re: dinos and birds

[Stephen Moore <smooreph@yahoo.com>]

     The amazing thing about birds is their ability to
fly(along with insects,and bats now and pterosaurs)
and therefore colonize new environments in the form of
islands. This could possibly have given them a
selective advantage when under heavy environmental
pressures or disasters. If able to colonize islands or
other remote and newly formed environments couldn't
this give them a safe haven from a wipe out on the
main continents? The problem with this theory is that
the pterosaurs went extinct along with the dinosaurs
and many other now extinct Mesozoic creatures. Since
now the consensus is that the pterosaurs were furry,
warm blooded, highly active and robust
animals(contrary to opinions when I was a child of the
fragile pterosaurs, barely able to glide from tree to
tree) why did they not survive like the birds? 
     GSP 2002 speaks of several advantages birds have
over the other flying vertebrates mainly in the that
the primary flight structures of birds, the wings, are
independent of the walking/running appendages, the
legs, unlike bats and probably pterosaurs who have
them joined. Evolution has developed bats and
pterosaurs into excellent flyer's but they would be
hard pressed to evolve further into terrestrial bipeds
or quadrupeds. Birds could theoretically fly to an
island, colonize, fill niches, grow gigantic and
flightless and prosper for a few million but when the
water levels begin to rise, for whatever geological
reason, the bird cannot return to the air and
perishes. It is highly unfortunate that we are unable
to find more island fossils from the Mesozoic because
we would be surely amazed but what oddities we might
find judging by todays islands

=====
Stephen R. Moore
University of Kentucky
3277 Tisdale Dr. 40503
Lexington Kentucky
H 859-223-3880
M 859-492-2738


                
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