Chaoyangsaurus
Named after Chaoyang, the region in Liaoning Province, China where fossils were found, + Greek sauros ('lizard'), meaning 'Chaoyang lizard'.
Late Jurassic and Early Cretaceous stages
Chaoyangsaurus is a genus of marginocephalian dinosaur from the Late Jurassic (about between 150.8 and 145.5 million years ago) of China. Chaoyangsaurus belonged to the Ceratopsia (Greek for "horned faces"). Chaoyangsaurus, like all ceratopsians, was primarily a herbivore.
Diagnosis
- Quadratojugal overlaps the posterior (caudal) surface of the quadrate shaft rather than its lateral surface.
- Quadrate shaft lacks a broad lateral surface; lateral margin is very thin anteroposteriorly with no anterior ramus.
- Posteroventral margin of the quadrate shaft is convex mediolaterally, not concave or planar as in other ornithischians.
- Dorsal margin of the lower jaw extends nearly horizontally from the coronoid process to the jaw articulation, with ventral margin curving posterodorsally along the angular region.
- A distinct ridge separates the planar lateral and ventral surfaces of the angular, which meet at approximately a right angle.
Species
Chaoyangsaurus youngi Zhao et al., 1999
Type species
Named for the Chinese paleontologist Yang Zhongjian (known as 'C. C. Young'), regarded as the founder of Chinese vertebrate paleontology.
- Holotype
- IGCAGS V371 , Institute of Geology, Chinese Academy of Geological Sciences
- Material
- Dorsal part of a skull, nearly complete mandible, complete axis, an isolated cervical vertebra and five articulated cervicals, a fragmentary humerus and scapula.
- Horizon
- Tuchengzi Formation, Tithonian–Berriasian, Late Jurassic–Early Cretaceous , 149.2–137.1 million years ago
- Locality
- Ershijiazi, Liaoning, China
References
- Zhao, X.; Cheng, Z.; Xu, X. (1999). The earliest ceratopsian from the Tuchengzi Formation of Liaoning, China. Journal of Vertebrate Paleontology 19(4): 681-691. Informa UK Limited. doi:10.1080/02724634.1999.10011181 zhao1999a