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Re: evasive, camouflaged flocking

Betty Cunningham brings up a good point with the giraffe having
"camoflauge."  However, let us keep in mind that color vision is the
primitive vertebrate condition (help from Mickey Rowe on this one?) --
fish, amphibians, reptiles, and birds all see in color to varying
degrees, and many see colors in a wider spectrum than humans.  Most
mammals, in contrast, have poor color vision.  Primates are the odd
exception to this rule.

The dull colorations of mammals may be due in part to the lack of
color vision in these animals.  On the other hand, fish, amphibians,
reptiles, and birds tend to be very colorful animals, in part perhaps
because they can see those colors.

Large dinosaurs may or may not have been colorful, and I don't know
what the current thinking is on this issue.  Large 'gators and turtles
tend to be "uncolorful" I've been led to understand because as they
grow larger, their skin thickens and the pigments become "dulled"
having to pass through many layers of epidermis.  I have no reference
for this, but if someone does I'd be keen to know.

In any case, again we must be careful when we go too far with
mammalian analogs for dinosaurs.  Since birds and 'gators both seen in
color, it appears likely that dinosaurs did as well.  Whether this
means the big dinosaurs were very colorful, I don't know.  Mickey Rowe
gave an excellent talk on color vision in dinosaurs at last month's
regional GSA meeting in Illinois.  Perhaps he'd like to elaborate on
it here?  I would be interested.

Matt Bonnan
Dept. Biological Sciences
Northern Illinois University