''Sulcavis'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 cla ...

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

s. One species is named, ''Sulcavis geeorum''. The fossil was found in

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 Pro ...

(121-125 million years ago) rocks in

Liaoning Liaoning () is a coastal province in Northeast China that is the smallest, southernmost, and most populous province in the region. With its capital at Shenyang, it is located on the northern shore of the Yellow Sea, and is the northernmost ...

Province, China. ''Sulcavis'' is the first discovery of a bird with ornamented

tooth enamel Tooth enamel is one of the four major Tissue (biology), tissues that make up the tooth in humans and many other animals, including some species of fish. It makes up the normally visible part of the tooth, covering the Crown (tooth), crown. The ...

. The enantiornitheans are unique among birds in showing minimal tooth reduction and a diversity of dental patterns. ''Sulcavis'' had robust teeth with grooves on the inside surface, which likely strengthened the teeth against harder food items. No previous bird species have preserved ridges, striations, serrated edges, or any other form of dental ornamentation.

Discovery

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 several ...

of ''Sulcavis'', BMNH Ph-000805, is discovered near the town of Lamadong, in Liaoning Province, China. The fossil was found in the

Yixian Formation The Yixian Formation (; formerly transcribed as Yihsien Formation) is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans the late Barremian and early Aptian stages of the Early Cretaceous. It is known for its ex ...

, an

rock formation A rock formation is an isolated, scenic, or spectacular surface rock outcrop. Rock formations are usually the result of weathering and erosion sculpting the existing rock. The term ''rock formation'' can also refer to specific sediment ...

. The genus was described on January 9, 2013, in an article that was published in the ''

Journal of Vertebrate Paleontology The ''Journal of Vertebrate Paleontology'' is a bimonthly peer-reviewed scientific journal that was established in 1980 by Jiri Zidek (University of Oklahoma). It covers all aspects of vertebrate paleontology, including vertebrate origins, evolu ...

'' by Jingmai Kathleen O'Connor, Yuguang Zhang, Luis Maria Chiappe, Qingjin Meng, Li Quanguo and Liu Di. 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 ...

of the new genus was named ''Sulcavis geeorum'' by the team of scientists. The genus name comes from the Latin words "sulcus" (groove) and "avis" (bird), reflecting the unusual dental characteristics of the genus. The species name is to honour the Gee family from La Cañada (US) "because of their generous contributions to the research of Mesozoic birds". The holotype of Sulcavis geeorum was prepared by Maureen Walsh at the Natural History Museum of Los Angeles County, USA.

Phylogeny

The

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 d ...

below follows O’Connor ''et al.'', 2013 phylogenetic analysis.

References

{{Taxonbar, from=Q2811254 Prehistoric birds of Asia Early Cretaceous birds of Asia Enantiornitheans Fossil taxa described in 2013 Paleontology in Liaoning