''Asprosaurus'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

anguimorph The Anguimorpha is a suborder of squamates. The group was named by Fürbringer in 1900 to include all autarchoglossans closer to '' Varanus'' and ''Anguis'' than ''Scincus''. These lizards, along with iguanians and snakes, constitute the propos ...

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia al ...

from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korea, Korean Peninsula and sharing a Korean Demilitarized Zone, land border with North Korea. Its western border is formed ...

. Named in 2015 from the

Seonso Conglomerate Formation The Seonso Conglomerate is a Cretaceous aged geologic formation in South Korea. Fossil of ''Asprosaurus'', ''Koreanosaurus'' and dinosaur eggs have been reported from the formation. See also * List of dinosaur-bearing rock formations * List of ...

, the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen( ...

''Asprosaurus bibongriensis'' is the first

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Creta ...

lizard to have been discovered on the Korean peninsula. Because ''Asprosaurus'' is known only from fragmentary material, its relationships with other lizards are uncertain. However, features of the lower jaw suggest that it may be a member of a clade (evolutionary grouping) called

Monstersauria Monstersauria is a clade of anguimorph lizards, defined as all taxa more closely related to ''Heloderma'' than '' Varanus''. It includes ''Heloderma'', as well as several extinct genera, such as ''Estesia'', '' Primaderma'' and ''Gobiderma'', bu ...

, which includes the living

Gila monster The Gila monster (''Heloderma suspectum'', ) is a species of venomous lizard native to the Southwestern United States and the northwestern Mexican state of Sonora. It is a heavy, typically slow-moving reptile, up to long, and it is the only v ...

Size

''Asprosaurus'' is among the largest

terrestrial lizards from

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an ...

described to date, with an estimated skull length of , only rivalled by ''

Chianghsia ''Chianghsia'' is an extinct genus of monstersaurian platynotan lizard known from the Late Cretaceous deposits of the Nanxiong Formation, southern China. It contains a single species, ''Chianghsia nankangensis''. Its genus is named after Jiangxi ...

'' from China.

References

Late Cretaceous lepidosaurs of Asia Campanian life Santonian life Fossils of South Korea Fossil taxa described in 2015 {{cretaceous-reptile-stub