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> Lets see where this takes us:
> In the early Jurassic, a branch of the theropods evolves feathers and flight,
> producing birds. One branch of early birds GIVES UP flight, producing
> Archaeopterix and evolving into more highly developed flightless maniraptoran
> dinosaurs. These guys survive the Jurassic-Cretaceous extinctions and move
> into the space vacated by the allosaurs. In the mid-Cretaceous, a branch of
> the maniraptors gives up long arms and becomes gigantic. Thus, in this
> scenario you could say Tyrannosaurus evolves from birds!
> Mike Bonham email@example.com Jade Simulations International
One fact seems to be regularly forgotten in these Archie discussions
whenever they occur - he/she couldn't have 'flown' in the trus sense. No
keel! That rather large, cartilagenous hunk of white stuff that all the
white meat is attached to on your Christmas turkey (no sarcasm intended -
sorry in that came across the wrong way!). In the fossils of
Archaeopteryx I've seen, I've never seen traces of the keel, which is an
anchor for the large muscles required to power wing-driven flight. Now,
this doesn't answer to the possibility that Archie was a glider - just
hold those suckers out there, and let the currents carry you out there.
But this would reflect on them being able to get to areas where they
would be able to take advantage of these currents, i.e. climbing trees.
Oh, what a tangled web we weave...
Earth Sciences Dept.
Memorial University of Newfoundland