''Eleutherornis cotei'' is a medium-sized (estimated to be 1.5 meters tall)

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

flightless

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

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 ...

, in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Phorusrhacidae Phorusrhacids, colloquially known as terror birds, are an extinct clade of large carnivorous flightless birds that were one of the largest species of apex predators in South America during the Cenozoic era; their conventionally accepted temporal ...

or "terror birds" whose remains have been found in

Middle Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn ...

aged strata from

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

and

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

Discovery

The partial remains of this bird were discovered in France near Listeu, a municipality of the metropolis of Lyon and Switzerland in Egerkingen in the canton of Solothurn. They were reviewed and described in 2013 by Delphine Angst and his colleagues under the name of Eleutherornnis.

Description

It is a medium-sized phorusrhacid, with a height of about 1.50 meters that shows a combination of basal and derivative characters. Tarchlea of tarsometatarsus II is enlarged in its middle part as in psilopterines, while the pre-acetabulary of the ilium is more compressed laterally and more ventilated with neural spines of the synsacral vertebrae than in psilopterines, and thus recalls more the more evolved phorusrchacids.

Geography

It is the only known phorusrhacid in Europe and one of the few species of this family identified outside the Americas, although ''

Lavocatavis ''Lavocatavis'' is an extinct genus of phorusrhacoid or "terror bird" from the Eocene of Algeria. A fossilized femur was described from the Glib Zegdou Formation in 2011 and is the only known specimen of ''Lavocatavis''. The species was design ...

'' described in 2011 from Algeria, but whose membership of this family is debated.

References

Extinct flightless birds Eocene birds Phorusrhacidae Eocene birds of Europe {{paleo-bird-stub