Re: Deltadromeus (was RE: Size of *Neoceratodus africanus* and/or *N. tuberculatus*)

[Tim Williams <tijawi@yahoo.com>]

Thomas R. Holtz, Jr. <tholtz@umd.edu> wrote:


> Carrano & Sampson (2008. The Phylogeny of Ceratosauria
> (Dinosauria:
> Theropoda). JSysPaleo 6:183-236) found Deltadromeus to be a
> basal ceratosaur
> rather than a noasaurid. If so, we would not expect it to
> to have any
> particularly Masiakasaurus-like skull features.


Thanks for that.  I guess I was just using _Masiakasaurus_ as an example of a 
ceratosaur that probably didn't target large prey.  Given the range of skull 
types present in theropods in general (and ceratosaurs are no exception - and 
not referring to _Masiakasaurus_ in particular), I still don't think we can be 
confident in assuming that _Deltadromeus_ attacked large prey.  The limb bones 
of _Deltadromeus_ are rather slender (the original description says they 
compare well to _Ornithomimus_).  So _Deltadromeus_ may have been built like 
the smaller _Elaphrosaurus_ - another basal ceratosaur, according to Carrano & 
Sampson (2008).  (I know none of this is news to the good Dr Holtz - I'm just 
hammering away at my original point... whatever it was.)


Incidentally, and on a complete tangent, Carrano & Sampson (2008) also note 
that "the holotypes of _Bahariasaurus_ and _Deltadromeus_ (as well as the 
specimens referred to the latter by Sereno et al. 1996) cannot be confidently 
distinguished at this time.  More complete materials from Egypt and Morocco are 
required before this issue can be settled."  I'd say there are long odds on 
_Deltadromeus_ surviving as a valid taxon.


Cheers

Tim