BARYONYX TEETH

[darren.naish@port.ac.uk]

Hello all, happy 2002 and all that.

In between lecturing and (ostensibly) paper and thesis writing, I'm 
reading _The Armored [sic] Dinosaurs_. I'm confused by something in 
Tracy and Jim's paper on _Aletopelta_: they describe some of the 
scutes as 'pup tent' shaped. Question: what the hell is a pup tent? 
(Is it where baby seals get killed?)

Moving on, re: variation in _Baryonyx_ teeth, Mickey M asked...

> Damn all this variation :-) .  A few questions-
> Suchomimus seems to have very similar microtexture, does anyone know
> if Spinosaurus or Irritator do?  

I've looked at _Irritator_ but unfortunately without a microscope - and 
you need this to see the enamel microtexture (obviously). The 
_Spinosaurus_ teeth I have seen (keep in mind though, they are 
isolated) do not have the same microtexture as _Baryonyx_.

> By "faceting", do you mean fluting.  

Yes: I prefer the word 'faceting', largely because it is less problematic 
to translate into non-English.

> Where do these teeth come from?  

Wealden of Bexhill, Surrey.

If anything has become clear from seeing the many baryonychid teeth in 
collections that I now have, it's that (1) ID cannot be made in the hand 
and (2) one feature cannot alone be relied upon as definitive evidence 
of ID. I should also mention that there are Isle of Wight Wessex Fm 
teeth that match _Baryonyx_ in DSDI etc but lack faceting on both 
lingual and labial sides. 

The variation is probably due to tooth position, though ontogeny might 
play a part as (e.g.) the non-faceted tooth is small enough to come 
from a juvenile. Another possibility, hinted at by Ruiz-Omenaca et al., 
is that the tooth variation seen in the European baryonychids is 
indicative of multiple species. More on this in the next issue of Dino 
Press.

Finally, _Lacerta vivipara_ is now often called _Zootoca vivipara_.

DARREN NAISH 
PALAEOBIOLOGY RESEARCH GROUP
School of Earth & Environmental Sciences
UNIVERSITY OF PORTSMOUTH
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