I think the argument has been mostly settled in favor of the "lukewarm-blooded" theory, but it'd still be interesting to see if anyone has any dissenting opinions.
it's pretty well established that all theropods were warmblooded imo
I guess there's still a case to be made for some non-theropods being lukewarm-blooded but I wouldn't bother at this point, I mean ceratopsians were living through winter in cool-temperate polar climates and if they weren't warmblooded than no dinosaurs were
Yeah but there are plenty of big archosaurs that are ectothermic. Not that any of them approach the size of a ceratopsian, but the proof of concept is there. Look at some alligators in the U.S., they make it through occasionally-freezing winters.
If they can be ectothermic, I feel like something 3x their size could still get by on being mesothermic.
Look at some alligators in the U.S., they make it through occasionally-freezing winters.
Yeah but late cretaceous arctic winters got colder than winters in the range of alligators. There's no gators in Montana today and a polar cretaceous winter would have been similarly cold. The same arctic site that I'm thinking of re:ceratopsians specifically turned up zero remains of reptiles or amphibians despite them having sieved and sorted all microfossils
a polar cretaceous winter would have been similarly cold
For real? I don't know much about cretacious climates but I thought the era was generally warmer than the quaternary. Like no-ice-at-the-poles warm. Happy to be wrong about this, that was just my impression.
no permanent ice at the poles, correct; but sea ice in winter wasn't out of the question IMO. It was a lot warmer but that still meant a cool-temperate continental climate like, say, continental eastern europe or the northern Rockies
Hmm... Ok. Idk. The thing that put me in the lukewarm-blood camp was a paper I read about dinosaur growth rates (specifically therapods and sauropods, I think?). The argument was they grew in a way that was too seasonally-dependant to be warm-blooded, but too quickly to be truly cold-blooded. Or something along those lines.
in the final calculation the important thing is that dinosaurs are neat
They lived an active lifestyle even during the night and in polar regions and developed insulating feathers all of which strongly suggests warm-bloodedness.
I thought this debate ended decades ago.
It ended as far as nobody is really questioning it that greatly. Even when new evidence shows up its basically in line with the idea they had warm blood.
I was under the impression that warm-bloddedness in theropods was a relatively late development. That older ornithischian groups showed evidence of growth patterns closer to crocodilians than birds; evidence of lukewarm-bloodedness.
But I never meant to suggest that our noble warm-blooded bird friends were cold, cold reptilians.
Well, let's go down the line: Differentiated teeth ✅ Carnivourous ✅ Synapsids ✅ Probably assholes ✅ Super cute ✅
Sound like cats to me!
no they just used water innit, it was a long time ago, blood probably didn't evolve yet you know?
Maybe they had like, the live-beta version of blood. Like the Model-T of blood.
see what gets me is, why has nobody just asked the dinosaurs?
They're poor communicators. Grew up in emotionally-stunted homes. Hard to ask them anything.
