Ozraptor and Kakuru - Aussie abelisaurs?

[Tim Williams <twilliams_alpha@hotmail.com>]

Apologies in advance if this paper has been mentioned previously on this 
list (I seem to have missed some recent posts):

Rauhut, O.W.M. (2005).  Post-cranial remains of 'coelurosaurs' (Dinosauria, 
Theropoda) from the Late Jurassic of Tanzania. Geol. Mag. 142: 97?107.

It contains a lot of info about isolated theropod bones from Tendaguru in 
Tanzania.  No new genera or species are described.  Very interesting, with 
the Tendaguru theropod fauna dominated by different ceratosaurs.  Some 
elements hitherto identified as 'coelurosaurs' are re-identified as small 
abelsiaurs.

Rauhut briefly discusses two Australian theropods, _Ozraptor_ (Middle 
Jurassic) and _Kakuru_ (Early Cretaceous), which have proven difficult to 
classify.  A small tibia (MB.R 1750) from Tendaguru is identified as coming 
from a small abelisauroid, and shares with _Ozraptor_ "the derived character 
of a depressed, subdivided facet for the ascending process of the 
astragalus".  Thus, _Ozraptor_ is identified as a Middle Jurassic 
abelisauroid.  If the identification is correct, it indicates a pre-Bajocian 
divergence for ceratosaurids and abelisauroids.

The little theropod _Kakuru_ has a "flattened anterior side of the distal 
end of the tibia with a medial vertical ridge", which Rauhut mentions as 
possible synapomorphies of small abelisauroids.

A third Aussie theropod, _Rapator_, is mentioned as a possible abelisaur, 
and Rauhut cites Molnar (1992).  However, there is good evidence that the 
isolated "metacarpal" of _Rapator_ is in fact the phalanx of a large 
alvarezsaurid (Holtz et al., 2004).



Tim