Re: Afrovenator abakensis

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

>   _Dryptosaurus aquilunguis_ does have the large thumb ungual, and the
>referred metatarsal and humerus look much like a megalosaur's, so it might 
>be a torvosaurid, despite its appearance in the latest Cretaceous.

Dryptosaurus is clearly coelurosaurian, especially when tibial and
metatarsal material is taken into account.  Look forward to a multiauthored
paper on Dryptosaurus coming soon to the JVP.

>   I noticed that tetanurans (from torvosaurs on up) tend to have
>opisthocoelous cervical vertebrae.  Can anyone corroborate this?  The 
>only exceptions I've found are _Gasosaurus_ and _Kaijiangosaurus_.  The 
>rest of the bones look tetanuran, but they have platycoelous cervicals.  
>Perhaps they are more primitive than the rest?  Are there any cervicals 
>referred to _Megalosaurus_?

Many coelurosaurs lack opisthocoelous cervicals, but yes, many of the
megalosauroids and carnosaurs do.

>   In general, I agree with Sereno's assessment.  Apart from _Gasosaurus_ 
>and _Kaijiangosaurus_ (which might just pertain to the same species), 

(As is, probably, "Szechuanosaurus" zigongensis)

>tetanurans appear to fall into three groups:
>
>Tetanurae
>   _Gasosaurus_/_Kaijiangosaurus_

Indeed!  Did you see my SVP talk?

>   Torvosauria
>      Eustreptospondylidae
>      Torvosauridae
>      ?Spinosauridae (?incl. _Baryonyx_)

The presence of Megalosaurus bucklandi in here changes "Torvosauridae" to
"Megalosauridae", but I agree with this grouping.

>   Allosauria
>      Sinraptoridae
>         Piatnitzkysaurinae (_Piatnitzkysaurus_, _Iliosuchus_, 
>                             _Stokesosaurus_)
>         Sinraptorinae
>         Monolophosaurinae (_Monolophosaurus_, _Cryolophosaurus_)
>      Allosauridae
>      Carcharodontosauridae

I'm not too keen on the Piatnitzkysaurinae, and (in my analyses, at least)
Monolophosaurus falls outside the Sinraptorid+Allosaurid clade, but I agree
with most of this.  Also, I have gone back to using "Carnosauria" for this
clade (Allosaurus and all theropods closer to Allosaurus than to birds).

>   Coelurosauria
>
>   BTW, what is the current consensus (ha, ha) on 
>_Chilantaisaurus_--torvosaur or allosaur?  Does _C. maortuensis_ belong 
>to this genus?

Personally, I'd answer "allosauroid, tentatively" and "no strong evidence to
unite the two".

>   I'm also not quite sure where _Megalosaurus_, _Magnosaurus_, and
>_Kelmayisaurus_ might belong.

I haven't gotten around to dealing with the latter two yet.

Take care,

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