PSITTACOSAUR REFS AND PHYLOGENY

[Tetanurae@aol.com]

I am searching for the journals that the following psittacosaur species were
recently described:

_Psittacosaurus sattayaraki_ Buffetaut & Suteethorn, 1992 

and:

_P. ordosensis_ Russell & Zhao, 1996, _P. neimongoliensis_ Russell & Zhao,
1996, and _P. mazongshanensis_ Russell & Zhao, 1996.

I am assuming that the last three were published simultaniously...  I am also
working on a phylogeny within the genus _Psittacosaurus_, so far, I have the
(valid) pre-1990 species like:

|--Psittacosaurus mongoliensis (1)
+--+--Psittacosaurus meileyengensis (2)
   |--Psittacosaurus youngi (3)
   +--+--Psittacosaurus sinensis (4)
      +--Psittacosaurus xinjiangensis (5)

I have numbered them 1-5 because their species names are excrutiatingly long
and I don't feel like typing them out...  Species 2-5 share a completely
closed anteorbital fenestra that is in form different from that of basal
neoceratopians who still have a fenestra, or a prominent fossa.  The snouts
on species 2-5 have no fenestra or fossa, species 1 retains a fenestra and
fossa.

Then there is an unresolved trichotemy between 2, 3, and (4+5).  The only
other synapomorphy I have been able to see is the jugal horns on 4 and 5
which have an anterior surface that is nearly perpendicular to the skull's
midline in dorsal view.

Figure one (species 4, 5):
   ^
  /|\
_| | |_ ___J
\  |  /
 |_|_|

Figure two (species 1, 2, 3):

   ^
  /|\
 | | |
/  |  \ ___J
\  |  /
 |_|_|

These are VERY simplified diagrams illustrating the differing jugal horn
morphology in the psittacosaur species showing the skull in dorsal view.  The
'^' is the tip of the rostrum, and the featured labeled J is the right jugal
horn.

[If you are in AOL or another server that uses an asthetic un-equal area font
(rather than an equal area font), copy and paste the above diagrams (the
cladogram too) into a .txt document to see them properly.]

Anyways yes, once again psittacosaur species 1 is _P. mongoliensis_, species
2 is _P. meileyengensis_, species 3 is _P. youngi_, species 4 is _P.
sinensis_, and species 5 is _P. xinjiangensis_.

And thanks again in advance for the full cites for _Psittacosaurus
sattayaraki_, _P. ordosensis_, _P. neimongoliensis_, and _P.
mazongshanensis_.

Peter Buchholz
Tetanurae@aol.com

One day I didn't eat for four days