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Re: Ornithodira, breathing with long necks
> >As much as I want to believe all dinosaurs were endothermic like mammals,
> >can't convince myself that it is the only explanation without answering
> >these questions.<
> While the evidence does seem to point towards endothermy, I don't think I
> would agree that it would be a mammalian style endothermy. Rather, if
> anything, it would be avian, or primative avian, where their resting
> temperature can drop a good deal.
Don't underestimate birds. Most or all have higher body temperatures than
most or all mammals. "Primitive", hm, I'd rather say the ability to fall
into torpor is a secondary adaptation in e. g. hummingbirds as well as in e.
g. bats and hibernating mammals -- and what are "primitive" birds? Ratites?
Ratites can't do such tricks like torpor.
While I don't know their temperatures, sloths have reduced metabolic
rates, and HP Paul's article suggests that therizinosaurs had similar
energy-saving adaptations. This is also the usual explanation for the low
body temperatures of marsupials (35 °C) and monotremes (30 °C or so).