Re: Feathering in coelurosaurs

["Matthew Bonnan" <mbonnan@hotmail.com>]

Just to throw my hat in the ring here:

Does anyone know of a large reptile that is brightly colored or even 
colorful?  As far as I know, crocs, large snakes (Anacondas, boids, etc.), 
Galapagos turtles, and the like are all relatively dull colored animals, 
even though all of these reptiles see in color (please correct me if I'm 
wrong).  On the avian side of things, ostriches, emus, and other large 
ground birds are relatively drab as well.  I don't pretend to know why this 
is, but it's interesting.  What is it about getting larger in both these 
groups that seems to dull their colors?

If we use a phylogenetic bracket hypothesis, then, we might be able to say 
this, if birds and crocodilians represent the living outgroups to dinosaurs: 
(A) Since both crocs and birds have color vision, that would make it a 
"primitive" or symplesiomorphic trait for dinosaurs and all ornithodirans; 
(B) Based on this hypothesis, dinosaurs would have primitively had color 
vision; (C) This might imply colorful patterns for display or deception, but 
of course none of this testable.  Dinosaurs may have been drab animals when 
they became larger, if the trend we observe in living avians and 
crocodilians holds true for all archosaurs.  Are there any large archosaurs 
that are very colorful?

I suppose in the end, if the current relationships between dinosaurs and 
birds and crocs hold, we can be reasonably sure that dinosaurs were 
primitively color-seeing animals.  What colors they were, or if the large 
dinos were color-impaired, is at the moment beyond the reach of a direct 
scientific inquiry.  While we're all waiting for cloning to bring back 
dinosaurs (and Matt Wedel will agree with me that sauropods should be the 
first to be cloned), maybe an area of investigation would be to study skin 
coloration in large and small archosaurs and see if there is some 
integumentary reason for the "color change" with size.

Matt Bonnan
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com