RE: New dinosauriform paper

[Tim Williams <twilliams_alpha@hotmail.com>]

William Parker wrote:

> Also of interest in this analysis is
> the positioning of Eoraptor as the basal-most theropod and Herrerasaurus
> and Staurikosaurus as a clade of basal saurischians.  This placement for
> Eoraptor differs from the recent findings of Langer and Benton (2006) and
> Rauhut (2003), where Eoraptor is outside of Theropoda.  The new topology is
> also of interest as Ezcurra and Novas (2006) had earlier found Eoraptor and
> Herrerasaurus to be basal theropods and thus more closely related.

Other interesting things include coelophysoids and ceratosaurians recovered 
as successively closer to Tetanurae, leading to the revival of clade 
Averostra (Ceratosauria+Tetanurae).  Also, the analysis fails to find a 
monophyletic 'silesaur' group, nor (as for previous analyses) a 'Lagosuchia' 
clade.

My 'take' on the way that _Eoraptor_ and herrerasaurids keep on bouncing 
around the base of the Dinosauria (basal dinosaurs, basal saurischians, 
basal theropods, or even non-dinosaurs) is that the position(s) of these 
taxa are not well supported (statistically), and the analysis is having 
trouble pinning down these guys with any confidence.  Then again, I'm 
currently hideously jetlagged so my opinion could be complete nonsense.

Cheers

Tim

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