that video who himself was a paleontologist summed the problem up with, "they like naming things", you find a skeleton that isnt X or Y but something similar and inbetween, you call it something new since hey you get to name some new species and attach your name to that discovery.
ie Ego takes over rather than science.
Problem is dinos are bird relatives and their bones have stages of growth like birds can exhibit, alot of the small dinos in some species like Triceratops appear to have the younger type of bone compared to the larger ones, meaning the large number of Triceratops species are probably just different stages of growth and age within the species. ie Dinos probably over a single lifetime morphed radically from birth to final adulthood, some even changing from young to teen to adult in such a way that you'd swear they arent even the same species.
But hey... that would mean alot of people no longer get to say, i discovered that dino species, and Ego is a hell of a drug, especially in a science field where new discoveries arent all that common. But it would explain why you get a lot of 'adult' dinos but virtually never find babies and juveniles that look like most of them. Unfortunately, this idea has got quite alot of resistance to it in the field or at least used to in the past from what I gather, which is disappointing.
Are you thinking of Dr. Jack Horner? I believe I watched the same lecture, it was him.
Was that Jack Horner? Pretty ironic coming from him.
Teenage Tyrannosaurs filling the niche of medium size predators in late Cretaceous North America might explain why the only other large terrestrial predators were hunting small to medium sized prey. Those being the dromaeosaur Dakotaraptor, the troodontid Pectinodon, the Komodo dragon-like lizard Palaeosaniwa & the azhdarchoid pterosaurs like Quetzalcoatlus & possibly Wellnhopterus/Javelinadactylus.
Interesting that Camarasaurus was mentioned as it lived in the Morrison formation (Jurassic) eco-system which unlike the Hell Creek one (Cretaceous) *did* have medium-sized carnivores like Ceratosaurus as well as large ones like Allosaurus.
This does suggest an interesting shift in how these animals and their niche partitioning evolved over time.
So non avian dinosaurs went through more radical changes in their growth stages than mammals?! PBS Eons you always teach me something new!
Do a video on the Cretaceous Green Revolution please!
this is a theory I do not think its wrong but do take it with a grain of salt. We are talking about creatures that lived 65 million years ago or more. I honestly think as a predator you would need to change as you grew to adapt to hunting new prey same for the herbivores but we cannot know.
considering the likely behavior tyrannosaurs had when it came to their young, it makes sense that they had very different lifestyles and diets.
what behaviour? There are plenty of theories about them some saying they formed packs and hunted together and some not. so tell me the one you believe in ^^
May as well reply to this…
Tyrants (and other large theropods) probably left their young to fend for themselves after they got larger than many local predators, specifically those of other species. For tyrannosaurus, I’d assume Jane (around 2m tall, halfish adult size) was recently kicked out.
And, even if the pack theories are true for other tyrants, tyrannosaurus might not have hunted in that way, or at least, not with its own kids. Daspletosaurus, being significantly smaller, would have had a lot less time to grow so the kids could start hunting large prey much earlier.
The answer to a question I never knew I had!
I'm very happy you use the metric system and still provide feet measurement. Both needs are filled without breaking/disturbing the discussion of the video.
This was a great video! Everything was really easy to understand thanks to an accessible yet precise presentation of the information
Great video. This is a very interesting topic to understand ecology better. Though I think the discussion is missing Dakotaraptor as an integral part.
Dakotarapto's size is not clear since we only have a few bones and proportions aren't fully understood. Also note, juvenile T-rex has been more regularly found and were generally larger, so they were clearly the primary mid-sized predator in the ecosystem with Dakota being a rare exception.
(This could be because they were safeguarded by their parents, making it hard to compete with them)
@@reubencaldwell8494 I mean, I think there is a consensus that Dakotaraptor was a mid-sized predator (in comparison to dinosaurs).
And I think it's hard to get to the definite conclusion of Juvy rexes being the primary mid predator without assuming many other characteristics. Like, as you mentioned, the intraspecies socialization, as we aren't sure if they were solitary, paired, packs, etc.
They might not have brought up Dakotaraptor since its validity is being brought up to question and it might end up being a chimera iirc
Additionally, DePalma, the person who discovered Dakotaraptor, has some questionable work
I remember reading a theory that, because the adult Rex were so big, and they couldn't run full-tilt because of their weight and size, the younger rexes that were smaller and more nimble would act as pack-hounds, potentially herding a larger prey animal close to where the big Rex was, whereupon the big Rex would basically turn a corner around a tree or a bush or something like that, and kill whatever the animal was. And then everyone would have a share in the meal. It wasn't that the big rex were carrion feeders, but that they could require their siblings/offspring to work in tandem with them to bring down difficult to catch prey. I always thought that was interesting, and it still makes sense to me. It'd result in the smaller rexes (rexii?) getting a nice big share of meat if they coaxed a large beast into the path of the Big Rex, and the Big Rex could save its stamina and strength for the killstrike and whatever short chase it had to do to achieve it.
I remember when that theory was proposed. I thought it was kind of ridiculous because the adults would need to always have juveniles around in order to eat. I prefer this theory that juveniles just filled the niche of medium sized carnivores.
