Judinornis is a prehistoric flightless bird

Flightless bird

Flightless birds are birds which lack the ability to fly, relying instead on their ability to run or swim. They are thought to have evolved from flying ancestors. There are about forty species in existence today, the best known being the ostrich, emu, cassowary, rhea, kiwi, and penguin...

 genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 from the Late Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

. The single known species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 is Judinornis nogontsavensis. Its fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

s have been found in Nemegt Formation

Nemegt Formation

The Nemegt Formation is a geological formation dating from the Late Cretaceous sedimentary from the Gobi Desert of Mongolia. It overlies and sometimes forms folds with the Barun Goyot Formation. It consists of river channel sediments and contains fossils of fish, turtles, crocodilians, birds and a...

 rocks of southern Mongolia

Mongolia

Mongolia is a landlocked country in East and Central Asia. It is bordered by Russia to the north and China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only from Kazakhstan's eastern tip. Ulan Bator, the capital and largest...

, and as the age of these deposits is not entirely resolved, Judinornis may have lived some 70 million years ago (mya) during the early Maastrichtian

Maastrichtian

The Maastrichtian is, in the ICS' geologic timescale, the latest age or upper stage of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned from 70.6 ± 0.6 Ma to 65.5 ± 0.3 Ma...

, or perhaps somewhat earlier, 76 mya, during the Campanian

Campanian

The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...

.

The Nemegt Formation does not seem to contain marine

Marine (ocean)

Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 sediments. Consequently and unlike its relatives, this was apparently a bird of estuaries and rivers running from the mountains thrown up by the Cimmerian orogeny

Cimmerian Orogeny

The Cimmerian Orogeny, is an orogeny that created mountain ranges that now lie in Central Asia. The orogeny is believed to have begun 200 - 150 million years ago , when the Cimmerian plate collided with the southern coast of Kazakhstania and North and South China, closing the ancient Paleo-Tethys...

 through the arid lands of continental East Asia

East Asia

East Asia or Eastern Asia is a subregion of Asia that can be defined in either geographical or cultural terms...

 towards the Turgai Sea

Turgai Sea

The Turgai Sea or Turgai Strait, also known as the West Siberian Sea, was a large shallow body of salt water of the Mesozoic and Cenozoic Eras...

 and the former Shigatze Ocean.

Judinornis was a member of the Hesperornithes

Hesperornithes

Hesperornithes is an extinct and highly specialized clade of Cretaceous toothed birds. Hesperornithine birds, apparently limited to former aquatic habitats in the Northern Hemisphere, include genera such as Hesperornis, Parahesperornis, Baptornis, Enaliornis, and probably Potamornis, all...

, flightless toothed seabirds of the Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

. Though its relationships to other members of this group are inadequately known, it appears to have been one of the more basal Hesperornithes.