As the article states, some dinosaurs were definitely warm blooded, some were definitely cold blooded, but where in the tree the transition happened is very much unknown.
This article doesn't make the connection, but it's an interesting hypothesis to assume that all cold blooded creatures that were big couldn't maintain their body temperature after a drop in temperature from a comet impact, but that creatures that were small already were better in coping with fluctuations because of their smaller size.
The thought the latest theory was the entire earth was engulfed in flames from the impact and killed almost everything except stuff underground / underwater
No, in fact, the whole point is discussion of the evolution of warm-bloodedness among dinosaurs. Are you just guessing what the content might be based on the headline and reacting based on that guess?
>> "What we can see in the fossil record is a number of bird-like theropods with hair-like structures and simple downy feathers. Being mostly small creatures [they must have generated their own body heat] and evolved hairs and feathers to help retain the body heat they generated," says Willis.
Is it possible that feathers evolved first, for some other reason, particularly mating displays, and, once evolved, opened the way to endothermy?
[Disclaimer: I'm completely not a biologist at all, so this is probably a stupid question, but I seriously wonder nonetheless]
Edit: Funny typo in the article. The phylogenetic tree of dinosaurs says: "Theropods (meating-eating dinosaurs)".
"descended from" is kind of a common misconception about evolution. Birds and Dinosaurs have common ancestors. Earlier researchers thought they were closely related to reptiles, but more recent research has shown they have a lot more in common with birds.
It's still somewhat of a mystery as to why dinosaurs went extincted. A very large asteroid did hit the Earth at the end of the Cretaceous. But there was a lot of other thing happening on Earth at that time. Pangea was breaking up and major waterways/oceans were opening up at that time, so there was likely major climate changes occurring, incearse Volcanism, etc..
I suspect it's because birds fly high and in cold wind, they had to evolve, or they would crash down like a frozen cube (at the very least stiff muscles and wings are not beneficial to flight). Quite the pressure from survival of the fittest.
