Could Theropods Survive the Cenozoic? | North America

[@TheVividen]

REFERENCES Testing Clovis spears on elephants www.jstor.org/stable/280681 How dangerous grizzlies were to pre-gun cultures hughglass.org/grizzly-in-1800s/ Clovis mammoth kill site count www.sciencedirect.com/science/article/abs/pii/S1040618207003771?via%3Dihub Size of the American Lion www.tandfonline.com/doi/abs/10.1671/039.029.0314 20,000 year old human footprints news.berkeley.edu/2023/10/05/tests-confirm-humans-tramped-around-north-america-more-than-20-000-years-ago Ideal migration pathways around.uoregon.edu/content/new-data-suggests-timeline-arrival-first-americans Cooper’s Ferry archaeological site may be older than Clovis www.science.org/content/article/first-people-americas-came-sea-ancient-tools-unearthed-idaho-river-suggest North American agriculture esajournals.onlinelibrary.wiley.com/doi/full/10.1890/ES10-00098.1 Larramendi 2015 www.app.pan.pl/archive/published/app61/app001362014.pdf Hwange National Park lion pride specializes in killing elephants www.researchgate.net/figure/Age-class-distribution-of-elephants-observed-being-killed-by-lions-from-1993-to-1996_fig1_232693088 Elephant matriarchs will charge lions even if the lions aren’t attacking kzbin.info/www/bejne/iabOaaJmds97g7M Elephants become depressed if relatives die books.google.com/books?id=7JIAt-yfIJgC&pg=PA72#v=onepage&q&f=false Information about elephants in musth www.elephantvoices.org/elephant-ethogram/ethogram-table/behavior?id=159 Elephant tusk durability kzbin.info/www/bejne/gJ20fqWsl9l0btE Elephant skull structure is light and honeycombed knysnaelephantpark.co.za/skeleton-skull/ Bulls fighting may break their tusks www.pbs.org/edens/etosha/elephant.htm#:~:text=When%20competing%20for%20mates%2C%20male,tusks%20than%20their%20calmer%20counterparts Bulls fighting kzbin.info/www/bejne/aImkZJedf851ipI Bulls fighting more kzbin.info/www/bejne/gaGxXoNnhLutopY Lions hunting elephants kzbin.info/www/bejne/aJ24aXuZra50rZo kzbin.info/www/bejne/rmXReGeAqKasgbs kzbin.info/www/bejne/hXKTeYSthtV2eNU blog.londolozi.com/2020/03/30/how-do-elephants-respond-to-leopards-and-lions/ Tyrannosaurus bite force peerj.com/articles/13731/ Tyrannosaurus biting Triceratops facial horns www.myfossil.org/featured-fossil-triceratops-vs-tyrannosaurus Elephant birth rate spana.org/blog/elephant-pregnancy-facts/#:~:text=Elephants%20give%20birth%20around%20every,five%20babies%20during%20their%20lives Elephant agility demonstration kzbin.infoVdL8FtN_Lao Teratophoneus gregariousness peerj.com/articles/11013/ Canadian tyrannosaur trackways www.theguardian.com/science/2014/jul/23/tyrannosaurs-hunted-packs-tracks-canada Giant ground sloth body size link.springer.com/article/10.1007/s10021-005-0076-8 Egg stealers during the time of the dinosaurs www.smithsonianmag.com/science-nature/scrambled-eggs-and-the-demise-of-the-dinosaurs-85969406/ Mammals weren’t outcompeting dinosaurs www.nature.com/articles/ncomms1815 Success of crocodilians despite mammalian interference www.researchgate.net/publication/259450979_The_Role_of_Predation_in_Shaping_Crocodilian_Natural_History Nest guarding is likely a basal archosaurian trait defenders.org/wildlife/american-crocodile-and-alligator#:~:text=Roughly%201.25%20million%20alligators%20live,females%20will%20defend%20prime%20territory Collaborative hunting by crocodilians www.researchgate.net/publication/272369202_Apparent_coordination_and_collaboration_in_cooperatively_hunting_crocodilians Paleocene temperature www.scotese.com/paleocen.htm Paleocene environment www.pbs.org/wgbh/evolution/change/deeptime/cenozo.html#:~:text=Ferns%2C%20horsetails%2C%20and%20shrubby%20flowering,America%2C%20Africa%2C%20and%20Australia. Eocene environment cdnsciencepub.com/doi/10.1139/cjes-2016-0043#:~:text=The%20Eocene%20Epoch%20is%20well,as%20well%20as%20to%20climatologists Eocene environment ucmp.berkeley.edu/tertiary/eocene.php Oligocene environment www.pnas.org/doi/10.1073/pnas.2003914117#:~:text=Oligocene%20GMSTs%20were%20%E2%88%BC22,42%2C%2069 Oligocene environment ucmp.berkeley.edu/tertiary/oligocene.php Oligocene ice sheets www.nature.com/articles/s41561-022-01025-x Miocene temperature bolin.su.se/data/miocene-temperature-portal Miocene environment chooser.crossref.org/?doi=10.2307%2F3515337 Miocene migration of muroids to North America academic.oup.com/sysbio/article/62/6/837/1710000?login=false Pliocene temperature www.nature.com/articles/s41598-020-67154-8#:~:text=The%20Pliocene%20Epoch%20(2.588%20to,and%20Antarctic%20ice%20sheets2. Pleistocene extinctions and environment www.nature.com/articles/s41467-020-16502-3 Hell Creek temperature www.researchgate.net/publication/279980306_A_florule_from_the_base_of_the_Hell_Creek_Formation_in_the_type_area_of_eastern_Montana_Implications_for_vegetation_and_climate

[@PREHISTORIC.PRESIDENT.]

