

Re: Evidence that colors my opinion...

>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.


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