[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Outcast Pterosaurs (was Arms into wings)
Larry Febo said:
>I`m not sure how that can be determined from the limited fossil evidence.
>I`m assuming that the skin as well as any integumentary covering would in
>fact be quite similar. Even the orthodox phylogeny has pterosaurs as a full
Limited? I'd say the fossil evidence is good enough. And we do agree that
pterosaurs are archosaurs.
>Well , again,...Padian states "The detail of many resemblances between
>pterosaurs and modern birds is uncanny,..." And here he is spreaking of
>all those items you mentioned (shoulder, ankle and pes).(see Padian`s "The
>Origin of Pterosaurs")
This wouldn't surprise me, as pterosaurs and birds are both archosaurs and
have *gross* anatomical similarities. The demands of flight are so rigid
that there are simply a limited number of ways in which vertebrates can
modify their bodies to achieve powered flight. Pterosaurs did it one way,
birds a second, and bats a third. Since the latter two are obviously more
closely related to one another than either is to bats, it is to be expected
that they share more similarities is terms of their volant adaptations,
which they achieved *independently*.
In short, pterosaur and bird similarites remind me of the numerous
convergences between marsupial and placental mammals. Are they descended at
all from another?
>Well, fossil evidence in this particular area may be scant, but I think that
>eventually, Pterosaurs are going to get the recognition they deserve,
>...that is , not just flying lizards,(sitting on the sidelines 8^) but
>something much closer to dinosaurs in the evolutionary shceme of things.
We certainly never considered pterosaurs (my favorite fossils, BTW) as
"flying lizards." Taking the etymology literally is really stretching it.
Who nowadays believes that dinosaurs are "terrible lizards?" As the 1996
SVP meeting in New York showed (wish I was there), pterosaurs certainly
merit a lot of attention. Otherwise Padian, Unwin, and company wouldn't
have devoted a session just for them.
They *are* close to dinosaurs, anyway. They're the sister group, unless you
believe the alternative "descended-from-prolacertilians" theory.
An article I read about insects mentioned that the appearance of the
pterosaurs must have influenced the evolution of insects, as they now had
to face competition and aerial predation for the first time. That's
cetainly an accomplishment for the pterosaurs.
Raymond Thaddeus C. Ancog
Mines and Geosciences Bureau