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Re: Gliders to Fliers? (Was Re: Ruben Strikes Back)
In a message dated 9/27/99 5:34:34 AM Pacific Daylight Time,
tholtz@geol.umd.edu writes:
> > From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> > Larry Febo
> >
> >
> > Which brings to mind the dilemma...if theropods were developing
bipedality
> > in order to run faster, why would they develope feathers on the arms, or
> > larger arms for that matter. It seems this would tend to slow them down!
And from Tom Holtz:
> ...the origin of Theropoda and the origin of feathers seem (with
> current evidence) to be two separate events: theropods split off from other
> dinosaurs first, and feathers can only be tied with confidence at present
to
> the base of Coelurosauria.
Indeed; and bipedality came even earlier than Theropoda, at the base of the
Dinosauria.
Our dear Mr. Olshevsky notwithstanding, most workers see bird ancestors as
having been bipedal long before any adaptations to flight arose; thus the
origins of bipedality and the origins of flight are two completely different
issues--though the fact that early birds were bipedal before they began to
fly may have a lot to do with the decoupling of the forelimbs and hindlimbs
in birds, relative to bats and pterosaurs.
--Nick P.