Could Giant Mammals Survive the Cretaceous Period?

What if giant mammals coexisted with dinosaurs? How would mammoths, ground sloths, saber-tooth cats, and more Cenozoic giants fare in the Late Cretaceous? Prehistoric megafauna in the Cretaceous were extraordinarily dangerous. This video analyzes ten megamammals and their chances of surviving in the Hell Creek formation of North America. We look at Smilodon, Elasmotherium, Megatherium, Livyatan, Perucetus, Arctodus simus, Mammuthus columbi, Gigantopithecus, Daeodon, and Paraceratherium. We analyze their ability to find food, adjust to the environment, deal with competition, and avoid the terrifying Cretaceous predators, and rank each of them on a scale of 1 to 10 in terms of survivability. They’ll confront Mesozoic natives like Tyrannosaurus rex, Triceratops, Torosaurus, Ankylosaurus, dromaeosaurs, and other ancient creatures. This speculative ecology analysis is the third episode in the series examining if Cenozoic giant mammals could survive the Mesozoic. How would they respond to a Cretaceous environment dominated by huge ceratopsians, hadrosaurs, and megatheropods? Could they survive the apex predator, Tyrannosaurus?

00:00: Tusks vs Teeth
00:52: What Was The Hell Creek Paleoenvironment Like?
02:15: Smilodon populator
04:23: Elasmotherium caucasicum
06:51: Megatherium americanum
08:11: Livyatan melvillei
09:10: Perucetus colossus
09:46: Arctodus simus
11:45: Mammuthus columbi
16:08: Gigantopithecus blacki
17:11: Daeodon shoshonensis
18:20: Paraceratherium asiaticum
19:48: Could Giant Mammals Survive Hell Creek?

Soundtrack by Paleowolf! Thumbnail art by Arturo Garcia, Lizat, London Museum of Natural History, and cisiopurple.

[TheVividen]

SOURCES
I outsourced the editing for this one since I’ve been so busy this summer, and some crediting/captioning errors crept in a result. At 6:16 the art was actually by Allotyrannosaurus, and a Tyrannosaurus was erroneously labeled Dakotaraptor at one point. If you see your art vaguely or incorrectly credited, please let me know so I can update this comment.
Edit: AtakDraws was incorrectly labeled as kyrumlack as well.

[goldfishmentality]

Livyatan is the perfect example of: "yea, I could get used to this."

[nikolagnjatovic]

so basically the t rex is the bouncer stopping a lot of animals from living comfortably if placed in that time period.

[Saurophaganax]

Mammals: We have Smilodon, Mammoth, Megatherium, etc.

Dinosaurs: We have T. Rex

[rl]

“Mmm, monkey.”
-Tyrannosaurus when Gigantopithecus are introduced into Hell Creek

[alexius]

We need Mega Ichthyosaurs put in cenosoic Ocean with Megalodon, Livyatan and Otodus Chubutensis.
Ichthyotitan vs Megalodon would be insane

[greenturret]

Ice Age Sloths are known to rizz single Mother Tyrannosaurus, so I’d increase their survival score by a point or two

[SonLucasX]

Always the T-rex is the biggest obstacle. In other places in the world during the late Cretaceous there were not so many mega theropods comparable to T-Rex in size, certainly Cenozoic animals would have had more chances.

[adamtruong]

I feel that one thing to mention about the Wooly Rhino is that it's eye sight was probably not very good, while having a pretty good sense of smell. So a determined Tyrannosaurus Rex could easily exploit this weakness, especially at night (unless the rhino got whiff of the stench the megatheropod must've had).

[beastmaster]

So while all the land critters are fighting for their lives against a metric fuckton of threats,

Livyatan and Perucetus are living the good life, feeding on whatever the hell they want, and not having to worry about attacks from anything larger than them.

[gonzalitorg]

This edition is top notch, great video Vividen.

[rl]

I loved this series! I know how long it took to make these videos, and I understand why you’d choose not to continue this series, but other installments with more creatures would be great! Maybe to simplify things, it could be focusing on a single type of mammal surviving in Hell Creek or some other Mesozoic habitat. Creatures like the American Lion, Paleoloxodon, and Megistotherium would be great picks.

[SafavidAfsharid]

Should have included simbakubwa and straight tusk elephants.

[TheRoachmellow]

I love that Daeodon’s and T-Rex’s dynamic is literally Jogo and Sukuna.

“Stand proud, you were strong”

[TheGBZard]

Congrats on finally finishing the trilogy! These kinds of videos are not only unique but also fun to watch, and I wish you the best of luck on your future videos.

[fabianvidrio]

Love your content vividen, keep up the good work.

[josh-themighty]

It was so cool to finally get to see the finale as I ate my breakfast this morning!! Once again I can't thank you enough for making this series on my request :)

I'm glad and agreed with Smilodon scraping out a living along the Arctodus and Daeodon as you said regarding the latter two generalists are the most successful

The Columbian mammoth and Paraceratherium unfortunately did/would suffer from casualties to predation as you said although I do think a hard neck whack from a Paraceratherium might help it although I can imagine them loosing a tail in a hunt at the minimum sadly. And the mammoths well strength in numbers so maybe bull males would form coalitions more frequently to the risk of Tyrannosaurus? But overall I was happy with the Columbian mammoth's chances they oddly seem to do better in the late Cretaceous then they did the Jurassic.

As for Megatherium, I believe they have armour underneath their skin but that obviously wouldn't stop a T.rex bite so sadly I think they'd either succumb to predation or maybe they'd shrink dramatically to not be noticeable??

The whales domination of the western interior seaway surprises me because I thought Tylosaurus or Mosasaurus would be at least dangers to individuals but maybe the danger posed by them would be too great to consider viable meals.

[LucasRodrigues-ghdm]

s there a possibility that you could make a video about the Cretaceous predators of South America in the Cenozoic period, or the North American predators that migrated south from your previous video? If not that's alright

[viniciuspaiva]

I also love how MadlyMesozoic presented paths some of these megafauna would go through already!
Well, with modern animals, but still…

[PhyoThantKoKo-uw]

This is the ultimate clash of the Titans battle between mammalian megafauna and mezazoic might.