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Re: Flightly PaleoWorld

In a message dated 95-11-21 11:32:27 EST, Thomas_R_HOLTZ@umail.umd.edu (th81)

>...the idea that the common ancestor of dromaeosaurids and birds
>was a small scansorial theropod, some of whom's descendants evolved the
>ability to fly, is not only far from ludicrous, it is better supported
>than the theory that small feathered protobirds lived in vast numbers in the
>Triassic or earlier :-)

Thank you, Tom Holtz. Meanwhile, that's not the impression that was conveyed
by the show. The show did not mention any common ancestral forms for Archy
and dromaeosaurids, for example, nor did they mention small size as a
necessary pre-adaptation for flight. They did mention that Deinonychus occurs
later in the fossil record than Archy, but in a different context. The
overall impression I was left with was that we had these 50-100 kg
Deinonychus-size dinosaurs climbing into trees as the first stage in the
development of flight. Balderdash.

Longisquama is a good example of a small Triassic protobird, although it is
too derived to serve as a theropod/avian ancestor. I can't imagine that it
appeared by special creation in the fossil record of Russia, so there must
have been related/ancestral species, very probably dozens, probably even
hundreds, alive during the Triassic all over Pangaea. Why is this so hard to