''Elaphrocnemus'' is a genus of extinct

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 lightweig ...

from the

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'', " ...

and Oligocene periods of

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

. Part of Cariamiformes, its closest living relatives are

seriemas The seriemas are the sole living members of the small bird family Cariamidae, which is also the only surviving lineage of the order Cariamiformes. Once believed to be related to cranes, they have been placed near the falcons, parrots and passer ...

, though it differs significantly from them, being a better flyer.

Classification

Since its original description ''Elaphrocnemus'' has been regarded as a cariamiform bird. It was referred to the family Orthocnemidae, since them absorbed into Idiornithidae.Cécile MOURER-CHAUVIRÉ, LES GRUIFORMES (A VES) DES PHOSPHORITES DU QUERCY (FRANCE). 1. SOUS-ORDRE CARIAMAE (CARIAMIDAE ET PHORUSRHACIDAE). SYSTÉMATIQUE ET BIOSTRATIGRAPHIE. However, relationships within Cariamiformes are unresolved, as several studies render Idiornithidae as

polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of conver ...

, with ''Elaphrocnemus'' recovered away from other "idiornithids", outside of the clade leading to them and modern

. Some authorities renders the genus a synonym of '' Talantatos'', though some recent studies recover it as independent from this genus. A possibly closely related species, '' Itaboravis'', is known from the

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

Flight capacities

Unlike its poorly-flighted modern

seriema The seriemas are the sole living members of the small bird family Cariamidae, which is also the only surviving lineage of the order Cariamiformes. Once believed to be related to cranes, they have been placed near the falcons, parrots and passerin ...

relatives, and the several flightless extinct Cariamiformes like

phorusrhacids 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 ...

and bathornithids, ''Elaphrocnemus'' appears to have been a good flyer. It possesses long scapulas, convergent in shape to those of

pelicans Pelicans (genus ''Pelecanus'') are a genus of large water birds that make up the family Pelecanidae. They are characterized by a long beak and a large throat pouch used for catching prey and draining water from the scooped-up contents before s ...

, and although its

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 ...

was as weakly developed as that of modern

and their flightless relatives it had proportionally large and strong wing bone elements.

Gerald Mayr Gerald Mayr is a German palaeontologist who is Curator of Ornithology at the Senckenberg Research Institute in Frankfurt am Main, Hesse. He has published extensively on fossil birds, especially the Paleogene avifauna of Europe. He is an expert on ...

Cécile Mourer-Chauviré Cécile Mourer-Chauviré (born 1939) is a French paleontologist specializing in birds of the Eocene and the Oligocene. In her early career, she discovered with her husband the Laang Spean cave site of prehistoric humans in Cambodia. Career Cé ...

, The peculiar scapula of the late Eocene Elaphrocnemus phasianus Milne-Edwards, 1892 (Aves, Cariamae), December 2008, Volume 88, Issue 2, pp 195-198 Likewise, its legs were also shorter than those of other Cariamiformes, implying a less cursorial lifestyle. Because Caramiformes had a more or less global distribution across the Paleogene, the flight capacities of ''Elaphrocnemus'' and kin might be of extreme relevance to the biogeographical distribution of the clade.

Palaeoecology

''Elaphrocnemus'' is one of the most common birds in sites like the Quercy Formation, perhaps indicating agglomeration in large flocks. The local climate was subtropical in nature, producing a rich rainforest ecosystem that included a large variety of mammal and bird species.

References

{{Taxonbar, from=Q16687697 Eocene birds Oligocene birds Prehistoric birds of Europe Prehistoric bird genera