Massospondylus

[Tim Williams <twilliams_alpha@hotmail.com>]

My apologies if this has already been mentioned...

Sues, H.-D., Reisz, R.R., Hinic, S., and Raath, M.A. (2004).  On the skull 
of _Massospondylus carinatus_ Owen, 1854 (Dinosauria: Sauropodomorpha) from 
the Elliot and Clarens formations (Lower Jurassic) of South Africa.  Annals 
of Carnegie Museum. 73(4): 239-257.

ABSTRACT: This paper presents a comprehensive description of the cranial 
structure of the sauropodomorph dinosaur _Massospondylus carinatus_, based 
oil four well-preserved skulls (including one of a juvenile individual) from 
the Lower Jurassic Elliot and Clarens formations of South Africa. 
_Massospondylus_ can be distinguished from other basal sauropodomorph 
dinosaurs by the following combination of primitive and derived cranial 
character-states: The greatest transverse width of the skull exceeds its 
dorsoventral height by at least 10 percent. Even in adult specimens, the 
orbit is proportionately large and the antorbital region proportionately 
short. The maxilla has a tall, nearly vertical dorsal process, and its 
medial sheet is narrow anteroposteriorly. A long posterior process of the 
prefrontal extends along the dorsal margin of the orbit, but the frontal 
still participates significantly in the formation of the orbital margin. 
There is a distinct ridge on the dorsolateral aspect of the lacrimal and a 
knob on the lateral surface of the prefrontal. A partial skull from the 
Lower Jurassic Kayenta Formation of Arizona previously attributed to 
_Massospondylus_ differs from the South African material in several cranial 
and dental features and is not referable to this taxon.