[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
<Date: 26 Feb 1999 09:52:57 -0500
From: "Norton, Patrick" <Patrick.Norton@state.me.us>
To: "dinosaur list (comment line)" <email@example.com>
Subject: RE: Rahonavis....Both!
<Actually, if you accept Chatterjee's claims about Protoavis, you'd have
to believe that flying avian forms were around much earlier than
that---since he claims that Protoavis is more a derived "bird" than
Archaeopteryx, even though it's considerably older. >
Not if Archie is considered as having actually lost some of these advanced
features (ie. acrocoracoid process and large sternum), and is on its way to
becoming secondarily flightless at the stage in which it was found
ALSO,...(he added when he realized he didn`t exactly answer the "problem" in
the first post), I do think that the above mentioned flight features are
VERY advanced, (and therefor not likely to have evolved twice). They took
some time developing in prolacertiformes(from early Triassic) as they
progressed toward the Pterosaur-Bird stage(mid-Triassic). When Birds and
Pterosaurs split, the acrocoracoid process was already in place.
That`s my theory,...otherwise, if you follow Chatterjee, who`s trying to
resolve his find with the BAMM point of view, you`re going to have to start
looking for Dromaeosaur-like ancestors in the early Triassic, ...(not
likely). Or ....politely ignore the significance of his find altogether.
more about my point of view at http://www/capital.net/~larryf/index