Re: Thecodont pelage (and scutes)

[TomHopp@aol.com]

Ken Kinman wrote:
<<Of course, if the development of "thecodont pelage" began in the Permian, 
my proposed "predator evasion" (tail pelage) strategy may have been just a 
Permian phenomenon, exapted for brooding and even internal thermoregulation 
by Early Triassic times.   The more I think about it, the more I like this 
"tail-first" hypothesis.>>

I just replied to the "Archosaur Origins" thread with some insights you might 
want to consider. Teeth are structures that arrise from follicles, too. Looks 
like we may have room for one more acronym-based debate: TCF.
   Does it mean "tailfeathers-came-first," or does it mean 
"teeth-came-first"? Though we would be debating homologous structures IMHO, 
we would be at diametrically opposite ends of the organism. As I said on the 
other thread, there is real molecular evidence of homology between teeth and 
feathers. To me, integumentary structures seem able to crop up ANYWHERE on an 
organism, via simple regulatory gene mutations (even simple point-mutations. 
Considering the shark, with its organism-wide coverage of teeth, ANY 
distribution of dermal appendages seems possible from the Devonian onward. In 
fact, the polychete annelids have some pointy dermal appendages too -- 
Precambrian, anyone?

Thomas P. Hopp
Author of DINOSAUR WARS, a science fiction novel published by iUniverse
Now Humans are the Endangered Species!  http://members.aol.com/dinosaurwars