Chilantaisaurus (was Re: "Megalosaurus" inexpectatus the carcharodontosaurid?)

["Timothy Williams" <twilliams_alpha@hotmail.com>]

Nick Pharris wrote:

> Harris reports that Chure (pers. comm.) considers that the braincase of
> _Chilantaisaurus_ has been misdescribed and does not consider "the 
> material"
> allosauroid at all.  Jerry, I'm curious: is it just the braincase that 
> Chure
> considers non-allosauroid, or the whole taxon?  Does he have any other
> suggestion for what it might be?

The problem is that the two species (_C. tashuikoensis_, _C. maortuensis_) 
do not appear to be closely related.  _C. tashuikoensis_ (type species) is 
possibly an allosauroid; the humerus is very _Allosaurus_-like, although 
proportionately much larger - _Allosaurus_ and _Chilantaisaurus_ appear to 
be of similar body size, but the humerus of _Chilantai_ is double the length 
of the humerus of _Allosaurus_.  The femur and ilium (what is known of it) 
are also _Allosaurus_-like too.

The braincase you mention comes from _C. maortuensis_.  The cranial material 
shows coelurosaurian features.  From a previous posting (March 99), from 
Darren Naish:

"I think we can say that they *certainly* do not belong in the same
genus: _C. tashuikouensis_, the type species, is probably a
non-coelurosaur (a megalosauroid or a spinosauroid?), while _'C'
maortuensis_ was referred to the Maniraptora by Dan Chure (1998).
Chure cited reduced number of maxillary teeth, small and fused
maxillary interdental plates and (among other features) a highly
pneumaticised basicranium. This was in the JVP 18 abstracts volume - 
[snip]."



Tim
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