Re: beating a dead elephant, arctometatarsaly

["John R. Hutchinson" <jrhutch@socrates.berkeley.edu>]

Hi,
        On elephant gaits (last post from me, this is no longer
dinosaur-related and some of this is unpublished work), Betty rightly
pointed out that Muybridge noted elephants ambling.  In modern
biomechanical parlance, an "amble" is just a fast walk.  The taxonomy of
gaits sensu Muybridge and others is way oversplit.  I've read descriptions
of elephant locomotion that call the gait a walk, run, amble, pace, trot,
etc., etc....  As far as I can tell from first-hand observations and
quantified data (as well as hours spent scrutinizing Nature/National Geo
documentaries), they just walk.
        In regards to baby elephants, it's something we are investigating
but from the videos I've studied (including a lion attack on a baby
elephant, which escaped) they don't trot or pace (in a Hildebrandian
sense).  They just use a fast walk (lateral sequence with lateral
couplets).  The jargon I use is from M Hildebrand's work, such as "The
adaptive significance of tetrapod gait selection." American Zoologist
20:255-267 (1980).  This is what most contemporary researchers studying
animal locomotion use.
        Nonetheless, real data and not anecdotes are needed.  If you track
the "25-35 mph" speed estimates for elephants from the literature, they
mainly stem back to an old chap at the AMNH who saw an elephant moving and
thought it was Really Fast.  Not good science.

=====
        Switching gears, I agree that people need to go to Holtz's 1995
paper on the arctometatarsalian pes as a primary reference.  The
Encyclopedia of Dinosaurs article by myself and Padian is not primary
literature and is just a paraphrase of Holtz's work; there is NO original
research in there.  I don't know what I meant by "storing potential energy"
either (damned youthful indiscretion!), but that will be clarified in the
new book; try inserting "storing elastic strain energy" or something.

                                --John R. Hutchinson