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Re: Terrestriality is a bias



    Rob said [Subject: Re: Terrestriality is a bias],

"Just a thought, but is it possible, that some troodontids and/or
dromaeosaurids could have been arboreal...you figure that those claws could
have been useful for digging into bark and climbing, not just killing. I
don't think that this would even cause a blunting of these claws. If you
look at modern felines, most have very sharp claws, and cats are known to be
climbers. I know this isn't very easily testable, but I just thought I'd
throw it out here.
Peace,
Rob (Yes, I am new to the list)"

    This brings to mind a paper Paul C. Sereno delivered at Dinofest '98 in
Philadelphia: "COULD BIPEDAL DINOSAURS DRIBBLE A BASKETBALL".  [It was
preceeded, coincidentally/amusingly, by a paper entitled, "...And The
Sauropods Wore SNEAKERS", by Sheila M. Stanford and me!   ;^) ]  In
Serreno's paper, he explained that because dribbling a basketball,
"...requires substantial long-axis rotation of the radius over the shaft of
the iulna to pronate the manus...SNIP...Bipedal dinosaurs, as a consequence,
do not appear capable of dribbling a basketball". (See THE DINOFEST
SYMPOSIUM abstracts publication, 1998, The Academy of Natural Sciences,
Philadelphia, page 54, for the Sereno abstract, and page 57 for the Stanford
& Stanford paper.)

    Now that we are on the question of arboreal 'non-avian' dinosaurs, I
cannot help but wonder whether those bipedal dinosaurs, having a fore-arm
manus orientation capability as described in Sereno's paper, might have been
pretty well adapted to climbing trees, in those cases where, as Rob
suggests, the claws were appropriately shaped.

    I realize that the popular image of the function of claws of certain
Theopods as instruments of prey capture may have put 'blinders' on me,
growing up, toward contemplating other possible adaptations of certain
bipedal dinosaurs' forelimbs.

    And, now (Please don't flame me!), while personally (only slightly)
favoring a trees-down scenario as the (or at least a) major factor in flight
development, I wonder why so many of us seem to seek a simple 'only way'
solution to flight development, sometimes refusing to entertain the
possibility that two or more factors or behaviors might have contributed --
either equally, or differentiality -- toward flight.  To paraphrase Cirero
and add a question mark, 'Couldn't there have been more things happening on
ground and in trees, than have been drempt of in our simplistic scenarios?'

    Have at it, if you will.  I'm out of here!  :)

    Ray Stanford