Re: Re: Euhelopodidae

[Thomas_R_HOLTZ@umail.umd.edu (th81)]

>From: GSP1954@aol.com
>
> > 2 - Big reptiles that do drag their tails on the ground do not have
> > forked chevrons.
>
> > The animals that do have forked chevrons are the giant ground
> > sloths, which very probably used their tails as props when they feed
> > on two legs.  Sauropods probably did the same thing.
>
>This may be the best evidence yet for the upright feeding posture
>in diplodocids and euhelopids.  It is indeed notable that the forked
>chevrons occur in just those sauropod families that are most often
>considered to have reared up to feed, and are absent in those families
>that fairly clearly fed giraffe-style.

Alternatively, Charig (and later, Upchurch) have associated the forked
chevron (basis for the name _Diplodocus_, by the way) with the use of the
tail as a weapon.  At least some diplodocids had whiplike tails, and those
euhelopodids for whom the tip of the tail is known show tail clubs.

(Incidentally, this suggests that not only has the neck orientation and head
structure been incorrectly restored on nearly every illustration of
_Mamenchisaurus_, but futher that the tail of this Chinese sauropod probably
ended in club as well.  "Crossing the Flats" by Henderson (I think) might be
a dramatic picture, but it does not reflect current knowledge of
_Mamenchisaurus_).

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:th81@umail.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661