Re: Broader than Dinosauria [Additional Info]

["Jaime A. Headden" <qilongia@yahoo.com>]

Thanks to Adam Yates for providing information on *Saturnalia*'s pelvis, and 
allowing me to
confirm an hypothesis. A partially open medial acetabular wall, in the form of 
the triangular
apse, does appear to be a dinosaurian synapomorphy, even if it seems to have 
been convergently
expanded within Dinosauria. This does not contradict the use of the character.

  I'm only hoping that more complete information on *Eoraptor* is in the 
offering as well, and new
finds continue to supplement our understanding....

  As Ken is confronted with the large deltopectoral crest, _partially_ open 
acetabulum, and
ascending process of the astragalus as likely synapomorphies of the clade 
represented by the
formula {*Marasuchus* + Dinosauria}, it seems the major innovation of 
{Dinosauria <- *Marasuchus*}
is the features of the femur and tarsus indicating increased terrestrial 
bipedal cursorial
locomotion and the loss of the postparietal fenestra (questionable in 
*Lewisuchus*, since
parietals are absent from the specimen), that there are in fact secure 
synapomorphies for
Dinosauria. As Pete Buchholz points out, the "twist" thumb also appears to be a 
{Dinosauria <-
*Marasuchus*} synapomorphy.


=====
Jaime A. Headden

  Aaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhr-gen-ti-na
  Where the Wind Comes Sweeping Down the Pampas!!!!

__________________________________________________
Do You Yahoo!?
Get email alerts & NEW webcam video instant messaging with Yahoo! Messenger
http://im.yahoo.com