Re: neotheropod classification

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

Mickey Mortimer (Mickey_Mortimer11@msn.com) wrote:

<... Most of these have problems, as can be seen below-

<- semilunate made of single carpal. The more basal Coelurus has
this, but was not included in Sereno's study. So do
Acrocanthosaurus and many specimens of Allosaurus (Madsen,
1976), leaving me to wonder why carnosaurs are coded as 0.
Beipiaosaurus also has this, as do ornithomimosaurs(?) and
Mononykus.>

  Yes, *Gallimimus* possesses a slight trochlear surface to the
first and second carpals.

<- lacrimal ventral process anteriorly directed (primitive state
laterally directed) I must admit to not understanding this
character. It is ventrally directed in all theropods. Perhaps he
meant ventral to be the primitive state and the derived state
would be anteroventral. Or perhaps it's the direction the long
axis of the ventral process's cross section. I don't know.>

<- humeral deltoid depression broad and triangular. Not familiar
with this character, or detailed humeral anatomy. Segnosaurs are
conveniently coded as unknown for it though.>

  There is a very shallow region here, but the form is
indistinct as the deltoid depression (on cranial face of humerus
medial to deltopectoral crest) is undefined on all of it's
margins [which of course, doesn't exist :)]. Code it as
transformed; the same is for Ingenia, so I will assume this is
an interesting character, but functional.

  Overall, no gripes. I'm studying braincase anatomy, so I will
leave it to someone better informed to explain the sinovial
laterosphenoid joint. Needless to say, oviraptorids and
Avimimus, and many [most modern] birds, lack this as the skull
is completely fused. One can add *Itemirus* to this list, as well.

=====
Jaime A. Headden

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

__________________________________________________
Do You Yahoo!?
Get personalized email addresses from Yahoo! Mail
http://personal.mail.yahoo.com/