RE: Introducing: Sinovenator changii

["Williams, Tim" <TiJaWi@agron.iastate.edu>]

Thomas R. Holtz, Jr. wrote:

>Enter _Sinovenator changii_, (Meeman Chang's China hunter) based on a
>partial skull and skeleton and a referred skeleton from the lowest part
>of the Yixian Formation.  [snip] Sadly, the horizon it is
>from does not preseve the integument of the critter, one way or the >other.

Sadly, also, the _Sinovenator_ specimen does not preserve the "sickle-claw"
on the foot.  Otherwise, the specimen provides very little to complain
about.

>Metatarsal III is somewhat constricted, but non-arctometatarsalian.

The authors state: "..the foot resembles more closely the
subarctometatarsalian condition seen in the basal dromaeosaurid
_Sinornithosaurus_ than the non-arctometatarsalian condition."

>The analysis includes species-level OTUs, which I won't reproduce
>entirely here.  

The topology of the species *within* the clades Therizinosauroidea,
Oviraptorosauria, Avialae and Dromaeosauridae are largely presented as
polytomies.  To answer David's question, the avialan OTU's are
_Archaeopteryx_, _Rahonavis_, _Confuciusornis_.

And, as Tom's post illustrates, Aves (and Avialae) is now put *inside*
Metornithes, since the Alvarezsauridae (which is monophyletic - surprise,
surprise) slips down the tree to become the sister taxon to an
"enigmosaur"-Paraves clade.

The troodontids seem finally to have found a home next-door to the
dromaeosaurids, in a monophyletic Deinonychosauria.  You see, if you only
wait long enough, all will be revealed.

Great stuff.


Tim





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

Timothy J. Williams 

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

Phone: 515 294 9233 
Fax:   515 294 3163