HETERODONTOSAURS ~~AND~~ THE THIRD ANNUAL DINO-LIST GET TOGETHER

[Tetanurae@aol.com]

This is the second attempt I have made responding to this post.  Let's hope 
my computer won't crash wne I hit "send."

And of course leave it to ornithischians being brought up on the thero- errr 
dinosaur list to make Pete actually write a response to the list :-)

Dan Bensen wrote:

<<1)  What about Abrictosaurus?>>

Abrictosaurus is weird.  The drawing in Norman's 1985 book that a lot of 
people call Abrictosaurus, is not in fact Abrictosaurus, and was never called 
such in the text.  In fact, Abrictosaurus DOES have fangs, just not as 
prominent as in other Heterodontosaurids (or basal pachycephalosaurs).

There appear to only be two premax fangs, instead of three, and they are 
smaller.  The premax is incomplete however, so there may have been a third.  
Additionally, there is no dentary fang (and this is pretty certain because 
both dentaries are almost entirely intact), even though there is a big arched 
diastema like other heterodontosaurs (and pachycephalosaurs).  The rest of 
the skull is pretty incomplete, and I don't think the postcrania has yet been 
described, but what has been shows a very weird animal.

What does it mean though?  Well, it could be indicative of a distinct species 
of heterodontosaurid with odd dentition.  It could be a really weird, or 
deformed or younger version of a more "normal" heterodontosaur (or even a 
basal pachy).  It could be a "female" of another species of another "normal" 
heterodontosaur (or basal pachy).

What it is really?  I have no idea.  Thulburn cites that it has weird cheek 
tooth replacement patterns, so even if it is a weirdo or a "female" it is 
probably distinct from the other known heterodontosaurs.

<<2) What's this I hear about Heterodontosaurus being a prosauropod?>>

I've heard nothing about that...  I would say the chances are pretty darn 
unlikely.  They are pretty securely ornithischians, and pretty securely 
cerapodan ornithischians, based on numerous characters in the hand, face, and 
teeth.

<<4) Omnivory is the eccpeted diet of Heterodontosaurus, what sort of tubers 
and
 insects did it share its habitat with?  What did they look like?>>

I've never heard anyone suggest that heterodontosaurs were omnivores.  
Probably they would have eaten any low-lying vegitation: ferns etc.  The 
teeth are really weird, and designed for slicing, almost like scissors 
(similar to ceratopians), rather than simple teeth or a grinding battery 
(like iguanodontian ornithopods).

NOW

That you have waded through all that crap on heterodontosaur teeth and 
ornithischian facial evolution....  I would like to extend a warm invitation 
to everyone on the list attending SVP to come to the dino-list breakfast.  
Please, RSVP to Mary (mkirkaldy@aol.com) as soon as humanly possible for what 
is sure to be the most amazing non-professional paleontological breakfast 
ever.  I hope to see you all there.

Peter Buchholz
Tetanurae@aol.com