@@infinitemonkey917 yeah it could be totally bunk. Not like we're gonna know unless someone magically jumps back to their time and records them. Or someone stupidly makes JP a real thing. Lol.
@@infinitemonkey917 That would be like assuming male lions would need a pride to do the same for them. But male lions are perfectly capable of hunting on their own (and do so even in a pride, we just don't observe it much). Just because something is more efficient, doesn't mean it is a requirement.
I was thinking of that during the video. Kinda like lions - females do most of the hunting, whilst males protect the pride and sometimes do the heavy lifting.
@@UnintentionalSubmarine But adult females lions do most of the hunting, not juveniles. So how is that remotely similar ? Also, a male lion without his harem / pride is in a bad situation. Juvenile males hunt together but a lone adult is in a precarious situation often leading to death.
This was a genuinely interesting episode!! Admittedly I only ever thought of the adults, so thinking about them growing up makes them feel less like fantasy!
Wow such a great video! Short but still very informative! Its fascinating how different a dinosaur life was!
Fascinating! You present a mystery I didn't know existed, then solved it in one episode. Great stuff! FWIW I live about a mile from The Museum of the Rockies in Bozeman and have spent a lot of time wandering the dino section!🐉
Great video. Love the last explanation of why Nanotyrannus doesn’t make much sense.
Fantastic as usual Eon. Appreciated as always.
Thats a great concept! My mind grew a bit after this video
Evolution really knocked it out of the park with T-Rex.
Such a cool video! I’ve heard of the niche shifts hypothesis, but seeing it explained in such a well thought out video was an incredible treat. Thank you so much!
Seen this before, but loved watching it again, it's a bloody masterpiece, great reaction. I hope you get to see them as they're touring again now. I can't believe I'm off to watch them myself in Sydney, never thought it would happen.
The way the matter is slowly explained i.e.the speed of talking was good for my understanding
Loved the episode,keep going...
So basically Tyrannosaurus was a Pokemon
T-rex,I choose you!
@@e.ggamerguy5793 so Tyrantrum
I'm going to assume it's a combination of "go big or go home" and something to do with nature of probability of fossilization.
Oh! That is pretty neat. That is true that the size differences between adolescent trex and adult trex is so vast that the could fit a myriad of ecological niches through their life spans. And that's also ontop of probabilities of them actually getting to adulthood might feed into this aswell.
wrong
That was fascinating.
I love that we see new and different things as our perspective changes. We were looking at dinosaurs as being similar to us but when we decided to observe them from a more lizzard perspective, we see many amazing new possibilities into how they lived and their ecosystem..
Great episode! I love anything you do about dinosaurs.
Ontogenetic niche shifting, I’ll have to remember that one. Very interesting. Great episode!
Doesn't the same thing happen with corals? The young are free swimming and hunt plankton, while the adults hunker down in place on reefs.
This parallels eerily to Spinosaurus and Sigilmassasaurus in Morocco.
It's highly likely that those two are synonyms.
Very cool video, always interesting to hear how theories about dinosaurs are evolving.
It makes me wonder, With such dramatic changes how do you tell if a discovery is a new fossil or variation of an older one. So interesting. I love it.
Bloody hell 64'000 Newtons is like the thrust force from a small turbofan!
t.rex goes chomp really hard lmo
Interesting theory.👏although the video (and research I guess) were all t rex and it's environment focused. Would love to see the results of the same analysis done in different locations at different times with other large predators.
Nice call out at the end! ITs overlooked so much and generally nothing is ever done about it. So thanks for pointing it out.
Very intriguing and fascinating!
"Bottom line: growing up is hard."
Amen
i guess you can say...
their medium - rare
@@negativeindustrial You're not. The comment only got posted 10 minutes ago so be patient.
*they're
This was fascinating, thank you.
These videos are always great!
Niche partitioning within a species. Neat
Omg that baby komodo dragon is so cuuuuuute!!
This was fascinating. Appreciate the details.
I'm so glad people are interested to study this subject so thoroughly and present it in this neat tl;ds (s=study)
I love the new host! She is great and I loved the topic!
....but in stead of calling it the "Carnivore Gap" what if it was called the "CarniVoid"?
The upload i was waiting for!
Edit: I was fascinated by this study, i always thought that juvenile T rex hunted or accompanied adults learning by their side either by observation or contributing by surprising the prey guiding it to run into the ambush laid by adults for them to deliver a fatal bite. Although this may have happened when they reached a decent size and age as there are alot of theories and fossil sites that indicate these majestic animals did live in packs and solitary as well. But still the occupation of different niches sounds perfect for younglings learning by instincts while honing their skills by hunting smaller prey. Better that way because staying away from niches of adults is a good strategy to survive cannibalism. Such a magnificent species and so interesting no wonder it has been the focus of all Hollywood dino movies.
