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Re: paleontolgist, dinosaur
On Wed, 20 Nov 1996, Stan Friesen wrote:
> From: Jeff Poling <firstname.lastname@example.org>
> > This is the first time I've seen this hypothesis. I doubt it's true.
> > The first known flying bird is mid Jurassic, some 75 million years before
> > the K/T event. Recent fossil finds show that birds were widespread and
> > diverse by the early Cretaceous at the latest ... yet pterosaurs survived
> > right up to the big figurative boom.
> True, they survived, but apparently at *greatly* reduced diversity.
> Only about three families of large "Pteranodon"-like forms are known
> from the entire Late Cretaceous. This is compared to the enormous
> variety of smaller pterodactyloid and rhamphorhyncoid pterosaurs
> known from the Late Jurassic. And I know of only one or two families
> from the Maastrichtian (the one containing Quetzalcoatlus, and perhaps
> the one containing "Titanopteryx", if that is distinct). Indeed I
> only know of a small handful of *genera* in the Maastrichtian.
How diverse would the late Jurassic appear without Solnholfen? How
diverse would the Early Cretaceous appear without Santana? The
Late K. doesn't yet seem to have it's Santana or Solnholfen. And
even so... it seems like the Confuciusornis locality isn't exactly
teeming with pterosaurs, nor is Las Hoyas. If we only had these to go by,
would we also assert low pterosaur diversity in these times? The decline
may be real, but remember, for over a hundred years we went without any
clue of how diverse the early radiation of birds was, and now stuff like
Confuciusornis, Sinornis, the Madagascar bird, the Chinese longfeather
bird, etc. are implying previously unsuspected early bird diversity. Yes,
the fossils are consistent with low pterosaur diversity, but until
recently, they were consistent with low bird diversity as well. The
evidence at this point is negative. Now, maybe we're not finding fossils
because there weren't a lot of pterosaurs. But then, until recently, we
could have said that maybe there weren't any feathered dinosaur fossils
because there weren't any feathered dinosaurs. I do think, however, that
we will findout one way or the other, sooner or later.