NON-CLUBBED SAUROPODS

[Tetanurae@aol.com]

Jaime Headden wrote:
<<As for sauropods, *Omeisaurus* is believed to own a
 club, a small series of oblate spheres fused to one another, that was
 found disarticulated from any skeleton, so we don't know for true if
 *Omeisaurus* (*O. fuxiensis*, to be exact) had a "club", if that's
 even the right word for it.>>

The only sauropod that actually has a club associated with the rest of the
skeleton is Shunosaurus lii.  Dong Zhiming has assigned some rather large,
non-associated tail clubs to the Omeisaurus species from the Lower Shaximiao.

There are some problems with this assignment:
1) The larger tail clubs are the right size to go with the largest specimens
of Shunosaurus so there is no "need" for them to be assigned to the bigger
Omeisaurus.
2) There are no tail clubs of this type (or any type) from the overlying Upper
Shaximiao Formation which also has Omeisaurus as well as its close relative
Mammenchisaurus.

This has led Paul Upchurch (pers comm 1997) to place great doubt on his
Euhelopodidae (Shunosaurus, Mammanchisaurus, Euhelopus, Omeisaurus) because
the major charcter linking them up actually existed in just one of the taxa.

Most everyone else has published cladograms that show Shunosaurus as being a
much more basal sauropod and Omeisaurus as the outgroup to Neosauropods.
Wilson and Sereno even make a good case (in my mind) that Euhelopus is
actually a basal titianosaur [with this I am assuming that had they ran
Mammenchisaurus, it would have claded with Omeisaurus].

Peter Buchholz
Tetanurae@aol.com