There’s a new 3d study that puts trex bite at “18,000 21,000”psi and T. rex average Weight estimates 10tons-and kg and tons are different just to let you know love the vids❤

[@landenriley8442]

I think Carcharadontosauroids like Gigantosaurus would go for the lone male rather than the whole herd

[@tyrannotherium7873]

Actually, it’s implying that American lions are lions after all

[@Ratchetcomand]

I wish you had Dilophosaurus to the roster in the video

[@ЕрсултанСапаргали-ц3ь]

Hey,you can make video about theoretical maximum height from ground to head for tallest sauropods including Sauroposeidon

[@charizardfan1017]

I personally prefer the idea of calling a group of Tyrannosaurus a "Royalty" Cause they're the "Tyrant Lizard Kings"

[@biohazard724]

I'm partial to a "Castle"

[@wildbill9490]

I believe a group of tyrannosaurs is actually called a terror

[@adhdproductions1851]

A monarchy

[@johnburnett8625]

A "Kingdom" would be my preference.

[@Clovernoris]

A Court of Rexes maybe?

[@HolyCanolei]

I googled it, and apparently a group of tyrannosaurs is called a “terror”, which I think is solid.

[@ottovonbismarck7646]

I mean... I would be in a pure state of terror if I saw a group of some of the most proficient killers nature could possibly make...

[@MegaMark0000]

cool. How do they come up with those names anyway? Pod of whales, murder of crows, pack of wolves etc...

[@roboticartist2793]

​@MegaMark0000 they go for whatever feels right

[@Stefmovie]

@@ottovonbismarck7646 Nah, I'd win

[@momsberettas9576]

I think it should be called an apocalypse. XD

[@TheGBZard]

I imagine even after megatheropods go bye bye at the beginning of the holocene their presense would have sent echos throughout human culture forever, sparking stories of the giant feathered dragons which once terrorized the land

[@duitk]

I wonder if the humans would have eventually developed technology or agriculture faster because of the pressure put on by the therapods. Or would the therapods survive until later cultures arrive with firearms? I just dont think humans would not eventually wipe out the therapods, once more ranged weapons, or better traps arrive it may be over for the dinos.

[@stevepalpatine2828]

There's no evidence adult Tyrannosaurs had feathers. No all dinosaurs were feathered. Tyrannosaurs aren't dromaeosaurs.

[@BassFish111]

Tyrannosaurus probably wasn’t feathered as an adult

[@SuperBetaBuxbros.]

@@BassFish111yup

[@SuperBetaBuxbros.]

@@BassFish111dromeossurs

[@Liethen]

Imagine some conquistador, a frenchman, or some cowboy arriving in the great plains to find packs of two ton feathered dragons chowing down on buffalo.

[@ksoundkaiju9256]

“Yeah…I think we should go back home…”

[@adambrennan558]

"Roll out the long guns!"​@@ksoundkaiju9256

[@doragonzx]

"It seems My Destiny Manifested Elsewhere"

[@blairdurward4324]

What’s Spanish for “F this I’m out!”?

[@emilianorios4761]

@@blairdurward4324 La chingada con esta mierda is what you would say roughly

[@riohudson9612]

I absolutely love the idea of Tyrannosaurs evolving into fluffy dragons to rule the ice age. It really harkens back to their earliest ancestor, Yutyrannus, being arctic tyrants in of themselves. It's honestly fascinating how it's become more common knowledge that not only did dinosaurs survive in snow, but on many occasions thrived in it. Some of the earliest dinosaurs, even the earliest archosaurs, were already specialized for cold before they started taking over the world and it came full circle since with Nanuqsaurus and in this alternate timeline colossal woolly-rexes of death!

[@rileyernst9086]

Highland tyrants.

[@MadlyMesozoic]

Great video. Thanks for the shoutout!

[@TheVividen]

I'm glad you liked it!

[@fearthepiggaming2998]

This is wholesome glad to see two of my favorite creators showing eachother some love

[@8bitutopia1954]

This is most likely your best video yet. And thats not an easy bar to climb over. The amount of research and detail here is nuts. You gave both sides very fair arguments, whether it would be elephants vs theropods or early humans vs theropods. I’d say I wanna live in a world like this diverged Pleistocene but if I was actually a human born back then and saw these dragons, I’d be scared shitless. And if they do somehow survive into the Holocene, I imagine they’ll evolve to be smaller, but still probably larger than bison and bears. Imagine Middle Ages North America with herds of bison and gangs of middle-range evolved Tyrannosaurus. Speculative ecology is such a fascination and fun subject to read and or watch. Thank you for providing this kind of content to all of us!!

[@TheVividen]

Thank you so much for your kind words! I researched this one for months to try to get it just right and I'm glad that it was worth it.

[@wildbill9490]

Fascinating. This makes me wonder: what if the K-T extinction had been a little less severe, and some of the smaller dinosaurs managed to survive? How might they evolve during the Cenozoic and how might that affect the evolution of mammals and other surviving animals?

[@TheVividen]

That would be really interesting to explore!

[@jointcerulean3350]

Also bipedal crocodiles as well since a group made it to the Cretaceous

[@dctPL]

Some of the smaller Dino's did survive... We call them birds today.

