[D] Psittacosaurus lujiatunensis
Zhou, Gao, Fox, and Chen, 2006
Cretaceous Early Hauterivian
Ornithischia Genasauria Cerapoda Marginocephalia Ceratopia Neoceratopia Psittacosauridae
Yixian Formation, western Liaoning Province, China
Psittacosaurus (Osborn, 1923) = Protiguanodon (Osborn, 1923)
Psittacosaurus > Psittacosaurus guyangensis (Cheng, 1983)
Psittacosaurus > Psittacosaurus mongoliensis ( Osborn, 1923) = Psittacosaurus protiguanodonensis (Young, 1958) > Protiguanodon mongoliensis ( Osborn, 1923)
Psittacosaurus > Psittacosaurus osborni (Young, 1931) > Psittacosaurus tingi (Young, 1931)
Psittacosaurus > Psittacosaurus sinensis (Young, 1958) > > Psittacosaurus youngi (Chao, 1962)
Psittacosaurus > Psittacosaurus meileyingensis (Sereno, Chao, Cheng & Rao, 1988)
Psittacosaurus > Psittacosaurus xinjiangensis (Sereno & Chao, 1988)
Psittacosaurus > Psittacosaurus neimongoliensis (Russell & Zhao, 1996)
Psittacosaurus > Psittacosaurus mazongshanensis (Dong & Azuma, 1996)
Psittacosaurus > Psittacosaurus ordosensis (Russell & Zhao, 1996)
Psittacosaurus > Psittacosaurus lujiatunensis (Zhou, Gao, Fox, and Chen, 2006)
Psittacosaurus > Psittacosaurus sibiricus (Averianov, Voronkevich, Leshchinskiy, Fayngertz, 2006)
Psittacosaurus> Psittacosaurus major - (Sereno, Zhao, Brown and Tan 2007)
Psittacosaurus> Psittacosaurus gobiensis (Sereno, Zhao & Tan 2010)
Zhou, C -F., Gao, K-Q., Fox, R.C. and Chen, S-H. (2006) \\\\\\\"A New Species of Psittacosaurus (Dinosauria: Ceratopsia) from the Early Cretaceous Yixian Formation, Liaoning, China.\\\\\\\" Palaeoworld 15: 100-114.
Newly discovered, well-preserved skulls and mandibles from the lowest part of the Early Cretaceous Yixian Formation, western Liaoning Province, China, document the earliest known record of psittacosaurs and provide the basis for recognition of a new species, Psittacosaurus lujiatunensis. This discovery increases the taxonomic diversity of psittacosaurs to eight valid species and extends the stratigraphic range of the family Psittacosauridae from late Barremian-Albian to Hauterivian. Comparative study of the new species with other well-known Psittacosaurs indicates that the new taxon is probably the most basal member of the psittacosaur clade now known. This interpretation is in agreement with the temporal distribution of the clade and supports the hypothesis that the Psittacosauridae originated from the basal ceratopsian stem no later than the earliest part of the Cretaceous.
The specific epithet refers to the type locality.
ZMNH M8137, a nearly complete skull with lower jaws.
Type locality and horizon
Lujiatun, near Beipiao, Liaoning Province, China; lowest part of the Yixian Formation (Hauterivian, Early Cretaceous).
ZMNH M8138, a nearly complete, but somewhat compressed skull with lower jaws and the anteriormost three cervical vertebrae; PKUP V1053, a complete and slightly compressed skull and fragments of the lower jaws of a juvenile; PKUP V1054, a complete and slightly compressed skull with lower jaws, and proatlas and atlas of a young adult individual. All paratypes from the type locality and type horizon.
Differing from all other species of Psittacosaurus in the following combination of character states: large size; prefrontal narrow, less than 50% of width of nasal; maxillary protuberance upturned; jugal depression shallow; jugal horn arising relatively posteriorly and strongly developed posterolaterally; ventral ramus of squamosal contacting quadratojugal medial to quadrate; contact of jugal with quadrate narrow, overlapping quadratojugal; external mandibular foramen closed; angular large; maxillary tooth crowns trilobed, primary ridge enlarged into central lobe subequal to posterior lobe.
The holotype (ZMNH M8137) was threedimensionally preserved in coarse purple-red sandstones, with the mandibles in articulation with the skull. The skull is large, having a length of 190mm from the tip of the snout to the back of the quadrate, a maximum width of 250mm across the jugal horns and a maximum height of 145 mm. A second skull (ZMNH M8138) is even larger, having a maximum length of 205 mm. The skull of Psittacosaurus lujiatunensis n. sp. is wider than long as in Psittacosaurus sinensis Young, 1958 but differing from other psittacosaur species, in which the skull is longer than wide.