was a marginocephalia
Marginocephalia is a clade of ornithischian dinosaurs that includes the thick-skulled pachycephalosaurids, and horned ceratopsians. They were all herbivores, walking on two or four legs, and are characterized by a bony ridge or frill the back of the skull...
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
from the Late Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
(dated to between 150.8 and 145.5 million years ago). Chaoyangsaurus
belonged to the Ceratopsia
Ceratopsia or Ceratopia is a group of herbivorous, beaked dinosaurs which thrived in what are now North America, Europe, and Asia, during the Cretaceous Period, although ancestral forms lived earlier, in the Jurassic. The earliest known ceratopsian, Yinlong downsi, lived between 161.2 and 155.7...
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
for "horned faces"), a group of primarily herbivorous dinosaurs with parrot
Parrots, also known as psittacines , are birds of the roughly 372 species in 86 genera that make up the order Psittaciformes, found in most tropical and subtropical regions. The order is subdivided into three families: the Psittacidae , the Cacatuidae and the Strigopidae...
-like beaks which thrived in North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
during the Cretaceous Period (which ended roughly 65 million years ago). Chaoyangsaurus
, like all ceratopsians, was primarily a herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
Discovery and Species
was found in the Chaoyang area of Liaoning Province in northeastern China. The specific name honours the Chinese paleontologist C. C. Young
Yang Zhongjian , courtesy name Keqiang , also known as C.C. Young, was one of China's foremost paleontologists. He has been called the 'Father of Chinese vertebrate paleontology'...
Unlike many other dinosaurs, Chaoyangsaurus
had been discussed in a number of sources before its official publication. As a result of this, several different spellings of its name have come and gone as nomina nuda
The phrase nomen nudum is a Latin term, meaning "naked name", used in taxonomy...
("naked names", names with no formal description behind them). The first name to see print was Chaoyoungosaurus
, which appeared in the guidebook to a Japanese museum exhibit, and was the result of an incorrect transliteration. Zhao
Zhao Xijin is a Chinese paleontologist. He is notable for having named numerous dinosaurs. He is currently a professor at Beijing's Institute of Vertebrate Paleontology and Paleoanthropology.-Career:...
(1983) also used this spelling when he first discussed the species, so it is technically a nomen nudum
. Two years later, Zhao again used this early spelling when he assigned a type specimen and species name, Chaoyoungosaurus liaosiensis
According to Dong
Dong Zhiming , from the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, is one of China's leading paleontologists. He began working at the IVPP in 1962, learning from Yang Zhongjian who was director at the time...
(1992), the name Chaoyoungosaurus
had been officially described in a paper by Zhao and Cheng in 1983, but no cite for this supposed paper exists, and it is likely it was not properly published. Dong, in his 1992 paper on the subject, also emended the name to the "correct" spelling of Chaoyangosaurus
(note the extra letter "o"). However, since this re-naming was not accompanied by a formal description of the dinosaur, Chaoyangosaurus
must also be considered a nomen nudum
It was not until 1999 that the dinosaur finally received an official name. Sereno (1999) used the name Chaoyangsaurus
in an overview of ceratopsian taxonomy. Once again, that name was a nomen nudum
. However, in December of that year, Cheng, Zhao, and Xu published an official description using the name Chaoyangsaurus youngi
, and as the first name for this genus that is not a nomen nudum
, it has official priority over all other spellings that have been used.