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Re: feather stuff



>On Sat, 10 Feb 1996, Morgan Family wrote:
>
>> >>  ...and, of course, another reason why, in my mind, it's likely that they
>> >>all had feathers is the question of insulation on the smaller dinos.

<snip>


>That's a good point--does anybody know exactly how
>cold the Mesozoic poles DID get?
>

Analyses from the Dinosaur Cove excavations indicate average temps of -4
degrees Centigrade. While results from different tests apparently vary,
they do not get too much warmer than this. During the early Cretaceous
Dinosaur Cove was at around 80 degree South latitude. So the answer "bloody
cold" should suffice.

What does this tell us about feathered dinosaurs? Seeing as Dinosaur Cove
is dominated by small hypsilophodontids and, taking the implied assumption
that feathers are the best way for dinosaurs to keep warm, then we can
clearly see that feathers must have been a synapomorphy of saurischian and
ornithischian dinosaurs. Which, by extension, clearly indicates that forms
such as Triceratops, Stegosaurus and Iguanodon must have been feathered. I
think that a strong note of caution needs to be placed here; be vary
careful about over interpreting the data. Of course, I could throw in the
fact that fossil feathers have been found in the contemporaneous and
closely located Koonwarra beds and, as yet, no birds are known from either
Koonwarra or Dinosaur Cove.

Cheers, Paul

pwillis@ozemail.com.au