Re: DINOSAUR STATISTICS re: Silesaurus

[Tetanurae@aol.com]

Seismosaurus@seznam.cz wrote:
<<Also, this year most dinosaur genera were described-29! (or 27 if 
*Sphaerotolus* is a junior synonym and *Silesaurus* isn't actually dinosaur).>>

I have coded (with generous help from Mickey Mortimer) _Silesaurus_ according 
to Sereno & Arcucci's 1994 matrix, Novas' 1996 matrix, a combined matrix of 
Sereno & Arcucci 1994 and Novas 1996, and Benton's 1999 matrix.  In all four 
cases Silesaurus came out as the sister taxon to {Ornithischia + Saurischia}.

In the one tree that included _Pseudolagosuchus_ (Novas 1996), it was even 
closer to the base of Dinosaurs than _Pseudolagosuchus_, which had been 
considered the immediate outgroup to dinosaurs.  I would have included 
_Pseudolagosuchus_ in all trees, but I don't have the primary literature, so I 
can't, 
although I suspect you'd find the same result.

There are a significant number of characters not present in _Silesaurus_ that 
are present in Dinosauria, so I really doubt it's a dinosaur SS.  On the 
other hand....  data from new basal taxa like _Saturnalia_, as well as adding 
characters suggested by David Marjanovic (I think) may change everything.

Pete Buchholz
Tetanurae@aol.com