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RE: Megalosaurus = Torvosaurus in Europe



 
Stephan Pickering wrote:

> Compared with Ceratosauria, this revised Megalosauridae has a 
> combination of apomorphies related to increased size, 

I wonder, then, if these 'apomorphies' are not size-related homoplasies.
(Hasn't there been one or two papers drawing attention to this?)

> This Megalosauridae (in roughly chronological order: Megalosaurus
> nethercombensis, M. bucklandii, Metriacanthosaurus reynoldsi, M. brevis,
> Eustreptospondylus oxoniensis, Metriacanthosaurus parkeri, Megalosaurus
> phillipsi, Poecilopleuron bucklandii, Megalosaurus tanneri,
> Metriacanthosaurus shangyouensis) 

I don't know about the origins of "Metriacanthosaurus reynoldsi" or "M.
brevis" or "M. phillipsi", but _Metriacanthosaurus shangyouensis_ is Greg
Paul's combination for _Yangchuanosaurus shangyouensis_ Dong, Chang, Li and
Zhou,1978.  This referral of _Y. shangyouensis_ to the British genus
_Metriacanthosaurus_ has not been widely accepted.  

Several fairly recent papers have assigned _Yangchuanosaurus_ and a closely
related coeval theropod named _Sinraptor_ to the family Sinraptoridae.  The
two genera are very similar and may even be synonymous.  At any rate,
sinraptorids clearly appear more derived than the taxa usually identified as
megalosaurids, and closer to _Allosaurus_.


Tim


------------------------------------------------------------ 

Timothy J. Williams 

USDA-ARS Researcher 
Agronomy Hall 
Iowa State University 
Ames IA 50014 

Phone: 515 294 9233 
Fax:   515 294 3163