Re: competition between Pterosaurs and birds

[nhi158@aberdeen.ac.uk]

> > 
> 
> Sorry to carp, John, but...
> Rhamphorhynchoidea is (?was) a paraphyletic group.
> Pterodactylus did not belong to it (except in the sense that all
> pterosaurs do)
> 

Sorry about the mistake. Pterodactylus is not in the Rhamphorhynchoidea but in
the Pterodactloidea. The other two species I mentioned are. Wether these are
paraphyletic groups or not is irrelevant. Almost all the supposed insectivorous
Pterosuars were in the Rhamphorhynchoidea, and this remains true.



> There is no solid evidence of insectivory in any pterosaur; this has only
> been surmised. The only definite evidence about diet in Jurassic species
> that I know of is that Rhamphorhynchus was a piscivore.


Agreed. However the morphological evidence that at least some of the smaller
Pterosaurs (particularly Batrachognathus) were insectivores is quite convincing
(see Wellnohofer 1991 The Pterosaurs). If none of the Pterosaurs were
insectivores then the speculation that they were outcompeted by the aerial
insectivorous birds is sterile anyway.


> 
> As for birds not flying in the Jurassic, I think this group has covered
> that thoroughly.

Unfortunately as I have just subscribed to this list I have missed most of the
debate about Archaeopteryx and early flight, although thanks to N. Clark at
Glasgow I have some of the early messages. My personal feeling is that flight
performance in Archaeopteryx is definitely still under debate. Since
Archaeopteryx is pretty late Jurrassic I don't think it is unrealistic to
suggest that large numbers of diverse birds were not using powered flying
until into the Cretaceous.> 
> 
> 
> 
Cheers

John Speakman
J.Speakman@aberdeen.uk.ac

Dept of Zoology
University of Aberdeen
Aberdeen
AB9 2TN
Scotland UK

Tel : + 44 224 272879
Fax : + 44 224 272396