Re: Rhabdodon species

["Mickey Mortimer" <Mickey_Mortimer11@msn.com>]

Sven Sachs wrote-

> According to my information three species of Rhabdodon are considered
valid:
>
> 1. Rhabdodon priscus MATHERON, 1869
> 2. Rhabdodon septimanicus BUFFETAUT & LE LOEUFF, 1991
> 3. Rhabdodon robustus NOPCSA, 1900 (according to Le Loeuff, 1992)
>
> I would like to know; 1. is this still up to date and 2. could somebody
> provide me with the diagnostic features of R. septimanicus and R. robustus
?

R. septimanicus is only based on a dentary.  It was originally diagnosed by
the backwards sloping coronoid process, lack of a lateral shelf and curved
tooth row.  Brett-Surman (pers. comm. to Glut, 1991) thinks the sloping is a
preservational artifact and the curvature due to damage.  This makes me
doubt the validity of this species.  Le Loeuff (1992) considers R. robustus
to be distinct from R. priscus.  Pereda-Suberbiola and Sanz (1999) find that
there are several differences between French and Spanish remains (R.
priscus, R. septimanicus), and Romanian remains (R. robustus).  Characters
of R. robustus are- 50% smaller in size; anterolaterally projected
deltopectoral crest; lower dorsal neural spines; unfused sacral neural
spines; twisted humeral shaft; no obturator process; two depressions for
insertion of caudifemoralis longus on femur.  I think it sounds quite
probable that R. robustus is valid.  It must be noted however, that the
holotype of R. robustus is a dentary, which has not been shown to be
significantly different from R. priscus dentaries.  Thus, a new species may
have to be named with a distinctive holotype, or else a neotype might need
to be designated for R. robustus.

Mickey Mortimer