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Re: Dragons Of The Air
Jonathan Woolf wrote:
> My strictly amateur's opinion is that the drawings, sketches, and
> anatomical data is probably still accurate. So, most likely, are many of
> the genus and species names. I'd guess that classifications are
> probably obsolete, although as far as I know pterosaur taxonomy has
> never undergone any sweeping changes like dinosaur taxonomy has.
> > A specific question is around Rhamphorhynchus phyllurus. It is given as
> > from the Solenhofen slate. I didn't know that Pterdactyles (his
> > spelling) were found at Solenhofen. Have these specimens all been
> > reclassified? My first assumption is that I'm not aware of everything
> > published on the subject.
> Many, many pterosaurs have come from the Solnhofen limestone quarries.
> Many superbly preserved pterosaurs, including a few rivaling the Berlin
> _Archaeopteryx_ in degree of preservation. In fact, the very first
> pterosaur specimen, _Pterodactylus_, was found in the Solnhofen.
Although pterosaur taxonomy hasn't indeed underwent revolutionar
changes, some present research does suggest that at least the
Solnhofen pterosaur material has suffered some 'over-split'
classification (just as many other fossil taxa studied and named the
first half of our century, the nicest example being the South African
therapsids (there have been named more than HUNDRED Dicynodon
species...)). According to Christopher Bennett from the University
of Kansas, many of the named Pterodactylus species do in fact reflect
ontogenetic (growth) stages of a single species; in the fossil
material he even recognizes 'year classes' of pterosaurs, which might
suggest seasonality in sampling of the fossil material. The same
would apply to this other famous Solnhofen pterosaur, the
long-tailed Rhamphorhynchus, of which five named species could be
lumped in one single large species, R. muensteri.
Bennett: Year classes of pterosaurs from the Solnhofen limestone of
Germany. JVP 16(3), 1996.
Bennett: A statistical study of Rhamphorhynchus from the Solnhofen
limestone of Germany. Journal of Paleontology 69, 1995.
> > But that brings up my next question: what is the acknowledged overlap
> > between true feathered species vs membraned species? Is there a long
> > record of overlap with both types coexisting?
> "Feathered species" meaning birds? No pterosaur ever had feathers.
> _Sordes pilosus_ is supposed to have had a hairlike outer covering, but
> I think that's still open to question. Pterosaurs were common pretty
> much throughout the Jurassic and Cretaceous, until they were also wiped
> out by the K-T event. They would have coexisted with birds throughout
> the Cretaceous.
I remember a theory which said that the small "rhamphorynchoid"
pterosaurs dwindled and disappeared during Cretaceous times due to
competition with birds, the only pterosaurs that survived until Late
Cretaceous times were the large pterodactyloids.
This sounds nice but is highly speculative (sample bias can for
example be responsible for this); moreover I have the impression that
'competition based extinction scenarios' are nowadays a bit out of