[@wildbill9490]

@@dctPL I mean smaller species of non-avian dinosaurs

[@dctPL]

@@wildbill9490 Well... Maybe they did and evolved into some species of "birds" we know today. After all, many non-avian dinos had feathers.I doubt that all modern day species of birds were the subject of DNA analysis.

[@Magnaraptor1836]

Tyrannosaurus packs shall be called a Dynasty; Referring to it's definition, A gathering of kings.

[@emersonworst4801]

Dang, that's good

[@gsprojects8474]

That's genuinely a good idea

[@alexandersviridov2937]

Ancalagon caught be off guard to the point that I spat my coffee out - what a legend.

[@TheVividen]

The host of the Valar likely spat out their mead as well!

[@TimothyLau-l8x]

The amount of research/ theorising this man has done just to make my childish brain giggle about T-Rex vs Mammoth… Anyways love the video, keep going man.

[@CB-eo6xo]

Honestly glad this felt very evened out without too much bias between either the Theropods and the Mammals. This honestly feels like the mammals really can in fact stay in the game and adapt pretty well towards the new pressure in spite of the Theropods obviously dominating the Apex predator niches from the get go which than forced some of them to evolve to cope with the conditions that aren't as easy to thrive in compared to their native Mesozoic timeline.

[@adamtruong1759]

It's lines like "pack a firepower of 40 lions into a single animal, and you have Sue!" that truly puts into perspective how large these predators were for me. Also, I was worried for a moment that the therapod team would've needed Nanuqsaurus to carry them. However, this does show how adaptable these animals were.

[@Mateusz-sq9ox]

Great video:) In my opinion "dominion" or "dynasty" for T. rex group seems a better names. "Nightmare" could be great name for a group of Utahraptors, tho.

[@TheVividen]

Thank you for your feedback! Both of those names are awesome.

[@DinoboyLegosandMOCs]

I vote Dominion. It just sounds very cool, just saying Dominion of T-Rexs sounds right.

[@GODEYE270115]

Imagining a gang of giganotosaurus ambushing a paleoloxodon brings out my inner kid

[@TheVividen]

Mine too haha

[@tomatogenesis]

There _needs_ to be a game on this! This was so good to watch and each part was just so well-filled with its own flavor, of which I could never have had enough of. I especially loved that adapted Tyrannosaurus at the Pleistocene part. Please do keep making videos as good as this one was! 'Cause I'll be all down for it!

[@loowick4074]

The thing with elephants is that they are quite sensitive to external Predators they arent used to dealing with. And usually go extinct relatively quickly when threatened. Their slow reproduction means they usually lose any evolutionary arms race and often do not have the numbers ro replenish casualties fast enough

[@GRIGGINS1]

There is evidence of Humans actually arriving in North America 100,000 years ago. I did not say Homo Sapian Sapiens . I am saying Humans as in the other types. And Mammoths and Mastodons kept chugging right along.

[@Devin_Stromgren]

Slow reproduction of large mammals is the biggest problem for the survival of any of the mid or large sized therapods during the Cenozoic. Especially since the theropods themselves would be reproducing relatively quickly by comparison.

[@jessicaczyzewski4198]

​@@GRIGGINS1Annoys me when they try to make humans out to be more dangerous than they actually were like you said he even in the 1850s a group of hunters still be demolished by a single bear because their weapons could not pierce with regards to a bear

[@GRIGGINS1]

@@jessicaczyzewski4198 Yep. Even the Tribes that hunt African Bush Elephants don't do it all that often and don't go after the very large Bull Elephants. Because Elephants are not only problem solving smart they tend to not be alone.

[@beastmaster0934]

@@Devin_Stromgren Yeah, once the large herbivorous mammals are dead, so are the large theropods.

[@7-sBone-Pit]

Oh man I love this, well worth the 26 a month XD

[@TheVividen]

Always happy to provide content for my favorite Snax glazer

[@iratezombiemann]

Fantastic video. Probably your best yet and that was already a high bar.

[@TheVividen]

Thank you! I'm glad you enjoyed it. I think this is the video I'm the most proud of, so I hope it goes well!

[@GEK0dev]

This video was fantastic, I honestly loved the parts with Tyrannosaurus fighting the prehistoric elephantoidea, Mammutidae and just elephants in general. Honestly I would love an updated tyrannosaur PSA from you as you seem to be the most reliable channel on tyrannosaurus, Actually considering speculative weights for tyrannosaurus instead of only giving that to other large theropods, But more or less on the bite, How quick it could crush, Most likely not like a trash compacter but an actual jaw. And this video was a great example of theropods in the Cenozoic in general.

[@TheVividen]

Thank you very much!

[@GEK0dev]

@@TheVividen No problem my friend

[@CloroxThePotatoPriest]

I'm suddenly finding all these quality paleontology and speculative biology channels and these the funnest stuff ever!

[@Cassave78]

Oh my Gosh this was so epic! Looks like the theropods have triumphed over the cenozoic once again! It's pretty incredible how adaptable the theropods are despite all the challenges. Definently an h^2/10 video

[@CB-eo6xo]

I wouldn't say they outright triumphed, more like they are able to thrive and survive well without overshadowing the mammals too much. Especially that the Probosidians are one of the few mammals being able to directly hold their ground and even adapt in an arms race against the theropods.

[@koutaXkaede]

Acrocanthosaurus has been one of my favorite dinosaurs ever since i was little kid, so happy see it getting some love

[@justjoshua5759]

Also the T rex vs mastodon took me back to prehistoric park when Matilda tried to take on martha. Prehistoric park actually could make a great video idea in terms of how it could work with present day ecology and conservation today.

