Why Didn't the Dinosaurs Take Over Again?

Any attempt to really answer this question comes down to a simple WE DO NOT KNOW.
Worse - we have no idea why it did not happen.
Nor do we have ANY idea as to why the smaller dinos (which were many species of) did not survive the catastrophe while comparable size mammals did, not mentioning crocs, lizards and the rest of the crew.
So - let's be honest - there is NO answer to this question, at least not yet.

So there are a whole bunch of dino fossils in the same layer as the asteroid impact material?

What a lot of these shows continue to ignore is what happened to the small bipedal dinosaurs?

I absolutely adore this channel. Thank you for making educational and highly entertaining content. I am truly obsessed!!!!

Your show is super cool

How did big animals like elephants and rhinos come from?

TLDW:






That's just the way it is.






Otherwise known as shoulder shrugs

🫀⚰️🫀

nice intro

Fascinating!

This got me thinking... What if snakes reevolve legs? Or even fins?

It actually crashed in the Gulf of Mexico.ah gastornise the terror bird they’re carnivores

that's gonna be funny

My son Flynn would like to know “How did dinosaurs form anyway?”… He also loves TimTim. I know your long form videos cover this… but do you have a shorter primer on the topic, or is the Late Triassic video coming soon?! Love the channel.

please do a video about turtles and their relatives

Nice and detailed, but I'm missing the simplest part of it:
To continue after the extinction event the dinosaurs needed to reproduce, and that might have presented an absolute roadblock in any of several ways:

Due to absence of skeletal remains above the iridium layer we assume no dinosaurs survived past the impact, but dinosaurs reproduced through eggs, and with eggs protected in nests, eggs might have survived the impact, at least for some species; likely some even did.
However, some dinosaurs cared for their young like birds, so without surviving adults it meant the end of the line in those cases.
Dinosaurs also didn't brood like birds, but left their eggs to the environment; maybe sometimes helped by vegetation providing insulation or heat through rotting.
That strategy would have collapsed with the extreme atmospheric conditions following the impact and extremely few young would have come out.
Moreover, it's quite possible that the sex ratio depended on the incubation temperature - whereby any offspring surviving the previously listed issue might have been of one sex only, which won't take you far as a species...

Today we see turtles struggling with that last problem, due to global warming, and that's nothing compared to the climate upheaval back then.

So, I guess the problem was that all the adults died, leaving any hatching young without support; and that the few young that did hatch were hopelessly few and largely incapable of reproducing.
Even if a few had managed to clear those hurdles where were the ecosystems previously supporting the recent overlords of the previous world?
The previous underlings were likely better adapted to live on scraps.

The other groups of animals, those that did survive might have fared better on all of those parameters, with more initial survivors and reproduction and feeding strategies that were better under the extreme circumstances.

they kinda did tho... not only did they diversify as modern birds but they basically came back as theropods again as terror birds. pretty neat

Could there be a dinosaur hollow earth ecosystem, what species of dinosaur evolve form will be like and how would they get pass their extinction.Hollow earth ecosystem of dinosaurs is very interesting to me to this very day today

Tim-Tim reminds me of Gleep from the Herculoids.
Dating myself again...

Mammals rule, dinosaurs drool.

They did. Theres still more birds than mammals.

Yes I'm completely new..thanks to Lindsey Nikole...legit your voice just makes me wanna listen...I found out about Lindsey cuz Minute man....bout I think I'm gonna just absorbe...gotta learn about our past ti understand our present and future..

We like learning the information, so deep dives into the phylogenetic data and the evolution of our interpretation of the data would be interesting. It would be interesting to show ten different representations of the same creature.. and why we have changed our opinion on how they looked.

Another example would be how we determined that fossils were different creatures.

Long Live The Empire!!

Basically cats saved us from the dinosaurs 🦖🦕

Because birds are unironically d tier dinosaurs

You forgot the giant land croc in South America. 😂😂

This is such a great question and a great video. I've had a question and maybe it's stupid: Dinosaurs were around about 2.5 times longer than it's been since they've been gone, yes? So mammals have had only about 2/5ths the time that dinosaurs had to fill out all the niches that the dinosaurs once occupied. The question I have is what does that mean? Were dinosaurs somehow "more advanced" because of that than mammals are now in any measurable way? What is the significance of having that much more time to compete and evolve? Is there any? Or maybe the effect of an ever changing environment acts so much more quickly that it nullifies any effect I might be imagining? Or maybe the question doesn't make sense at all?

Actually if you look at the lineage of Dinosaurs who evolved into birds it is an evolution toward high mobility and speed and as a consequence eventually holow bones, air sacs and flight. An eagle is about the same sise as a velosoraptor ( the real one , not the one of Jurassic Parc film) but is vastly superior because it can glide effortlessly on big distances and survey a vast areas in search of preys but this mobility and flight direction of evolution involve limited size .

You try recovering after getting nuked and facing an ice age. Not so easy now is it?

That fallen tree at the start really looks like Hallucogenia. A deliberate pun type thing?

We are all midgets

I would absolutely buy a timtim plushie if you ever opened a merch store, just saying.

That Tim Tim, such a scamp!

Ask this to a goose. I dare you.

I’d argue birds ruled for a long time and even came back just before the ice age for a few mya (like arthropods kept coming back) also meaning there’s 2 mammal rules.

This climate explains Titanomyra, these giant ants look like they belong in the Carboniferous or Permian, but nope here in the Cenozoic.

Why didn’t any other kinds of dinosaurs besides birds survive the asteroid and radiate? Surely there were other small species/kinds/groups/clades/etc. (whatever classification/grouping you want to use) of dinosaur that theoretically could have survived, just like the birds, amphibians, reptiles and mammals did

I love this video, got recommended again, watched it again

I’m jumping through your content out of order, so this doesn’t apply to just this one video: I wanted to say I love your videos and hearing you talk about literally all of this, and I’ve learned a ton that I never knew about the history of life on our world. Also I love the avatars you use in different videos. If I was to request any content, it would be more of anything about underwater life from any time period. Love your work and thanks for the many hours I’ve spent watching, re-watching, and absorbing it all.

P.S. Long Live TimTim!

Great video! Here's a follow up question:

As some non-avian dinosaurs at some point turned into avian-dinosaurs, which then turned into what we know as birds today, how come - after the reset caused by the asteroid - that birds never evolved back into having proper teeth, tails, arms with usable hand-claws, etc.?
It seems like, there could've been a niche for such birds/dinosaurs at some point. However, we only got things like Terror Birds with beaks and no tail or arms with claws, but (so far at least) never got something like a Dromaeosaur again.

I knew what happened to the dinosaurs the first time I hugged a parrot and smelled lizard 🦎. I fifteen in the seventies. Twenty years before science cot up.😅😅😅

I didn't watch the video, but the answer is because they are dead.

Lack of a counterbalancing tail and full length fibular bones, the tail would have allowed birds to shift to femur driven locomotion and grown to full theropod size, and the fibula would have strengthened their legs to allow for the new/old body plan. They could never grow larger than Kelenken as they are too front heavy and essentially trapped in a crouching position.

This us tim tim first apreed

Gastornis as a plant eater... I've never considered it!
For that little detail alone. I subbed. dude, my hats off to you!

Plus the origin story behind Tim Tim was uterly hilarious.

I was so delighted to find out that birds are dinosaurs, and I occasionally go out into my back yard and say to the various birds living there, "BIRDS ARE DINOSAURS! YAY!"