This was a well studied and perfect upload PBS i hope you focus more on the behavior of these animals further in future as it's always a joy to watch your team cover it. Thank you! 👍
Love the soothing music in the video makes the dinosaurs so majestic 💜💜💜
Shout out to Cleveland museum of natural history, by far the best history museum in northeast Ohio.
Not far from where I live
Grew up hanging around that museum, they also have Balto!
Is that still a compliment? 😂
Grew up with that Museum, and eventually worked there for a spell. There's a great episode of Infinite Voyage (A Nova-esque program from WQED Pittsburgh) called "The Great Dinosaur Hunt" that also features Cleveland and the Cleveland Skull. Robert Bakker talks about it at length. It's pretty great.
What about Dakotaraptor? A medium sized carnivore from the hell creek formation
Exceedingly rare. Only a few specimens have been found, and only from the very last part of the Hell Creek. It doesn't appear to have been a common part of the ecosystem, at least for most of that history.
Actually, it’s technically a small sized carnivore, and they were probably up in the trees (if the theory about gliding raptors is to be considered).
Dakotaraptor is rarely represented in Hell Creek and was probably being outcompeted by subadult and even grown Tyrannosaurus. Like Thomas RIchard Holtz said, its place in Hell Creek was quite niche.
@@silvertheelf Dakotarapror is like taller than a human, and the length of a small car. There's no way that beast would be able to glide from tree to tree XD
@@silvertheelf what?! No lol. Dakota was moderately sized but like Holtz said it’s extremely rare
excellent episode!
There seems to be a lot of evidence for dramatic changes in bone shape among all sorts of dinosaurs and such, as they grow, to the extent that young and old were often mistaken for different species -- and this is a perfect demonstration of why they would have needed such changes. Excellent video.
its so funny to me how scientists label specific fossils with random names like youd expect some weird code name like TR42F3 but youve just got susan and joanne
Actually they still have catalogue numbers. The names are nicknames
Michelle’s voice is so calming. Listening to them talk is helping distract me from my jaw pain because I got my wisdom teeth out lol
when did they join the PBS Eons family!? Last I remember, Hank & the SciShow Space bald guy plus the witty blonde lady hosted most of the videos
@@AifDaimon This is Michelle’s first time hosting by themself. They were in a recent video where all of the hosts were there. I don’t believe the scishow guy still does PBS Eons. Also I believe Michelle uses they/them pronouns, but I could be incorrect
Super sweet representation of the Summerville Formation (and maybe a little Curtis Formation) at 2:39! Probably not too far from where I live.
Awesome! Can you please do an episode on insects? Also, more on crocodillians! Love, Ellison!
Genuine question; could the mini t-rexes be the result of dwarfism? Has that been taken into account, if it's possible at all? Like, not a separate species of dwarf dino's, but just an accidental genetic mishap that resulted in a dwarf t-rex.
What about Dakotaraptor? That's a medium sized theropod that lived alongside T-rex
I get where you’re coming from but recently Dakotaraptor’s validity Has been challenged as some parts of the skeleton look like you don’t even belong to it
I’m obsessed with this channel.
Paleontology is crazy - so many puzzles still to solve and so many academic and practical disciplines involved .
Great so hear someone on RUclips pronouncing "niche" correctly as well!
Im so mindblown now! That was mad interesting
The theory is that, dino herbivores were mostly on the larger side so carnivorous dinosaurs were either really tiny (those that hunts smaller preys such as mammals, insects and fish) or really humongous like the infamous T-Rex which hunts very large preys.
The juveniles filled out the role of the medium sized carnivores that would be taken care of by their parents until adolescent.
This is the theory as to why there are no "medium sized" carnivorous dinosaurs.
Yeah but herbivores too would have been small at one time. And there seems to have quite a reduction in population, as most nests contains one or two dozens of eggs, and that would probably for each female each year or one every two years, for a certain amount of time. So probably hundreds of baby dino in surplus 😁
@@krankarvolund7771 there was no need of medium sized carnivores because that niche was already filled out by the adolescent carnivores. Smaller predators(e.g Compsognathus) were perfectly adapted to eating smaller preys like insects, fish and our mammalian ancestors. Adolescent juveniles were perfectly suited to take down juvenile herbivores. Fully grown Carnivores are more suited to take down the bigger preys. Hence, medium sized predators didn't happen to be because there was no niche for them to fill. Evolution decided that was that and it was working and it was good.
Great vid. Really interesting.
I like that theory about a same species occupying 2 or more niches throughout it life, it's kind of elegant.
Tarbosaurus juveniles did that as well
The meta is clear, you either go big enough to tank everything while needing a lot of food or go small enough to dodge everything while needing little food
man T rexes were toxic back then
@@TicoHyuuga mfs were playing casual as if it was ranked, ruining everyone's game
Moderation in all things
"Better sprinter and more agile than a grown Tyrannosaurus."
So. Just like humans then.
This is SOOO fascinating!!!! Cant wait to share this with people interested (or not (!)) in dinos!!!
Such an interesting episode! That’s actually pretty epic that T. Rex was so well adapted to its environment that it was able to occupy two niches at once based on age. Obviously evolution is not intentional but this is a genius strategy!