[@cjacobs851]

Apparently the collective term for tyrannosaurs is a terror. A terror of tyrannosaurs. I’d say a nightmare of T-Rex is still up for grabs

[@Username-y2v]

Knowing that woolly mammoths on average weighed less than the average African elephant, and a maximum of almost 8 tons, they would be a great and delicious replacement for the Triceratops and other T Rex prey.

[@Devin_Stromgren]

Right until the rexes ran out of food due to the fact that the mammoths couldn't make new mammoths fast enough to avoid extinction. 2 year pregnancies and all.

[@AschaVovina]

This was beautiful, and props for the shout-out to Madly Mesozoic. :)

[@gambitaku6179]

This was one of the most entertaining and informative vids yet. This totally needs to be a series if possible 😊

[@TheVividen]

Thank you! The first episode (about Africa) is already out!

[@gambitaku6179]

​@@TheVividen Excellent man Thanks so much. Have a blessed day 🙌

[@diegomelo3219]

It’s been a long time since I enjoyed a video this much. The level of detail and measured explanations put into each part was spot on, not too complex but also not boringly simple. 10/10 from me

[@codypass1709]

The way you said that we would be scavengers to the Megatheropods, and they will force us to be farmers are extremely inventive. I really love this speculation, especially the part with the possibility of most of the Ice Age's Megafauna survival into the modern world. Sure we were not exactly the main reason of their extinction, but we were a nail in their coffin. With the great dragons taking the wheel, and us mortals being able to adapt and live with these titanic titans, we can have at least a better understanding with nature. ❤ Keep up the great work man. ❤

[@perrytran9504]

Even early settled (American) peoples would have a tough time with the megatheropods. They are missing a very key ally in the horse, and based on how things went in our timeline their weapons would not fundamentally change all that much even for millennia. Now, early humans with domesticated smaller theropods though... that opens up a lot of possibilities. The medium sized raptors would be a bit redundant with dogs and the small ones with cats, but the larger ones just maaaybe could be selectively bred to fill a similar role to horses. Probably never as common due to their carnivorous diet, but even using them to drive chariots (if we never get to the point we can ride them) would provide a big increase in mobility for warfare or hunting.

[@codypass1709]

@@perrytran9504 How right you are Perry, you make a very valid point about how we would use these critters to our advantage. Imagine a Native American riding on a Utahraptor instead of a horse, due to their similar height and mass, that would be my choice of a steed. But of course a T.rex would be my prized mount, the Mammoth Hunter himself.

[@SukunaKibutsuji]

I like to believe that smilodon and Utaraptors would be competitors

[@S0L1nv1ctus]

Early humans domesticating theropods= dinoriders

[@daniellewillis2767]

I love imagining a giant fluffy chick-like floofball that suddenly opens its mouth and reveals that it's the cutest death sentence EVER! This image just popped into my head when you mentioned therapids getting fluffier...

[@thenerdbeast7375]

The official name for a group of T.rex is a Terror, a Terror of Tyrannosaurs.

[@Aburg76]

2:21 Ah shit, he's real, everyone head for the hills

[@miguelsoto8150]

imagine that you are part of a hunt group and just manage to take down a wolly mammoth, and when you and your friends are preparing the animal, sudenlly 5 scally demons(saurophaganax) almost the size of the mammoth you just take down appears from the woods and start springting towards you, thats horrifing.

[@TheVividen]

Playing mammoth hunt on hard mode

[@JurassicReptile]

I enjoyed the video but I feel like the theropods from allosaurus’ size to smaller got ignored at the end. I would’ve liked if each one got at least a brief explanation of how they would do.

[@TheVividen]

That's a good point. I will work hard to improve the next episode!

[@loowick4074]

Yeah like stuff like cerato would be aces. Not too big to harm large elephants and rhinos while still occupying a macropredatory niche. They won't wipe us out, and we probably won't wipe them out because reptiles kinda breed more, especially if they live in Africa where their food source won't run out. Seems like it will integrate nicely into modern Africa or ice age Africa.

[@JurassicReptile]

@@loowick4074Cerato would have a pretty good time. Bigger than a polar bear and designed for the forests.

[@tyrannotherium7873]

I mean, theropod dinosaurs would be dominant in the Ice Age, but they would be extinct, because the climate was much much colder, and the only theropods. I could probably see that would adapt to the ice age would be Dromaeosaurus and troodontids

[@robinsonray6766]

Yutyrannud & nanuqsaurus were tyranosaurids that thrived in ice.

[@tyrannotherium7873]

@@robinsonray6766 but back, then it was still warmer

[@Mateusz-sq9ox]

@@tyrannotherium7873 dinosaurs weren't cold-blooded reptiles mate, most of them (if not all) were endothermic.

