Re: Diplodocoidea vs. Diplodocimorpha

["Mickey Mortimer" <Mickey_Mortimer111@msn.com>]

Mike Taylor wrote-

> Dear DMLers,
>
> I have one more request.  I am interested in the group Diplodocimorpha
> as used at both the Dinosauricon and the Dinosauria On-Line websites:
> http://dinosauricon.com/taxa/diplodocimorpha.html
> http://www.dinosauria.com/dml/clado/diplodocimorpha.html
>
> The Dinosauricon cites the definition {Diplodocus > Saltasaurus}, but
> doesn't give a reference for it; and the Dinosauria On-Line cladogram
> doesn't give a definition but has comparable content.
>
> I'd understood that this definition was usually named Diplodocoidea,
> but the Dinosauricon uses this for a diplodocimorph subclade, defined
> as {Diplodocus + Dicraeosaurus}, also without a reference.  This group
> omits the rebbachisaurs according to prevailing phylogenies.  And
> again, the Dinosauria On-Line cladogram is congruent with this,
> although there's no definition given.
>
> My questions: can anyone tell me the reference for Diplodocimorpha?
> And does anyone know who is responsible for the narrower node-based
> definition of Diplodocoidea?

Diplodocomorpha Calvo and Salgado, 1995
Reference- Calvo, J.O. and L. Salgado. 1995. Rebbachisaurus tessonei sp.
nov., a new Sauropoda from the Albian-Cenomanian of Argentina: new evidence
on the origin of the Diplodocidae. Gaia 11: 13-33.

Diplodocoidea was named by Upchurch (1995) for his nemegtosaurid +
dicraeosaurid + diplodocid clade.  I don't know if he defined it, my copy is
at home.  Rebbachisaurids were not considered a distinct primitive clade
yet, as Rayososaurus tessonei had yet to be described.  Once it was, Calvo
and Salgado (1995) continued using Diplodocoidea for the more restricted
clade, and created Diplodocomorpha for the more inclusive clade of
(Rayososaurus tessonei + Diplodocus longus) (modified).  I'm not sure if
they defined both clades either (I don't have that paper), though the
commentary in Glut (2000) suggests they at least defined Diplodocomorpha as
(Rebbachisaurus + Diplodocidae).  Nobody seems to have followed their usage
though, and continued using Diplodocoidea for the more inclusive clade.
Wilson and Sereno (1998) defined Diplodocoidea as (Diplodocus longus <-
Saltasaurus loricatus) (modified).  We'll have to see if Upchurch (1995) or
Calvo and Salgado (1995) defined it earlier.

Mickey Mortimer