''Yuxisaurus'' (meaning "

Yuxi Yuxi ( zh, c=玉溪, p=Yùxī) is a prefecture-level city in the central part of Yunnan province of the People's Republic of China. The administrative center of Yuxi is Hongta District. Yuxi is approximately south of Kunming. Geography Yuxi i ...

lizard") is an extinct genus of basal

thyreophora Thyreophora ("shield bearers", often known simply as "armored dinosaurs") is a group of armored ornithischian dinosaurs that lived from the Early Jurassic until the end of the Cretaceous. Thyreophorans are characterized by the presence of bod ...

n dinosaur from the

Early Jurassic The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic� ...

(

Sinemurian In the geologic timescale, the Sinemurian is an age (geology), age and stage (stratigraphy), stage in the Early Jurassic, Early or Lower Jurassic epoch (geology), Epoch or series (stratigraphy), Series. It spans the time between 199.5 ±0.3 annu ...

Toarcian The Toarcian is, in the International Commission on Stratigraphy, ICS' geologic timescale, an age (geology), age and stage (stratigraphy), stage in the Early Jurassic, Early or Lower Jurassic. It spans the time between 184.2 Megaannum, Ma (million ...

)

Fengjiahe Formation The Fengjiahe Formation is a geological formation in China. It dates back to the Early Jurassic, most likely to the Pliensbachian. The formation is up to 1500 metres thick and consists of "purple-red mudstone and argillaceous siltstone interbedd ...

of southwestern

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. The type species is ''Yuxisaurus kopchicki.''

Discovery and naming

''Yuxisaurus'' was first named in a ''

bioRxiv bioRxiv (pronounced "bio-archive") is an open access preprint repository for the biological sciences co-founded by John Inglis and Richard Sever in November 2013. It was hosted by Cold Spring Harbor Laboratory (CSHL) until March 11, 2025, whe ...

'' preprint released in late 2021, but was not considered valid, due to having not been validly published. The taxon was formally published shortly thereafter, in March 2022. The holotype of the taxon, CVEB 21701, represents a partial skeleton including parts of the skull, several vertebrae, elements of the limbs, and at least 120 osteoderms. The generic name, "''Yuxisaurus''," combines a reference to the type locality in

Yunnan Province Yunnan; is an inland Provinces of China, province in Southwestern China. The province spans approximately and has a population of 47.2 million (as of 2020). The capital of the province is Kunming. The province borders the Chinese provinces ...

, China, with the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

"sauros," meaning "lizard." The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, "''kopchicki''," honors the biologist John J. Kopchick.

Classification

''Yuxisaurus'' was a basal thyreophoran. Depending on the dataset, it may be the sister taxon to the German ''

Emausaurus ''Emausaurus'' is a genus of thyreophoran or armored dinosaur from the Early Jurassic (Early Toarcian). Its fossils have been found in the Lehmhagen Member, in Mecklenburg-Vorpommern, northern Germany. ''Emausaurus'' is the only known Toarcian t ...

'' or more basal than ''

Scelidosaurus ''Scelidosaurus'' (; with the intended meaning of "limb lizard", from Greek / meaning 'rib of beef' and ''sauros''/ meaning 'lizard')Liddell & Scott (1980). Greek-English Lexicon, Abridged Edition. Oxford University Press, Oxford, UK. is a ge ...

'' and eurypods. The discovery of ''Yuxisaurus'' definitively proves that thyreophorans were present in Asia during the Early Jurassic, as other potential records of Early Jurassic Asian thyreophorans, ''

Bienosaurus ''Bienosaurus'' (meaning "Bien's lizard") is a dubious genus of thyreophoran dinosaur from the Lower Jurassic (probably Sinemurian) Lower Lufeng Formation in Yunnan Province in China. Discovery and species The Lufeng Basin in China has bee ...

'' and ''

Tatisaurus ''Tatisaurus'' is a genus of ornithischian dinosaur from the Early Jurassic from the Lower Lufeng Formation in Yunnan Province in China. Little is known as the remains are fragmentary. The type species is ''T. oehleri''. Discovery and species ...

'', are too fragmentary to be of any significance. Topology 1: Norman dataset Topology 2: Maidment ''et al.'' dataset

References

{{Taxonbar, from=Q109997024 Thyreophora Dinosaur genera Sinemurian dinosaurs Toarcian dinosaurs Dinosaurs of China Fossil taxa described in 2022 Taxa named by Xu Xing