Re: Warm-Blooded debate

[Dinogeorge@aol.com]

In a message dated 97-06-25 12:03:34 EDT, MissRaptor@mindless.com (Swift
Claw) writes:

<< Out of the argument whether they were warm-blooded or
 cold-blooded, all that comes from the cold-blooded side is defense!
 Why the warm-blooded evidence COULD be wrong, although they provide no
 evidence of their own.  What kind of closed-minded people could possibly
 belive in such a weak argument as that? >>

The problem is not >whether< dinosaurs were endothermic, but >which<. We may
assume that when the dinosaur-to-bird lineage split away from the crocodilian
lineage, the animals on that lineage were not yet endothermic, because
present-day crocs are ectotherms and it is unlikely that any kind of
full-blown endothermy in the archosaur lineage at that point would have
reversed to give us ectothermic crocs. Somewhere along that lineage, the
dinosaurs began to develop endothermy. We know this because living dinosaurs,
that is, birds, are endothermic. Stretch out the line from the common
ancestor of croc and dinosaur to the common ancestor of modern birds. Where
on that line, and in what stages, does endothermy come in?