RE: New papers on the dinosaur formerly known as Syntarsus (no more "Megapnosaurus")

[Tim Williams <twilliams_alpha@hotmail.com>]

Brad McFeeters wrote:

> The first paper mentions "Megapnosaurus" as a junior synonym of 
> *Coelophysis*, but with surprisingly brief comment... "Analysis of the 
> newly discovered skull has demolished each of these purported characters, 
> leading us to concur with Paul (1988 1993) that i) *Syntarsus* is a junior 
> synonym of *Coelophysis*, and ii) that the recently proposed facetious 
> replacement name for *Syntarsus* (*Megapnosaurus* Ivie, Slipinski & 
> Wegrzynowicz, 2001) should not stand."

The nomenclatural issue is separate from the phylogenetic/taxonomic issue.  
_Megapnosaurus_ is a valid name, since Ivie et al. (2001) followed ICZN 
guidelines for providing a replacement name for _Syntarsus_ Raath, 1969 (non 
_Syntarsus_ Fairmaire 1869).  The fact that Raath was not given the 
opportunity to do this himself is unfortunate, but does not subtract from 
the validity of _Megapnosaurus_.  (Unless the ICZN deems it to be so in 
response to an official petition.)  I hate the name _Megapnosaurus_,  and I 
regret the way it was named - and I'm glad it's sunk into _Coelophysis_.  
But this is another issue, tied up with phylogeny and taxonomy: as a 
subjective junior synonym of _Coelophysis_, the *genus* _Megapnosaurus_ is 
invalid.  But the *name* itself valid, and it will stand as the available 
name for _S. rhodesiensis_ unless overturned by fiat by the ICZN.

> From Bristowe and Raath (2004):

> Reconstruction and analysis of a skull from a juvenile specimen of 
> *Syntarsus* (collected from the Forest Sandstone Formation of Zimbabwe) 
> shows thar cranial characters previously used to distinguish these taxa and 
> justify their generic separation (namely the presence of a 'narial 
> fenestra' in *Syntarsus* and the length of its antorbital fenestra), were 
> based on erroneous reconstructions of disassociated cranial elements.  On 
> the basis of this reinterpretation we conclude that *Syntarsus* is a junior 
> synonym of *Coelophysis*.

I believe Alex Downs found the exact same thing, a few years back.  He also 
regarded _S. rhodesiensis_ as a species of _Coelophysis_.

Nick Pharris wrote:

> >"Syntarsus" *rhodesiensis* and "S." *kayentakatae* are reclassified as 
> species of *Coelophysis*.
>
>
> *kayentakatae*, too?  In the popular literature, this critter is often 
> portrayed as rather different from *bauri* and *rhodesiensis*.  Is it not 
> so?

I was going to ask the same question.  After all, _kayentakatae_ does have 
nasolacrimal crests.  OK, these crests are much lower than those of 
_Dilophosaurus_, but they are there nonetheless.

Cheers

Tim