''Dunhuangia'' is a bird

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

, belonging to the

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

, which during the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

lived in the area of present

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 ...

. In 2015, Wang Min, Li Daqing, Jingmai Kathleen O'Connor,

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

and You Hailu named and described the

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

''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. Sachu (Dunhuang) was ...

Gansu Gansu is a provinces of China, province in Northwestern China. Its capital and largest city is Lanzhou, in the southeastern part of the province. The seventh-largest administrative district by area at , Gansu lies between the Tibetan Plateau, Ti ...

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 (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

, GSGM-05-CM-030, was found in the Changma Basin, 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 (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), S ...

. 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 ...

, 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 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 present as part of the scapula, but this is n ...

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 the enantiornithines. This group was defined in the ''PhyloCode'' by Juan Benito and ...

. 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 Enantiornithes