“Dinosaurs are responsible for the end of the reign of the synapsids” Literally wat. The reign of the synapsids ended with the end-Permian extinction event, the single most devastating extinction event we know of-it makes the end-Cretaceous extinction event that killed the non-avian dinosaurs look like peanuts. There were a few successful lineages of synapsids after that (one of which was mammals, which evolved around the same time as the dinosaurs), but by and large, there was exceptionally little interaction between non-mammalian synapsids and dinosaurs, as practically all non-mammalian synapsids had gone extinct before dinosaurs even arrived on the scene. What was mostly outcompeting the surviving synapsids in the early-to-mid Triassic were the pseudosuchians, early crocodile relatives. It wasn’t till the mid-to-late Triassic that dinosauromorphs began to outcompete the pseudosuchians, and by that point the mammals and their immediate ancestors had already doubled down on the small nocturnal omnivore niche that they would mostly continue to occupy for the rest of the Mesozoic, with relatively sparse experimentation outside of that niche.
Yes its better to say the Great Dying wiped out a great many of the Stem Mammals allowing Dinosaurs to radiate into the new niches. But its believed Dino's had two adaptations that allowed them to survive the Great Dying and its after math better than the Stem Mammals. Dino's were mesothermic, meaning they could go from being cold to relatively warm blooded as conditions warranted. This meant they needed less food on whole compared to true warm blooded animals, but could also be more active than true cold blooded animals. Which is why true mammals got small, they doubled down on warm bloodedness and had to adapt a form that could survive the post Great Dying world. The other reason Dino's flourished post Great Dying, is because of the way they breathed. All Dino's Avian and non-Avian had one way respiratory systems. This may have allowed them to better endure high heat in their environment and lower oxygen.
+Christopher Mbolinani Uh, hold the phone, Boyo. Your a mammal yourself. Anyway, egg laying has it's disadvantages, as your unborn young are more vulnerable. What if someone else takes your eggs, what get swallowed in a storm or an avalanche, what if they get lost, or what if they go raw and are infertile.
Its now believed many of the Stem Mammals in the late Permian and proto/true mammals in the age of the Dinosaurs had either some or all hair. Like how non-Avian Dino's are thought of today with most having some or all feathers/feather like structures. Its was the discovery of fossilized poop from both sets of animals that changed everything as new discoveries showed fir and feathers. Not as left over food bits, but as in sheading like mammals and birds today do.
yes, but even the largest mesozoic mammals were restricted to near chick-sized, baby dinosaurs; only be to killed themselves by the baby dinosaurs larger relatives
Isn't it weird how what we used to think our ancestor did to kill the dinosaurs (Being smarter, faster, eating their eggs) is how the dinosaurs killed off our ancestors.
Fascinating that mammals were being outcompeted and found more success as smaller versions that were mostly nocturnal. Great adaptations for survival in a dino ruled world. Pure luck they survived though when dinos died off. Much of evolution is luck though.
There is no luck. The small mammals were smarter than small dinos. and thats why they out competed and became the ruler. however small dinos evolved to become birds of today which is a lot smaller than most mammals. The pattern keeps repeating itself. If anything happens to the big mammals of today... the birds will most likely rule the earth and we might see supersmart birds in the future. There where probably not enough food for the big mammals to survive and thats why they died.
+Leon Birds already existed for tens of millions of years before the mass extinction, they didn't evolve right after it and they were not outcompteted by mammals, are you forgetting which animals were pushed into nocturnal modes of life? once they occupied different niches there was no competition anymore. On the other hand it is true that Birds couldn't fill the niches opened after the mass extinction.
Also during and after the years of the Great Dying. The planet was probably at its hottest, with great million year Siberian eruptions (aka Siberian Trapes) being the catalyst. This also meant that during those same years the amount of oxygen in the air was probably lowest since the Cambrian. Avian and non-avian dinosaurs are thought to be mesothermic, meaning they could control their body temp more than any other animals in history, meaning they could relatively speaking handle extreme heat and extreme cold. The other part is that avian and non-avian dinosaurs have a one way respiratory system (unique to them). Which made them able to survive and thrive in lower oxygen levels than any other land animal. So by the time conditions became favorable for stem mammals to bounce back, the Dinosaurs were already large and in charge.
