''Elsornis'' is a genus of

enantiornithine 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. Only one species is known, ''Elsornis keni''. It lived during the Late Cretaceous. It is known from a partially articulated

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

skeleton found in the

Gobi Desert The Gobi Desert (Chinese: 戈壁 (沙漠), Mongolian: Говь (ᠭᠣᠪᠢ)) () is a large desert or brushland region in East Asia, and is the sixth largest desert in the world. Geography The Gobi measures from southwest to northeast an ...

Mongolia Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...

. 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 ...

fossil is given catalog number MPD - b 100/201. It is in the collection of the Mongolian Palaeontological Center. The fossil was collected at Togrogiin Shiree, South Gobi Aimak, Mongolia;

Djadokhta Formation The Djadochta Formation (sometimes transcribed and also known as Djadokhta, Djadokata, or Dzhadokhtskaya) is a highly fossiliferous geological formation situated in Central Asia, Gobi Desert, dating from the Late Cretaceous period, about 75 milli ...

, Late Cretaceous,

Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian s ...

. The fossil is extremely well preserved in three dimensions. It preserves a pneumatized

Furcula The (Latin for "little fork") or wishbone is a forked bone found in most birds and some species of non-avian dinosaurs, and is formed by the fusion of the two pink clavicles. In birds, its primary function is in the strengthening of the thoracic ...

, which was a character previously unknown in enantiornithines. Chiappe et al. (2007) conclude from the proportions of ''Elsornis'' ' pectoral skeleton that it was flightless or nearly so. A study by Atterholt ''et al.'' in 2018 places ''Elsornis'' in the family '' Avisauridae''.

Etymology

The Genus name Elsornis is derived from the Mongolian word "Els", meaning "sand", and "ornis", the Greek word for "bird". The species name "keni" honors Mr. Ken Hayashibara.

References

Bird genera Late Cretaceous birds of Asia Enantiornitheans Fossil taxa described in 2007 Fossils of Mongolia Extinct flightless birds {{paleo-bird-stub