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Re: The birds vs. the pterosaurs
At 07:07 PM 05/02/01 +0000, Matthew Bonnan wrote:
"Perhaps they went extinct later,long after the mass extinction occured,
because they were aced out by the birds. Perhaps the birds made the old
flying archosaurs obsolete.
While it may be true, in the end, that birds out-competed pterosaurs, we
should remember that they existed side-by-side for tens of millions of
years. Also, we have no idea (other than guesswork) of the extent to which
they overlapped ecologically. Birds and bats coexist today, and some have
suggested that this may be primarily because bats are, generally, nocturnal
whereas relatively few birds are. Both birds and pterosaurs were quite
diverse in the Mesozoic, probably more than we realize because of the
scarcity of their fossils. Rather than birds eliminating pterosaurs across
the board, it seems more likely that, in some situations, birds prevailed
while in others they did not. It is, perhaps, instructive that the latest
known pterosaurs were much larger than any known bird; possibly something
about their internal architecture a them better adapted to large size, so
that the role of the giant flyer became uniquely their own.
>Maybe birds had different reproductive strategies than pterosaurs which,
by chance, allowed them to survive the K/T event.
Is it actually known whether any pterosaurs even made it as far as the
K/T? Am I not correct that at least one line, the rhamphorhynchoids, did
not even survive the Jurassic, and that the group's diversity diminished
towards the end of the Cretaceous?
"Perhaps, like the corvids of today, the pterosaurs didn't change much
physically over the years, but instead "chose evolutionarily" to "work on
their brains", ie, they adapted mainly by getting smarter. ) By the mid
cretaceous, I believe the pterosaurs were the smartest thing on the
planet. You can correct me if I'm mistaken."
There is absolutely no way to determine this, of course, although I have
never heard that their brains were particularly large (though I assume they
have large optic lobes, and would certainly needed pretty good higher brain
functions to control the mechanics of flight. That certainly isn't the
same as intelligence, though.
Ronald I. Orenstein Phone: (905) 820-7886
International Wildlife Coalition Fax/Modem: (905) 569-0116
1825 Shady Creek Court
Mississauga, Ontario, Canada L5L 3W2 mailto:firstname.lastname@example.org