''Elsornis'' is a genus of

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 ...

bird. Only one species has been named, ''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 preserve ...

skeleton found in the

Gobi Desert The Gobi Desert (, , ; ) is a large, cold desert and grassland region in North China and southern Mongolia. It is the sixth-largest desert in the world. The name of the desert comes from the Mongolian word ''gobi'', used to refer to all of th ...

Mongolia Mongolia is a landlocked country in East Asia, bordered by Russia to the north and China to the south and southeast. It covers an area of , with a population of 3.5 million, making it the world's List of countries and dependencies by po ...

. 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 ...

fossil has been given the catalogue 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 in Central Asia, Gobi Desert, dating from the Late Cretaceous period, about 75 million ...

, 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. Campa ...

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

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

, which was a character previously unknown in enantiornitheans. Chiappe et al. (2007) conclude from the proportions of ''Elsornis'' ' pectoral skeleton that it was flightless or nearly so. It may have glided like ''

Archaeopteryx ''Archaeopteryx'' (; ), sometimes referred to by its German name, "" ( ''Primeval Bird'') is a genus of bird-like dinosaurs. The name derives from the ancient Greek (''archaîos''), meaning "ancient", and (''ptéryx''), meaning "feather" ...

'', climbing in trees to pounce on its prey on the ground. However, if this is not the case, it may have hunted on the ground, snatching up small vertebrates and bugs. Like the other members of Avisauridae, it probably had small non-serrated teeth it used for hunting, and possibly scavenged the carcasses left by other, more formidable carnivores. 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 specific name "keni" honors Mr. Ken Hayashibara.

References

Bird genera Late Cretaceous birds of Asia Enantiornithes Fossil taxa described in 2007 Fossils of Mongolia Extinct flightless birds Taxa named by Luis M. Chiappe {{paleo-bird-stub