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JON & ORNITHOLESTES



Jon Wagner has written us a long load of text on big 
non-coelurosaurian theropods. And he says...

> I don't think anyone who talks about a monophlyetic 
> Carnosauria thinks it includes tyrannosaurs, except maybe Norell and 
> Novacek.

What's your basis for this statement Jon? 

Regarding Paul Sereno and the Allosauroidea, Jon writes..

> He has not, to my knowledge, given a definition of Allosauroidea, he's just 
> labelled the
> node (IMHO, no priority for this sort of thing. Blind nodelabelling 
> is kind of annoying).

You shouldn't have said this Jon - Sereno et al. (1996 - the paper 
that describes the new _Carcharodontosaurus_ material 
and _Deltadromeus_) does include a diagnosis of 
Allosauroidea (in the notes and references section). One good derived 
allosauroid character they cite, incidentally, is lack of nasal 
participation in the antorbital fossa. And Jon - if you are 
interested in the systematics and morphology of carnosaurs, you MUST 
get hold of Harris (1998). It's one of the best theropod monographs 
ever, up there with Currie and Zhao (1994) and Gilmore (1920).

Something Jon does not note is Phil Currie's endorsement of a 
monophyletic Carnosauria. Though (to my knowledge), Currie has not 
published an in-depth analysis of the relationships of these 
theropods (yet), he has said that _Ceratosaurus_, sinraptorids and 
allosaurids do belong together (which means he is at discordance with 
the phylogeny in the Bakker, Williams and Currie _Nanotyrannus_ 
paper [where, if memory serves, acrocanthosaurs were basal 
tyrannosauroids]... but then that was a long time ago).
      
>The thing is, the line between derived "carnosaurs" and primitive 
>"coelurosaurs" is a little blurred. Look at the carnosaur-like 
>features of _Ornitholestes_ 

_Ornitholestes_ is one of the most poorly known of 'well known' 
theropods - Osborn's (1903, 1917) brief descriptions are inadequate, 
as are the reappraisals of Ostrom (1980) and Paul (1988a, 1998b), and 
Paul makes a few comments, and adds certain details in his 
reconstructions, that are at odds with Osborn's reconstruction (e.g. 
4 vs. 3 premax teeth). Goddam it, things are just a mess, with lots 
of half-truths and rumours floating around in the literature - we 
need a good monograph (and, of course, a number of theropod workers 
are fully aware of this). But what _has_ been described and figured 
so far is not carnosaur-like, so far as I can tell. (Well, Greg Paul 
(1988b - PDOTW) did mention that the lower limb bones were 'short'). 

Got to go. They're closing the office.

"What???"

DARREN NAISH
darren.naish@port.ac.uk