[@robinsonray6766]

@@tyrannotherium7873 it was warmer in general, but these tyranosaurids lived in habitats similar to modern day England which gets freezing in winter. It's a fallacy to think every habitat was warm during the age of dinosaurs. The poles were still cold, not as cold as today's poles, but definitely colder than most other habitats today

[@tyrannotherium7873]

@@Mateusz-sq9ox no shit dinosaurs warm blooded however, the Cretaceous period of Alaska was much warmer back then it wasn’t an Ice Age

[@PrehistoricMagazine]

Another great thought provoking video. I’d say if trex did live in that time period it would be time to employ heavy plumage. Mike

[@josephroberts5243]

A group of megatheropods is officially a ‘nightmare’ now

[@Intrusion498]

The scariest thing about deinonychus isn't that young ones can fly NOT GONNA MENTION SMALL DEINONS CAN CLIMB TREES but the worst thing is that they would likely see us as a prey option oh and they would literally eat you alive oh an I also wanna say on the whole tyrannosaurid or smth like that group thing possibly footprints of multiple tyrannosaurids ot smth it may have been a drought and they had no other choice but to team up

[@loowick4074]

Nope, friendship ended with dog, now deinonychus is man's best friend

[@Benglavosaurus]

​@@loowick4074​​ top 10 largest North American megatheropods 1. Tyrannosaurus rex- 11.5 tonnes 2. Mcraeensies- 8.8 tonnes 3. Saurophaganax- 8.5 tonnes 4. Alamotyrannus- 6 tonnes 5. Acrocanthosaurus- 5.7 tonnes 6. Torvosaurus- 5.2 tonnes 7. Suciasaurus- 5 tonnes 8. Siats meekerorum- 4.7 tonnes 9. Allosaurus- 4.6 tonnes 10. Epanterias- 4.2 tonnes

[@dariodramac]

Having dromeasaurs as pets wouldnt be that bad​@@loowick4074

[@megamente7849]

​​@@loowick4074 "Friendship ended with horse now Maia is my best friend"

[@tristanwilliams4180]

i love to see a Fully Grown Tyrannosaurus Rex Hunt a Woolly Mammoth

[@marclavecc3381]

What a spectacular video!

[@TheVividen]

Thank you!

[@LordSpinus]

Suggestion, if the three main theropods (T.Rex G.Carolinii. S.Aegyptiacus) lived in the cenozoic of africa [Just an idea]

[@tamaltarudey8912]

A tyranny of Tyrannosaurs

[@TheVividen]

Oooh that's a nice one

[@Skyypixelgamer]

I think the elephant situation is handled very well in the spec evo/biology tales of kaimere handles the elephant situation well.

[@ash_art6648]

i love the rex sisters ideas sm I hope they make the rex scary again not malicious and out right evil but for example chancing down cars like how orcas take down boats for fun and playing tug of war with people they catch it would be interesting if they gave the rexs different ways of attacking the smaller is faster and chases prey to the bigger brawler one

[@khaiasaurus2595]

I think a quake of tyrannosaurs sounds the best. I can imagine the sound of a megatheropod group influencing the vernacular used

[@justinw-s1694]

I feel like South America is just gonna be GG for the mammals down there. Gotta deal with the Giga and Carno. Without any really colossal big hitters with a few rare exceptions. Australia would be a very interesting setting however...

[@PowerBalancetheKitsune]

Group of Rex: A Nobility Group of Utah: A Coalition Group of Torvo: A Dominion Group of Allo: A Pride Personally, I'd rather see what would happen if dinosaurs were around today. Also, imagine if mankind tamed Utahraptor instead of wolves in America

[@lincolnross9000]

According to Google, a group of Tyrannosaurus Rex’s is called a “Terror.”

[@noahadams7784]

I love the ending of this video, megatheropods and humans mutually benefiting each other in order to survive, although I feel like it would’ve started differently Early humans in North America seemed to mostly hunt medium to large game such as mammoths. Since the larger and largest of the theropods used these as their main food source I would imagine instead of directly competing with 10+ ton hairy lizards that make the very earth quake in their presence, early humans might’ve decided to hunt the things they didn’t predate on. Furthermore, if the megatheropods could outrun humans for the most part, it would make sense that they would distance themselves from the medium sized carnivores like allosaurus and smaller tyrannosaurs. As for the larger tyrannosaurs like T Rex, I think that instead of competing with them or fearing them, I think that early humans might see the mightiest of the tyrants as gods. Enormous thunderous beasts that lurk in the forests, preying on all that moves and wiping out entire villages by themselves. Their folklore would tell tales of the forest gods, immense hairy dragons that rattle the very heavens with every step, and their booming calls rumbling through the hills, flattening entire mountains in their wake

[@justjoshua5759]

Pretty crazy to imagine how these animals were this adaptable as you get the impression that even mid size aggro predators like ceratosaurus were simply too large and had reproductive cycles too slow in the cold. But it’s pretty damn impressive especially considering the mass extinction element humans present of which other animals simply wouldn’t be able to exist with. Yeah I know they didn’t make it past the Holocene but still very impressive compared to the cenzoic counterparts. Another excellent and epic series edition vividen👏🏾👏🏾 Btw that lion story with the elephants is crazy. Like those African bull kalahari super lions.

[@edwardpate6128]

I've always had a soft spot for Allosaurus. I think pound for pound one of the fiercest predators ever. a

[@elishaberry611]

This was well done sir. The stories and speculative documentaries that could be made from this thought experiment are most exciting to think about.

[@markusbelden4569]

Scotty the T-Rex: HEYO MAMMALS, I'M BACK!!!! Smilodons: OH SHIT!!!!!!!! Arctodus: Hey your the same size as Me WTF?!!

[@fictionvstheuniverse5418]

a nightmare of tyranosaurs, i love it

[@iforgorlol69420]

26:34 i really hope you do this topic some day in the future as a sort of sequel to this video. It sounds interesting and also really cool at the same time.

[@ztk1138]

Could the north American ice age megafana survives in a modern north America?

[@godhimself478]

Yes and no, yes in climate/ weather tue main problem is us kinda living there.

