Re: Suchosaurus, Baryonyx and Martinavis

[Denver Fowler <df9465@yahoo.co.uk>]

Tim Williams wrote:
>Buffertaut's own opinion on this is: "_Suchosaurus_ could be regarded as a 
>senior synonym of _Baryonyx_.  However, the type 
>specimen of _Suchosaurus cultridens_ has a strongly ribbed labial surface 
>whereas the teeth of the holotype of _Baryonyx 
>walkeri_ are smooth, or nearly completely so, labially, so that it cannot be 
>excluded that they belong to distinct taxa... 
>Moreover, as the type specimen of _Suchosaurus cultridens_ is a worn isolated 
>tooth, whereas _Baryonyx walkeri_ is based on 
>a large part of a skeleton, for practical purposes it seems advisable to go on 
>using the generic name _Baryonyx_ instead of 
>_Suchosaurus_."

Some of this is being discussed on my SVP poster (rather unfortunate that 
buffetaut's paper comes out right before my presentation), but I think 
Buffetaut is looking for an excuse to keep Baryonyx, rather than really coming 
up with a good defensible reason not to dump the genus for Suchosaurus: The 
good examples of troodon and carcharodontosaurus (mentioned by tim) are 
identical cases. 

Moreover, I would argue for a great deal of variation in the teeth of 
baryonychines: based on numerous morphologies, you could make a case for there 
being multiple species of baryonychines present in the Wessex Fm, UK... but 
certainly it is more parsimonious to suggest a single taxon with teeth varying 
through the jaw, and possibly ontogeny. Some teeth show strong 'fluting' (I 
think ribbing is misleading since they are talking about longitudinal ridges) 
on one or both sides of the crown, others show none, or very little. Some teeth 
are quite rounded and conical, with little posterior curving, others are more 
compressed.

Baryonyx is a junior synonym of Suchosaurus. Nevertheless, Baryonyx is a nicer 
name than Suchosaurus, although Suchosaurus is more descriptive... I suppose 
you could argue that Bary is in more general usage... but then collectors on 
the Isle of Wight, UK, were using the term Suchosaurus for baryonychid teeth,  
long before Baryonyx itself was even named. Furthermore, at the very least, if 
Suchosaurus can indeed be attributed to 
Baryonychidae/Baryonychinae-Spinosauridae (which it can).. then the 
nomenclature should recognise it as the senior taxon, thus 
Spinosauridae=Suchosauridae, Baryonychinae=Suchosaurinae etc. which I think is 
much better.

I still prefer the name Baryonyx.

There's gonna be some serious sinking suggested at SVP by the way.

;D

Denver.






Cheers

Tim
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