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_Neovenator_



        Reading the _Neovenator_ paper, I noticed one thing which did not
draw much comment from the authors, but which seems rather important:
        _Neovenator's_ ilium looks a heckuva lot like the ilium of
_Metriacanthosaurus_!  Specifically, they both have a sharply angled
postacetabular process.
        Further investigation of _Stokesosaurus_, which I have previously
suggested had a similar hip, shows that the ilium of that taxon only appears
to have the sharply angled postacetabular process when the ilium is viewed
at a slight angle (as the lower picture in Madsen 1976 shows).  This
character has also been attributed by Paul (_PDW_, 1988) to
_Yangchuanosaurus_, but _Y. magnus_ does not exhibit this condition, I have
yet to see a photo of _Y. shanyouenensis_ [sic], and the smaller species is
said to have a "distorted" ilium.  Indeed, Currie and Xiao [sic?] (1993)
suggest that the ilium of _Yangcuanosaurus_ is incorrectly restored, based
on the ilium of _Sinraptor_.  Considering the differences in the pelvi of
_S. dongi_ and _Yangchuanosaurus_, this statement is perhaps premature, but
for now the character is at least undiscernable in the latter taxon and
absent in the former.
        This suggests that this condition is a synapomorphy which links
_Metriacanthosaurus_ and _Neovenator_.  The vertebral spines of the latter
taxon are somewhat (around 20%?) lower than the former, and they are
different in other aspects, but of course it is not the differences which
concern us.  Tthis does suggest that least three seperate groups of
allosauroids (Sinraptoridae, Charcarodontosauridae, and Allosauridae) had
high-spined and low-spined morphs.

        Wagner
+--------------------------------------------------------------------------+
| Jonathan R. Wagner                    "You can clade if you want to,     |
| Department of Geosciences              You can leave your friends behind |
| Texas Tech University                  Because your friends don't clade  |
| Lubbock, TX 79409                               and if they don't clade, |
|       *** wagner@ttu.edu ***           Then they're no friends of mine." |
|           Web Page:  http://faraday.clas.virginia.edu/~jrw6f             |
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