[@loowick4074]

America still has alot of wild area especially Canada and many parts of US where alot of undeveloped land still exists. That's enough space for mammoths. If elephants can live in India, mammoths should thrive in modern north america.

[@houstonguy1984]

Great video, but one possible thing the video left out… if humans were able to domesticate certain less-aggressive wolves into dogs, could it be possible that they would’ve tried to domesticate certain theropods?

[@TheVividen]

That's a super cool idea!

[@James-od4cz]

Bravo, a truly captivating watch.

[@tyrannotherium7873]

I don’t ever recall American mastodons living in the Miocene. I thought they live in the Pleistocene.

[@myleswelnetz6700]

19:40 Or Goji Center’s Tyrannosaurus rex vs. Palaeoloxodon namadicus video, one of my personal favorite videos on that channel.

[@ezradanger]

Megatherapods are always the answer regardless of what the question is

[@Thomas_Name]

I loved the ending. Reminds me of all the old fantasy scenarios in fiction where early humans interacted with dinosaurs.

[@rileyernst9086]

I think the mammoth problem is far from a problem. Elephants being able to effectively defend themselves means that they can maintain a viable population with the occasional individual dying, but not threatening population numbers. I believe that it means that the two groups, therapods and elephants might coexist more effectively, than say the more basal rhino like creatures, which maybe eaten faster than they can reproduce.

[@MarcoPolo-vb1sw]

Megafauna would not have evolved if theropods were around. Raptors would have kept mammal size in check.

[@DunedinDino99]

For those claiming oxygen levels are a problem: Dinosaurs had the same breathing system as birds and crocodiles, which breathe more efficiently than mammals. Additionally, the extant blue whale breathes air and is the largest animal ever.

[@robinsonray6766]

Good points but blue whales are likely not the largest animals ever. There's an ichthyosaur and a ancient whales species that were as large as blue whales, and another ichthyosaur species which was larger than a blue whales and the fossil we have was still growing

[@DunedinDino99]

@@robinsonray6766 Those ichthyosaurs lived during the Triassic when oxygen levels were even lower than Today.

[@robinsonray6766]

@@DunedinDino99 yes good point

[@robinsonray6766]

@qbgrindddd the key word is likely. It's absurd to claim something as the biggest ever, when we only have a fraction of the fossil record and in the last 10 years alone we've discovered 3 separate species that could possibly eclipse blue whales in size.

[@robinsonray6766]

@qbgrindddd likely is the key word. We only know a fraction of the fossil record yet in the last 10 years alone we've discovered 3 separate species that may have eclipsed blue whales in size.

[@spideyfanw1748]

All this speculative ecology gave me an idea. How would dinosaurs compare/compete with modern day dinosaurs aka Birds? Specifically Dromeosaurids vs Terror Birds and modern raptors like Hawks and Eagles? Edit: Also Ratites like Ostriches, Emus and Cassowaries.

[@robinsonray6766]

Dromeosaurids filled a different niche than birds of prey, during the age if dinosaurs other birds filled the niche of modern birds of prey. Dromeosaurids and terror birds filled a similar niche. Dromeosaurids and terror birds both had many biomechanical advantages including airsacs and hollow bones. The issue with birds is that they have a posture issue ever since they lost their bony tail thus making them front heavy which limits them. A 200lbs terror birds will smash its beak into prey while a 200lbs dromeosaurid would jump on top of prey, grasp with its 4 limbs and bite. Essentially, they could take out bigger stronger prey. Predators need some athleticism in order to catch prey. Birds poor posture limits their size, you need a column stance ti be large. The biggest terror bird was nowhere near as large and powerful as a Utah raptor

[@spideyfanw1748]

@@robinsonray6766 The biggest of Terror Birds stood taller than an human. Couldn’t the biggest just kick the shit out of Utahraptor like Ostriches and Cassowaries do to people and other animals today? Also Modern birds of prey could see smaller dromeosaurids as food since they’re small enough to be picked up and I believe that they would also compete with bigger dromeosaurids for the same prey items. Or would they all just coexist with no one eating the other?

[@robinsonray6766]

@@spideyfanw1748 you're 100% right about birds of prey being able to eat smaller dromeosaurids and sometimes competing for the same food, but it goes both ways. Regardless they filled different niches. Dromeosaurids lived alongside birds, some of which were almost identical to birds of prey today. Enantiornithes were more diverse than today's birds during the cretaceous but filled identical niches. Dromeosaurids dealt with them how theid deal with today's neornithine. Utah raptor, when leaning upright, would be about 10ft tall. Theropods are typically depicted vertically but they could certainly and likely usually leaned in an upward posture when fighting to make themselves seem larger and in this position their claws are in perfect position. Utah raptor was far too massive and powerful for terror birds. Ostriches are about 10ft tall as well. They wouldn't stand a chance

[@Lonely_artist102]

I don't know why, but every time I see this thumb i just see a yutiranus using a top hat

[@atriox7221]

