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Re: Neoteny & Avian Evolution




On Fri, 14 Nov 1997, Casey wrote:

> What if birds evolved as a result of neoteny from a very
> early (as of yet undiscovered) dromaeosaur relative. 
> 
> When Varanus komodoensis young are born they quickly scurry up trees to
> avoid being eaten by adult animals and other animals as well.  Perhaps the
> same was true of early dromaeosaurs.  They may have been born with feathers
> (or feather-like structures) for thermoregulation (or what have you) and
> quickly scurried up the trees.  Eventually several may have had a genetic
> mutation that caused them to reach sexual maturity prior to adulthood and
> began to produce offspring with the same predilection for mating before 
> full maturity.  At the same time their arboreal lifestyle also played a
> role in selecting those animals who were capable of scurrying about in the
> limbs of the trees and larger feathers (eventually leading to flight
> feathers) would have been a very advantageous adaptation (as well as the
> grasping digits of the manus as seen in young hoatzins who may lead a
> "somewhat similar" lifestyle.)  This would progress until eventually you
> had something similar to Archaeopteryx.
> 
> Casey T.
> TUCKERCJ@MUohio.edu
> Miami University
> Oxford, Ohio

Another scenario:

Okay, what if it wasn't a dromaeosaurid but a compsognathid from which
birds developed.  It seems just as likely that dromaeosaurids would have
been derived from early birds (like a neoteonous _Archaeopteryx_).

Jack