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Re: EUROPEAN ALLOSAURS



At 03:40 PM 2/3/97 +0000, Darren Naish wrote:
>_Neovenator_ is rather complete - approx. 70% of the skeleton is known. It has
>avetheropodan characters (e.g. large pubic boot) and is assigned to the
>Allosauroidea Sereno et al., 1994, (am I right in thinking that the taxon Tom
>calls Carnosauria is the same?)

Not quite.  Carnosauria (as I and Padian use it) is a stem-based taxon
(Allosaurus and all theropods closer to Allosaurus than to modern birds),
while Allosauroidea (as I and Padian use it) is a node-based taxon (all
descendants of the most recent common ancestor of Allosaurus and Sinraptor).
In most (all?) current cladograms, Allosauroidea is a node within Carnosauria.

>on the basis of a nasal that participates in the
>antorbital fossa. Postcranial characters of the Allosauridae (as per Holtz,
>1994) are present in _Neovenator_: however 'We cannot tell if these
features are
>present or absent in the Sinraptoridae' (p. 641), so for that reason Hutt
et al.
>are not 100% about the animal being an allosaurid.

I like the fact that Neovenator has five premaxillary teeth (as does
Allosaurus, but not Sinraptor or any other carnosaur).  That might be a good
character for Allosauridae, in which case Neovenator is an allosaurid.  Will
have to see how it all falls out in the matrix, though.

>In their systematic
>description it is listed as Family ?Allosauridae. Also, their definition of
>Allosauridae follows that of Holtz, 1994, when _Acrocanthosaurus_ was included
>(whereas it's now away from _Allosaurus_ and in a Carcharodontosauridae). Tom
>might like to comment on that bit as I'm a bit confused.

Well, Acro isn't THAT far away: carcharodontosaurids seem to be good
carnosaurs and probably allosauroids.

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

"To trace that life in its manifold changes through past ages to the present
is a ... difficult task, but one from which modern science does not shrink.
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