Re: Torvosaurus & Giganotosaurus

[<TWILLIAMS@canr1.cag.uconn.edu>]

There may be a clade of basal tetanurines united by very short 
but very stocky forearm (antebrachial) elements, and perhaps certain 
other characters (such as of the vertebrae).  This group would 
include _Torvosaurus_, _Eustreptospondylus_, _Xuanhanosaurus_, and 
_Marshosaurus_ (based on a preliminary description of this 
genus presented at a fairly recent SVP meeting).  These are burly, 
robust theropods with powerful shoulder girdles - but both these 
characters may be primitive for the Tetanurae.

This clade could be called Megalosauridae, because many researchers 
have identified a close relationship between _Megalosaurus_ and 
_Torvosaurus_.  Unfortunately, _Megalosaurus_' postcranium is not 
well-known.  This may be one of the reasons why this family of 
big, stocky-armed, primitive tetanurines has been called the 
Torvosauridae by some.  

I believe there is a redescription of the genus _Megalosaurus_ in the 
works across the Atlantic.  Maybe this will help clarify things.


Tim