''Dunhuangia'' is a bird

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 ...

, belonging to the

Enantiornithes The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct avialans ("birds" in the broad sense), the most abundant and diverse group known from the Mesozoic era. Almost all retained teeth and cl ...

, which during the

Early Cretaceous The Early Cretaceous (geochronological name) or the Lower Cretaceous ( chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pr ...

lived in the area of present China. In 2015, Wang Min,

Li Daqing Li, li, or LI may refer to: Businesses and organizations * Landscape Institute, a British professional body for landscape architects * Leadership Institute, a non-profit organization located in Arlington, Virginia, US, that teaches "political tec ...

, Jingmai Kathleen O'Connor,

Zhou Zhonghe Zhou Zhonghe (; born 19 January 1965 in Jiangdu, Jiangsu province) is a Chinese palaeontologist. He described the ancient bird ''Confuciusornis''.. Zhou graduated from Nanjing University and earned a Ph.D. in Biology in 1999 from the University o ...

and

You Hailu In Modern English, ''you'' is the second-person pronoun. It is grammatically plural, and was historically used only for the dative case, but in most modern dialects is used for all cases and numbers. History ''You'' comes from the Proto- ...

named and described 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( ...

''Dunhuangia cuii''. The generic name refers to the city of

Dunhuang Dunhuang () is a county-level city in Northwestern Gansu Province, Western China. According to the 2010 Chinese census, the city has a population of 186,027, though 2019 estimates put the city's population at about 191,800. Dunhuang was a major ...

in Gansu province. 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 ...

honours preparator Cui Guihia.M. Wang, D. Li, J. K. O'Connor, Z. Zhou and H. You. 2015. "Second species of enantiornithine bird from the Lower Cretaceous Changma Basin, northwestern China with implications for the taxonomic diversity of the Changma avifauna". ''Cretaceous Research'' 55: 56-65 The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

, GSGM-05-CM-030, was found in the

Changma Basin The East Asian Monsoon is a monsoonal flow that carries moist air from the Indian Ocean and Pacific Ocean to East Asia. It affects approximately one-third of the global population, influencing the climate of Japan, the Korean Peninsula, Taiwan, Ch ...

, in a layer of the

Xiagou Formation The Xiagou Formation is the middle strata of the Xinminbao Group. It is named for its type site in Xiagou, in the Changma Basin of Gansu Province, northwestern China and is considered Early Cretaceous in age. It is known outside the specialized ...

dating from the

Aptian The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ag ...

. It consists of a partial skeleton lacking the skull. It contains the forelimbs, shoulder girdle and sternum. It is partly articulated. ''Dunhuangia'' is a medium-sized

enantiornithean The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct avialans ("birds" in the broad sense), the most abundant and diverse group known from the Mesozoic era. Almost all retained teeth and cl ...

. The describing authors established some

autapomorphies In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to t ...

, unique derived traits. The rear edge of the sternum has a pair of large notches, equalling over half of the length of the entire element. The

coracoid A coracoid (from Greek κόραξ, ''koraks'', raven) is a paired bone which is part of the shoulder assembly in all vertebrates except therian mammals (marsupials and placentals). In therian mammals (including humans), a coracoid process is pre ...

has a deep trough in the top, bordered on the outside by a thick ridge which forms the vertically low outer bone wall of the element. ''Dunhuanagia'' was placed in the Enantiornithes, as

sister species In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

of '' Fortunguavis''. It is only the second enantiornithean species named from the Changma Basin of which the bird fauna largely consists of

Ornithuromorpha Euornithes (from Greek ' meaning "true birds") is a natural group which includes the most recent common ancestor of all avialans closer to modern birds than to ''Sinornis''. Description Clarke ''et al''. (2006) found that the most primitive kno ...

. This can be explained by the fact that the basin consists of coastal deposits while Enantiornithes are arboreal species.

References

{{Taxonbar, from=Q30501137 Early Cretaceous birds of Asia Euenantiornitheans