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Re: Testing for arboreality (was RE: On science (was Re: a bunch of other stuff))

could you jump the gun on such a test by emphasizing the study of
flightless and mostly flightless arborial birds (animals that shares
some large percentage of qualities such as bipedalism, etc, with your
ultimate comparison group of theropods)?

Does it count if you're concentrating your data collection with types
that seem to share more qualities with each other, or does it really
require the study of the set of all arborial animals?  It seems unlikely
that there would be any useful correlation with say, Archeopteryx and a
two-toed sloth.

-Betty Cunningham

"Thomas R. Holtz, Jr." wrote:
> And that is indeed how it works: it is possible to construct tests which
> eliminate possibilites.  The statement "theropod X was arboreal" is
> impossible to prove; however, we can get much further by restating the
> hypothesis "theropod X could not be arboreal" and testing this statement.
> However, how to test?  Therein lies the difficulty.  Below I reveal a
> potential research program to do this study.  It will be long; it will
> involve a lot of measurements; I suspect that it might make a good Masters
> Thesis for those in search of one.
> The heart of the problem is that the questions about theropod arboreality
> (or scansoriality) have been extremely poorly thought out.  First of all, we
> have to recognize that there are different methods of getting into and
> clambering around trees.  Off the top of my head, I can think of some of the
> following:
> *Clambering up the sides a la squirrels, cats, etc.: claws are used, but no
> grasping with the hands & feet as such;
> *Shimmying up the sides a la sifakas and some other primates: long arms and
> hands are used to grasp the trunk;
> *Creeping up and down the trunk a la woodpeckers and other tree climbing
> birds;
> *Walking along the tops of branches;
> *Brachiating underneath the branches;
> to name a few.
> So, the first step will be the categorization of different modes of movement
> in trees.  Among the groups to examine would be birds, primates and other
> archontans, various carnivorans, some rodents, edentates, various
> marsupials, and a lotta lizards.
> The second step is the search for some osteological correlates with these
> behaviors.  Here's where the fun begins...
Flying Goat Graphics
(Society of Vertebrate Paleontology member)