I’d like to imagine that if this full set of pre KT predators listed were reintroduced to somewhere around the Texas region early into the Pleistocene, and given 1.5 to 2 million years to adapt and disperse. Several species could end up entirely in South America, while others fully inhabit the northern regions of North America (as far as glaciers allow them to reach at least). And other species go all directions and split into new branches of species. I’d imagine that you could see a very small number of the larger species per region of the Americas, those most predisposed to feathery coverings at younger ages adapting to have full coats as adults and taking over the north, the most dominant for each niche keeping control of southern NA and Central America, many new species branching out as various species expand further south through the equatorial climates and even have to separately evolve plumages once reaching Patagonia. So by the arrival of humans, the amount of Saurian biodiversity would be unimaginable, let alone imagining what these many new selective pressures would force native species into adapting for, perhaps a population of mammoths grow bigger, more intelligent, and live in notably larger groups, becoming uncanny in closeness to humans in regards to trends towards early societal evolution. Perhaps some of the Saurian species also become notably more intelligent over this large timeframe, maybe forming proper social packs, if they already had such things, perhaps they get more sophisticated with smarter members and the beginnings of language, tool use and culture like seen in tribal bird species such as numerous corvidae species. Regardless, by the time humans reach the continent, I seriously doubt they could spread nearly as fast, perhaps not even making it past the modern day western half of usa. sticking to Canada and extending to Greenland so far north that any additional predators barely differ from the irl polar bear problem they had. Even if humanity does expand all the way through the Americas, I assume the level of advancement would be astronomically reduces as a culture is formed from scavenging and hiding away for most of the day, revering the giants. I would be curious weather this makes European colonisation easier or futile, perhaps it is sped up in terms of native retaliation, but slowed down in terms of wildlife problems enough that it results in merely a slightly slowed down expansion. At the same time I don’t think the settlers would be migrating beyond intended lands as quickly, resulting in far more coastal development east of the Appalachian mountains, through Central America, west of the Andes, and along the southeast coast of Brazil down to Patagonia. Colonies of the Americas may be far less Iberian dominated as only more valuable coastlines better suited to establishing a decent population without major issues are invested in, at least until the European technology improves enough that the wildlife becomes a non issue, allowing major inland expansions to occur in the 16th to 18th centuries, in turn seeing a very different set of nations prevalent in the expansions, perhaps even giving the Prussians and later Germans time to get a colony or two. Regardless of if and how this affects the colonial age in terms of land acquisitions and later developments, it would certainly change the worlds understanding of nature, especially is any megafauna of the mammoth/elephant variety still remains which possesses even greater intelligence than any elephants of our reality thanks to the Saurian selective pressures. Even more so any dinosaur species that could have became notably intelligent, assuming their social developments follow the same path as corvids. This definitely is one of the more interesting concepts for speculative evolution both of species and societies.

[@mewmew1511]

Incredible video, major props

[@koboldking2991]

I can't believe you actually got Thomas Holtz to commentate on this! Amazing video!

[@gsprojects8474]

14:15 Basically, nothing that Sukuna hadn't seen in the Heian area

[@The_Darke_Lorde]

I think a group of T Rex should be called a Kingdom, because they're Tyrant Lizard Kings. Also, I believe their younger forms should be named after noble titles. Hatchlings could be Barons, then Counts, Dukes, Lords, and then becoming Kings/Queens.

[@germanscience7246]

I wonder if people arriving in north america would utilize similar tactics against the theropods that they used against mammoths like spike pits or just strsight up dropping a large rock on their back

[@BabyGodzilla-lb5vw]

I wold love to see a follow up to this where it's the Dinosaurs from the end of this videe being put up to every historical era of Humans from the ones at the end of this one, to modern day ones of the 20th century

[@DreadEnder]

I’m not really that interested in the whole, “what if this and that organism interacted.” But these are very entertaining.

[@Dinoman-rt1uv]

Rule number 1 like before its even out.

[@TheVividen]

You deserve a gold medal, but a heart's the best I can do

[@Dinoman-rt1uv]

​Can you please do Asia or Euraisa next because I really want to see how the biggest landmamals perform.​@@TheVividen

[@TheVividen]

​@@Dinoman-rt1uvthat's the plan! South America is also on the list.

[@Shafi756]

Next: if megatheropods could survive in modern world

[@ksoundkaiju9256]

*RPG sounds*

[@juritudi57yearsago59]

Yes if humans don’t wage war on them, easy w for modern humans

[@ambrosianonyt]

humans would probably kill most of them if no laws or regulations were set in place. the large and slowly growing animals will probably be first to go because humans love to stroke their egos by killing the biggest, baddest animals around. i could see megatheropod parts becoming black market staples in lesser developed countries. they would still be in our shadow within developed nations that have conservation laws, as unless an animal is threatened with extinction regulated hunts are still allowed to happen. though if the late 1800s up into the 1960s count as modern then theyd be royally screwed, humans killed anything and everything for sport back then. if they appeared during that time period then theyd probably be dead by now

[@brycesmith9878]

What an excellent video! This cements your position as my favorite prehistoric KZbinr! Anyway, a thought about packing hunting for the megatheropods. Is it still considered pack hunting if its a mated pair of acros or rexes? Pack hunting in my head is like a wolf pack or lion pride, not two big megatheropods and maybe some of their young.

[@TheVividen]

Personally I wouldn't consider a mated pair as a pack, but I think any more than two would count. The tyrannosaurs we've discovered in groups seem to have a wide range of ages, so family groups may have stuck together well into subadulthood.

[@brycesmith9878]

@@TheVividen well, that makes life much, much suckier for mastodons, mammoths, and whatever else a megatheropod pair would decide to make a meal out of

[@TheVividen]

​@@brycesmith9878That's for sure!

[@spiderlime]

when i think about the possibilities of theropod evolution after the period known as the extinction aftermath, it makes some sense, at least to me, that they would evolve into somethink like terror birds, possibly much larger, with serrated beaks. they may still have tails, but much shorter ones.

