Re: Piatnitzkysaurus

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

>A recent message on the list suggested that just about all South American 
>Theropods were Ceratosaurs. What about Piatnitzksaurus? I have seen no 
>recent literature on this genus. In the original description Bonaparte 
>described the maxilla as having an acessory antorbital fenestra, does 
>this make it more likely that it is a tetanuran?

Although Phil Currie thinks that Piatnizkysaurus is an ancestral abelisaurid
(I don't know what characters he uses for this statement), others (including
Fernando Novas, Bernardino Perez-Moreno, and myself) find Piatnizkysaurus as
a basal tetanurine, outside of the Allosauroid-Coelurosaur clade.  In fact,
I find it outside of the Megalosauroid+(Allosauroid+Coelurosaur) clade, way
down at the base of Tetanurae.

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