[D] Psittacosaurus [Su] [sG]
Cretaceous Early Berriasian Valanginian Hauterivian Barremian Aptian Albian
Ornithischia Genasauria Cerapoda Marginocephalia Ceratopia Neoceratopia Psittacosauridae
Genus - Skull
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)
(\\\\\\\\\\\\\\\"parrot lizard\\\\\\\\\\\\\\\") a two-legged herbivore that resembled the ornithopod Hypsilophodon, but had a deeper, longer body, a shorter tail, longer arms, and four -fingered, grasping hands. The fourth finger and the first of the four toes were very short. But Psittacosaurus\\\\\\\\\\\\\\\'s oddest feature was its short. deep head with a parrot-like beak, formed partly by the rostral bone unique to ceratopians.
Psittacosaurus sattayaraki (Buffetaut & Suteethorn, 1992) is based on a partial dentary ans possible a fragment of the maxilla. Given the poor preservation of the dentary and its dubious association with the supposed maxillary fragment assignment to a new genus of uncertain phylogenetic affinity is not warrented. \\\\\\\\\\\\\\\"Psittacosaurus\\\\\\\\\\\\\\\" sattayaraki is tentatively reffered to Ceratopia incertae sedis. (Sereno, 2000)
Zhou, C.-F. & Fox, R. (2006) A lattice-like pattern of ossified tendons in Psittacosaurus (Dinosauria - Ceratopsia) JVP 26(3) Abstracts pp. 143
Ossified tendons are important in studying the musculoskeletal system and behaviors of dinosaurs. Since Dollo’s description of dinosaur ossified tendons in 1886, the pattern of ossified epaxial tendons is best known in iguanodonts and hadrosaurids. In this study, an ossified tendon lattice is described in Psittacosaurus from the Lower Cretaceous Yixian Formation in Liaoning Province, China, furnishing new information on epaxial musculature evolution in archosaurs.
In Psittacosaurus, the epaxial tendons are well developed in tight bundles along dorsal and sacral regions of the vertebral column. As in iguanodontoids, the tendons form a threelayered lattice. The mid-layer is formed by posteroventrally-oriented tendons, and both outer and inner layers by posterodorsally-extending tendons. A similar pattern is known for the neoceratopsian Chasmosaurus.
Recent studies show that the lattice in Iguanodontidae, Chasmosaurus, and avians, has lost the innermost, M. multifidus, layer, a derived character for Dinosauria; these clades, retain the more lateral M. spinalis and M. semispinalis components of M. transversospinalis in crocodilians and lepidosaurs.
These findings in Psittacosaurus extend the epaxial tendon lattice among Ceratopia, strenthening the hypothesis that the similar epaxial musculature in Cerapoda is derived for Dinosauria.