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Re: further data on Psittacosaurus major



Citation and abstract below, my comments after the bar-

====================

New data on cranial anatomy of the ceratopsian dinosaur Psittacosaurus major

Hai−Lu You, Kyo Tanoue, and Peter Dodson
Acta Palaeontologica Polonica 53 (2), 2008: 183-196
An exceptionally preserved skull and mandible of ceratopsian dinosaur
Psittacosaurus major revealed many anatomical details such as the
existence of an elliptical median interpremaxillary foramen, a
prominent neurovascular canal on the internal wall of the beak, long,
slightly divergent basipterygoid processes developed as vertical
blades with a deep cleft between them, and horizontally oriented
vomer. The new specimen shows two autapomorphies of An exceptionally
preserved skull and mandible of ceratopsian dinosaur Psittacosaurus
major revealed many anatomical details such as the existence of an
elliptical median interpremaxillary foramen, a prominent neurovascular
canal on the internal wall of the beak, long, slightly divergent
basipterygoid processes developed as vertical blades with a deep cleft
between them, and horizontally oriented vomer. The new specimen shows
two autapomorphies of Psittacosaurus major, the transversely narrow
dorsal skull roof and very prominent dentary flanges, confirming the
presence of two large−skulled psittacosaur species in the Lujiatun Bed
of the Lower Cretaceous Yixian Formation in Beipiao City, western
Liaoning Province, China, the long− and narrow−skulled P. major, 
and
broad−skulled P. lujiatunensis.

Key words: Dinosauria, Ceratopsia, Psittacosaurus, Cretaceous, Yixian
Formation, Liaoning, China

====================

Haven't had a chance to read this paper in detail, but the authors
plugged Psittacosaurus major and Psittacosaurus lujiatunensis into
Averianov et al.'s psittacosaur matrix to get the following topology:

--+--+--sinensis
   |   `--sibiricus
   `--+--+--lujiatunensis
       |   `--mazongshanensis
       `--+--major
           `--+--neimongoliensis
               `--+--ordosensis
                   `--+--meileyingensis
                       `--mongoliensis

I don't have Averianov et al.'s paper on hand, but it'd be interesting
to see how this topology could change (or not change) if the
characters and taxa were plugged into a larger dataset like
Makovicky's.

Nick

2008/6/14 Dawid Mazurek <dawidmazurek@wp.pl>:
> http://www.app.pan.pl/download.php?src=archive/published/app53/app53-183.pdf&token=72b4453491307bd2d093cf11b7da4fcc
>