Re: Evidence that colors my opinion...

[chris brochu <cbrochu@fieldmuseum.org>]

>>>
>Just yesterday I watched a program on the Travel Channel that showed
>color-changing young caimans on the Patanal...so why is it so difficult to
>imagine in their archosaurian kin?<<
>
>Really?!  I've never heard of color-changing crocodilians.  (I had heard of
>those color-changing fish, but forgot about them).  By what mechanism do the
>caimans change color?  Chromatophores?  Or is it a gradual process of color
>change as they get older?  I know all sorts of organisms do that.
>


No living crocodylian can change color.  Color patterns may change as the
animal grows, but instant color changes like in chamaeleons do not occur
within the group.

I suspect what was seen on TV was changes in shading or such - I've spent
plenty of time watching living crocs (including caimans of several
species), and have never seen color change.


chris


------------------------
Christopher A. Brochu
Department of Geology
Field Museum
1400 S. Lake Shore Drive
Chicago, IL 60605

phone 312-665-7633
fax 312-665-7641
electronic cbrochu@fmppr.fmnh.org