''Daqingshanodon'' is an extinct genus of

dicynodont Dicynodontia is an extinct clade of anomodonts, an extinct type of non-mammalian therapsid. Dicynodonts were herbivorous animals with a pair of tusks, hence their name, which means 'two dog tooth'. Members of the group possessed a horny, typic ...

therapsid Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more ...

from the

Late Permian Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, ...

Inner Mongolia Inner Mongolia, officially the Inner Mongolia Autonomous Region, is an autonomous region of the People's Republic of China. Its border includes most of the length of China's border with the country of Mongolia. Inner Mongolia also accounts for a ...

, China. 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 specime ...

''D. limbus'' was described in 1989 from a single skull found in the

Naobaogou Formation The Naobaogou Formation is a geological formation in the Daqing Mountains of China. It is likely of Lopingian age. It consists of three rhythms of sediment, labelled members I-III primarily of purple siltstone Siltstone, also known as aleurol ...

. ''Daqingshanodon'' belongs to a group of dicynodonts called cryptodonts. It is the smallest known cryptodont, and the only one known from China. Like other cryptodonts, it has a pair of rounded nasal bosses above its nostrils and a ridge of bone on the upper jaw called the postcaniniform process. ''Daqingshanodon'' has a pair of elongated, recurved tusks extending from its beak-like snout. It is distinguished from other dicynodonts by the presence of a distinct ridge running along the side of the skull from below the eye socket to the area around the tusks. The skull of ''Daqingshanodon'' is less than long, yet this specimen is thought to have been an adult on the basis of its well-developed nasal bosses. In his 1998 study of dicynodont biogeography, paleontologist Spencer G. Lucas synonymized ''Daqingshanodon'' with ''

Dicynodon ''Dicynodon'' ("two dog-teeth") is a genus of dicynodont therapsid that flourished during the Upper Permian period. Like all dicynodonts, it was herbivorous animal. This reptile was toothless, except for prominent tusks, hence the name. It proba ...

'', forming the species ''Dicynodon limbus''. Most of the features used to distinguish ''Daqingshanodon'' as a distinct genus were also seen in specimens of ''Dicynodon''. In 2011, a study of ''Dicynodon'' species included ''D. limbus'' in its

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

analysis. ''D. limbus'' was placed among the cryptodonts, which are only distantly related to ''Dicynodon''. With this phylogenetic placement, the genus ''Daqingshanodon'' was reinstated for ''D. limbus''. Below is a

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

from the 2011 analysis:

References

{{Taxonbar, from=Q5221837 Permian synapsids of Asia Dicynodonts Lopingian synapsids of Asia Anomodont genera