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Re: ABSRD BAND on Sinornithosaurus feathers



----- Original Message -----
From: "Steve Brusatte" <dinoland@lycos.com>
To: <dinosaur@usc.edu>
Sent: Wednesday, March 21, 2001 2:35 AM
Subject: Re: ABSRD BAND on Sinornithosaurus feathers


> The sulphur hypothesis seems a little weak to me, but George is right when
he says that the sulphur idea wouldn't be restricted to any type of animal,
while insulation as a hypothesis would basically be restricted to
warm-blooded animals only.  Obviously, birds are warm-blooded, but I would
definitely tend to say that endothermy developed after the feathers (like it
developed after hair in mammals, if I'm not mistaken).

Endothermy developing after insulation? This seems very improbable to me,
because ectotherms would actually suffer if they were insulated --
insulation cuts their means of temperature regulation! I'd say insulation
developed shortly after endothermy in dinosaurs and probably mammals. (Wrong
list here, but what is state of the art on the origin of endothermy in
mammal ancestors?)

> Interesting stuff, although I tend to shy away from the entire evolution
of flight debate.

Not flight here! Feathers! Feathers, wings and flight are probably at least
two, IMHO three, different issues! :-)