Psittacosaurus phylogeny

["Alessandro Marisa" <amaris@tin.it>]

Recently I tentatively elaborate a phylogeny within the genus
Psittacosaurus, and I have seen that there are two possible subgroups within
the Psittacosaurus's species, divisible in the presence or absence of  jugal
horns; the subgroup with the absence of jugal horn include: P. mogoliensis,
P. meileyingensis and P. neimongoliensis and the subgroup with the presence
of jugal horn include: P. sinensis, P. youngi, P. xinjiangensis and P.
ordosensis. On these bases we have:

Psittacosauridae
|--P. mongoliensis
|--P. meileyingensis
|--P. neimongoliensis
+--P. sinensis
     |--P. youngi
     |--P. xinjiangensis
     |--P. ordosensis

Within the first subgroup P. mongoliensis is the most basal form because has
more than 10 teeth in maxillary and dentary, while P. meileyingensis and P.
neimongoliensis has 10 or less teeth in maxillary and dentary, for these the
two latter species seems more closely related to P. sinensis that to P.
mongoliensis, in support to this suggestion, P. meileyingensis share with P.
sinensis, P. xinjiangensis and P. youngi the closure of the antorbital
fenestra.
Any comment or suggestion?


P.S.
Could someone tell me if in P. mazongshanensis the jugal horn is present or
absent?

By
Alessandro Marisa
"Volunteer of Paleontological Museum of Monfalcone"
Via Achille Grandi n°18
38068 ROVERETO (TN) ITALY
Tel: 039-0464-434658 Email: amaris@tin.it