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RE: Combined answer Archaeopteryx running...




-----Original Message-----
From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
James R. Cunningham
Sent: Friday, March 08, 2002 12:10 PM
To: Williams, Tim; dinosaur@usc.edu
Subject: Re: Combined answer Archaeopteryx running...


Williams, Tim wrote:

>  However, at a certain point (probably early in the Pygostylia) it
> became advantageous to dedicate the manus and carpus to flight, so both
were
> absorbed into the wing.

Then why did pterosaurs retain the manus all the way to the K/T?<<
Not all of them did. According to Benett's SVP talk in Mexico City,
Nyctosaurs (with that weird crest) lacks a manus, and he was referring to
all Nyctosaurus. Also if you look at the manus in pterosaurs, the Cretaceous
pterosaurs mani are smaller than the Jurassic. Crazy as I am, I don't think
pterosaurs went into tress and was a ground based animal.

>  By contrast, the cumbersome flight
> abilities of _Archaeopteryx_ (compared to pygostylians) precluded these
> birds from forging certain novel niches - e.g. anything that involved
aerial
> hovering, marathon flights, or stationary take-offs.

And the lack of a hand precluded the later pygostylians from some grasping
maneuvers.  One life style is not inherently 'better' than the other.<<
This whole talk on pygostylians and long tailed 'birds' will in the next few
months be all the more relevant. We've already heard about the specimen
Norell mentioned (and not described because he can't, someone else is)
should be published in a few months (or so I was told). Hang on to your
hats, it's going to get interesting!

Jim

Tracy L. Ford
P. O. Box 1171
Poway Ca  92074