MESSAGE
| DATE | 2013-05-01 |
| FROM | Ruben Safir
|
| SUBJECT | Subject: [NYLXS - HANGOUT] Re: Definitions of running (was RE: RE: Complaining)
|
I am forwarding you this detailed conversation on Biomechanics that is
raging on the Dinosaur Mailing List. Please see my Commentary about
half way down...
On Tue, Apr 30, 2013 at 09:46:08PM -0400, GSP1954-at-aol.com wrote:
> "We do find evidence that elephants run in a sense,"
>
> said first author John Hutchinson, a Stanford
>
> postdoctoral research fellow in the Department of
>
> Mechanical Engineering. "It's an intermediate
>
> sort of gait, but it looks like what we
>
> biomechanically would call running. They don't leave
>
> the ground, which is the classical definition, but
>
> they do seem to bounce, which is the biomechanical
>
> definition."
>
> The problem with saying that elephants can run is that elephants cannot
> really run the way most mammals can. Saying animals can either just walk or can
> run is to simplistic, there are as above notes transitional forms like
> elephants that have barely some running attributes, but are much slower than
> most mammals and cannot even trot like hippos much less gallop like rhinos (not
> a simple size thing, an adult horse the same mass as a juvenile elephant is
> almost three times faster, its the flexed limbs and perhaps mass dedicated
> to locomotion that makes the difference).
>
> The way it should work is this.
>
> If an animal cannot achieve "a bounce" nor a suspended phase then it cannot
> run and is only walking (fits salamanders I think, turtles, maybe the
> biggest sauropods since even just walking their long strides could have gotten
> them to the elephant max of 15 mph).
>
> If it can achieve a bounce in a least one set of limbs but cannot bounce
> enough to get all feet off the ground at the same time then it is semirunning
> or ambling (elephants, unitatheres, most sauropods, derived stegosaurs).
>
> If it can achieve enough bounce to get all feet off the ground then it is
> achieving a full or true run (bipedal run, hopping, trot, pace, canter,
> gallop)
You forgot skipping. Have you ever seen an elephant skip?
http://www.youtube.com/watch?v=ERymFcS-fCg
> (most limbed reptiles, most all dinosaurs including giant theropods,
> giant ornithopods, giant ceratopsid, big ankylosaurs [albeit barely], many
> birds, most mammals including hippos [they can really haul all that fat around on
> those dinky limbs, no point in trying to outrun one], brontotheres,
> indricotheres).
>
> GSPaul
>
> | |
