ALLOSAURS ARE A MESS

[darren.naish@port.ac.uk]

I have no definitive opinion on the taxonomy of _Allosaurus_ and its 
closest relatives - who has? - but with regard to what Tim Williams 
wrote...

> Bakker has not shown that these two species are distinct genera - at 
> least not in any scientific publication.  The name "Madsenius" was 
> proposed for certain _Allosaurus_ specimens which he considered 
> distinct from "true" _Allosaurus_.   I've also heard that another 
> _Allosaurus_ specimen has been tagged as a new genus by Bakker, with 
> the name "Wyomingraptor" proposed for this one.    

I thought 'Wyomingraptor' was a torvosaur. No, I am not getting 
confused with _Brontoraptor_ (which almost certainly is a torvosaur).

With due respect, Bakker appears to contradict himself regarding the 
interrelationships of allosaurs. For example, when talking about 
successives waves of big theropod evolution and extinction (as in 
last year's SVP - see _JVP_ 17: 30A), he argues that allosaurs are a 
very closely knit group of species exhibiting very little 
diversification. The implication is that the differences observed in, 
say, the Como ?taxa, are indicative of recent speciation and 
characters differentiating populations are probably not worthy of 
generic status. Yet, as we all know, at the same time he sees very 
similar allosaurs apparently different enough to deserve their own 
genera.. _Creosaurus_ and _Epanterias_. 

Add to this that the type specimen for _Allosaurus fragilis_ is 
poorly described and hardly defined. I am not convinced by Smith's 
study and I still think _Saurophaganax_ is quite a different beast 
from _Allosaurus_. I personally don't think that _A. fragilis_ and 
_A. (=Creosaurus) atrox_ are the same species either.. but then what 
do I know.

"One has only to wash one's hair after taking active part in 
dissecting a hippo to appreciate the advantage of baldness"

DARREN NAISH
darren.naish@port.ac.uk