is a preconceived notion on what an early bird would look like. But when
one is found in the Late Triassic it is considered to be a composite because
it doesn?t fit that preconceived notion. I?ve talked to Sanker and the
person who excavated _Protavis_. I believe them that it is just
one genus in the block. I bet even if a totally intact, articulated specimen,
it will still be thought of as a composite animal.
Interested parties are directed to view a two page spread of the remains
on pp. 44-45 in :
Steele, Bill, "Ruffled Feathers," _Discover_, May 1992.
Compare with Chatterjee's illustrations (sans photos) in _The Rise of
Decide for yourselves whether the reconstructions are accurate and the
claims of the avian nature of the specimen justified. At the risk
of stating the obvious, I think that the bones would be much more useful
if there were more of them and they were in better condition (as in Tracy's
opposite is true for _Rahonavis_. It is a long tailed bird that
is older than Archaeopteryx.
to 65-70 million years before present, this is not correct. It combines
features of early birds and dromeosaurs, but its late appearance suggests
that it is a throwback rather than an early bird itself. But I know
that you knew that.
the physical difficulties of getting dromaeosaurs up a tree, this is less
problematical in the recently described smaller forms, such as _Bambiraptor_
and the eagle-sized _Sinornithosaurus_. Even smaller species may
well have existed, and not been preserved, particularly if their habitat
was a tropical forest, and immature dromaeosaurs would surely have been
"small enough" to have jumped around in the trees if they had wanted to,
long arms, retroverted pubes, cat-like claws and all. And the pivotal
theropod ancestor of the birds need not have been a dromaeosaur per se,
but rather the most recent common ancestor of both dromaeosaurs and early
birds (such as _Archaeopteryx_).
the question of arboreal dromaeosaurs, perhaps we'll have to wait until
a preserved dromaeosaur nest is found in a fossilized tree to nail this
one down! (All right, George, I know you can't speak of this until
the paper comes out (joke))!