new papers

[高橋 和男 Kazuo TAKAHASHI <pantheon@dino-pantheon.com>]

ACTA GEOLOGICA SINICA vol.79 No.2
pp.157-163

A New Ornithocheirid from the Early Cretaceous of Liaoning Province, China
LU Junchang and JI Qiang
Abstract
  Based on a nearly complete skeleton with skull from the Early Cretaceous
of Liaoning Province, a new
ornithocheirid pterosaur: Boreopterus cuiae gen. et sp. nov. is erected.
Boreopterus cuiae is different from other pterosaurs
preserved with skulls known from the western Liaoning Province and its
neighboring areas. This new pterosaur has more
and larger teeth than those in other ornithocheirids. Its anterior nine
pairs of teeth are larger than other teeth. The fourth pair
of upper and lower teeth are slightly larger than the third pair. Overall,
Boreopterus cuiae shows much small range of tooth
sixe variation than Anhanguera piscator and coloborhynghus robustus. The new
taxon shares with other ornithocheirids in
having a relatively large size of the third and fourth pairs of teeth.

pp.164-167
A new Ctenochasmatid Pterosaur from the Early Cretaceous of Liaoning
Province
DONG Zhiming and LU Junchang
Abstract
  Based on a nearly complete lower jaw from the Early Cretaceous of Liaoning
Province, a new ctenochasmatid
Pterosaur: Liaoxipterus brachyognathus gen. et sp. nov. is erected.
Liaoxipterus Brachyognathus is different from any
Known pterosaurs with skulls preserved from western Liaoning Pro vince and
its peripheral areas in that the anterior part of
The mandibular symphysis is expanded, being widest between the fourth
alveolus of each side. Liaoxipterus Brachyognathus
is assigned to Ctenochasmatidae based on the following characters: the
rounded anterior end of the lower jaw is
spatulated and dorsoventrally flattened and marked heterodonty in the
dentition is absent. It differs from other ctenochasmatid
pterosaurs in having relatively small number of teeth. Liaoxipterus is
distinguished from some ornithocheirids, which have
expanded anterior parts of the mandibular symphyses, such as Anhanguera
piscator, Coloborhynchus robustus in which the
teeth of the new pterosaur are not as variable.

pp.168-173
An Adult Specimen of Hongshanosaurus houi (Dinosauria: Psittacosauridae)
from the Lower Cretaceous of Western Liaoning
Province, China
YOU Hailu and XU Xing
Abstract  A new specimen consisting of a complete skull and lower jaw was
discovered from the Lujiatun bed of the
Lower Cretaceous Yixian Formation in the Lujiatun site, Beipiao, western
Liaoning Province. It represents an adult specimen of
Hongshanosaurus houi. Comparative studies show that Hongshanosaurus is
distinguishable from its sister taxon Psittacosaurus
by having the preorbital portion about half of the basal skull length, and
the elliptical external naris, orbit, and a lower temporal
fenestra oriented caudodorsally.

National Science Museum Monographs No.26
ISSN 1342-9574

A NEW SPECIMEN OF APATOSAURUS AJAX
(SAUROPODA: DIPLODOCIDAE) FROM
THE MORRISON FORMATION (UPPER JURASSIC)
OF WYOMING, USA

Paul Upchurch, Yukimitsu Tomida, and Paul M. Barrett
National Science Museum, Tokyo December, 2004

Abstract
 In 1993, a nearly complete postcranial skeleton of Apatosaurus was
recovered from the Morrison Formation (Upper Jurassic: Kimmeridgian -
Tithonian) near Thermopolis, Wyoming (USA). This specimen was purchased
by the National Science Museum, Tokyo, where it has been mounted for
public display. Description of this new Apatosaurus material has yielded
additional anatomical data that have been used to revise the generic
diagnosis
and species-level taxonomy of the genus. A specimen-level cladistic analysis
of individuals referred to Apatosaurus identifies hitherto unrecognized
phylogenetic structure and indicates the presence of four valid species:
A. ajax (the type species), A.excelsus, A.louisae, A.parvus (comb. nov.).
The latter species is based on material of ‘Elosaurus’ parvus 
from the
Morrison
Formation of Sheep Creek, Wyoming (USA). The cladistic analysis indicates
that the Tokyo Apatosaurus can be referred to A. ajax, which makes the
current study the most detailed description of this genotype species.
Revised generic and specific diagnoses have allowed re-evaluation of various
Specimens that have previously been assigned to Apatosaurus, including
juvenile material from Oklahoma.

 TALAHASHI, Kazuo

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