Re: D-SHAPED TEETH

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

Nick Pharris wrote:

> _Indosuchus_ has D-shaped premax teeth (though I suppose the Tendaguru is a 
> little early to be looking for abelisaurs).

Maybe not.  According to Phil Currie, _Piatnitzkysaurus_ is an abelisaur.  
(I still have it pegged as a basal tetanurine though.)

Anyway, looking at cladograms for the ceratosaurians, irrespective of 
whether the Abelisauria is the sister taxon to _Ceratosaurus_ or 
_Elaphrosaurus_, both were around in the Late Jurassic (and both in the 
Tendaguru), so abelisaurs split off from the rest of the Ceratosauria 
probably during the first half of the Jurassic (if not earlier).  Like basal 
marginocephalians, we just haven't found them in the Jurassic yet.  (Or, for 
both marginocephalians and abelisaurs, they have been found in the Jurassic, 
but not recognised as such.)



Tim

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