[@brycesmith9878]

God I love these videos from you! Bye the way, is there any information on how eggs would be affected by the ice age?

[@ApostleoftheDarkness]

I think you should do a sequel; How the Megatheropods would survive to the Modern Day

[@Username-y2v]

Could I do the Asia chapter? I want to see the theropods against the great P.Namandicus

[@atToebiscuit]

I think P. namadicus would fair well. Big adults are more than 3 times the weight of Tarbosaurus and Zhuchengtyrannus, the largest theropods in Cretaceous Asia.

[@denistyrant]

@@atToebiscuitA single individual maybe but a pack would be a nightmare, not to mention Zhung already coexisted with dinosaurs that were around the size or larger than P. Namadicus

[@palmbeach4825]

Dear Vividen, I'm glad I finally found an episode on your channel introducing anatomically modern humans to the dinosaur dynasty. I am still interested in seeing how would humans fare against these reptilian threats throughout human history. As in how would different cultures across time would deal with dinosaurs. A few examples would be: Ancient Indians using sauropods instead of elephants in warfare, dinos in the Colosseum, Knights slaying Trex, Pirates ☠️ facing Mosasaurs, Cowboys 🤠 riding dinosaurs and finally the ultimate showdown with WW2 🪖 soldiers landing in dino infested battlefield. This would be an interesting match-up because there is a linear progression of weapons from roman ballista to machine guns, from Lancers to cannons. And don't forget the atomic bomb. Would the President order a tactical airstrike against these prehistoric invaders? I'm really looking forward to an episode like this. 🙏🤞 Thank you Edit: Humans are interesting bunch given how we use other animals to our advantage like dogs 🐕 as pets, horses 🐎 for riding and poultry🐓for meat. How would dinosaurs survive this level of exploitation? Would mosasaurs face extinction like whales 🐋? Would Triceratops suffer from poaching?

[@CharlieBrown-wj3hl]

This is a such a brilliant and well researched video, I was absolutely hooked. Somebody needs to write a novel based on that alternative theropod-infested and their encounters with early humans

[@TheVividen]

Thank you! Said novel is a series in progress....

[@dariodramac]

​@@TheVividenTAKE MY MONEY!

[@ferociousrazordino3581]

Do you think the clovis would eventually try to work together with theropods and make them pets like humans did with wolves?

[@TheVividen]

That would be awesome! I didn't even think about it. They'd probably have the best luck with the likely pack hunters since they could adapt the preexisting gregarious tendencies to their advantage.

[@jointcerulean3350]

Something like a smaller tyrannosaurid

[@shahinarahaque2071]

For Asia, continuing on the Theropods in Cenozoic continents before humans, I think the contenders should be the following: Our mini monsters are gonna be Sinocalliopteryx, Citipati, Adasaurus, and Tochisaurus. Moving up to the small-mid tier killers, we got my boy Achillobator(or Uberraptor), Gallimimus, Qianzhousaurus, Shidaisaurus, Indosaurus, Monolophosaurus, and of course, Yutyrannus. For our Monsterous Megatheropods, We are gonna use Sinraptor as it hunted large Sauropods, Rajasaurus as it was proficient at choking and bleeding large game, Chilantaisaurus as it's pretty much a more brawling Sinraptor, Therizinosaurus, Deinocherius, and Tarbosaurus as it killed Sauropods.

[@godzillakingofthemonsters5812]

Next suggestion: what theropods would survive into the Holocene, could be from any continent or this one as a jumping off point.

[@knowncoralconsumer]

[@worldbigfootcentral3933]

Unlike the theropods usual prey, Mammoths were FAR smarter, and look at the tactics of musk ox and American bison for how they handle pack attacks

[@antediluvian2380]

27:10 I really enjoyed this video, but I think you were a little more than optimistic in the end..... Unless someone decided to domesticate the theropods, which would also be a probability.

[@waffletop1018]

according to google, a group of rexes is called a terror

[@RubyCarrots3232]

You know, Yutyrannus/Nanuqsaurus being frigid climate predators already would have it made here.

[@BobbyB1928]

I doubt it. Surviving the cold of the Americas during the Ice Age would have been a problem that would require evolving a thick coat of feathers which it's questionable whether Tyranasaurs even had potentially making the Saurian T Rex outdated. Not to mention rats eating their egs and the human threat. By this point once humans crossed the Berring Strait it was only a matter of time. They were resiliant enough to survive the mini extinction 10,000 or so years ago and would have certainly been able to eventually overpower the Tyranasaurs. They not only had sophiaticated weapons like the atl atl but also had fire and advanced tactics that they could use to their advantage. Other megafauna didn't last long once humans arrive and I don't expect Tyranasaurs or other larger therapods to do any better.

[@evanloukas3900]

Along with the humans scavaging off of the dino's kills I also feel they would go after the eggs of the dinos. That paired with the rats would cause a huge blow.

[@RosalinaDeAnda]

Amazing, you did amazing witn this video. Dinosaurs in the Cenezoic is a hot topic of debate that people should look at more. You did an amazing job giving all the information and evidence in a very good manner. I personally think the Theropod Dinosaurs can survive in the Cenezoic but there will be challenges like: Proboscideans, humans, and smaller creatures. Amazing job I can't wait to we what other Paleontology videos you will make.

[@ronniehopper2726]

I want to know if humans could survive the cretaceous period

[@Ratchetcomand]

Didn't Titanis also lived in NA in the Pleistocene too? You forgot them.

[@atToebiscuit]

What can Titanis do that Utahraptor already can?