''Elaphrocnemus'' is a genus of extinct

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

from the

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

and

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

periods of

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

. Part of

Cariamiformes Cariamiformes (or Cariamae) is an order of primarily flightless birds that has existed for over 50 million years. The group includes the family Cariamidae (seriemas) and the extinct families such as Phorusrhacidae, Bathornithidae, Idiornithid ...

, its closest living relatives are

seriemas The seriemas are the sole living members of the small bird family Cariamidae (the entire family is also referred to as "seriemas"), which is also the only surviving lineage of the order Cariamiformes. Once believed to be related to cranes, they ...

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

Classification

Since its original description ''Elaphrocnemus'' has been regarded as a

cariamiform Cariamiformes (or Cariamae) is an order of primarily flightless birds that has existed for over 50 million years. The group includes the family Cariamidae (seriemas) and the extinct families such as Phorusrhacidae, Bathornithidae, Idiornithidae a ...

bird. It was referred to the family Orthocnemidae, since them absorbed into

Idiornithidae Idiornithidae is an extinct family of Cariamiformes Cariamiformes (or Cariamae) is an order of primarily flightless birds that has existed for over 50 million years. The group includes the family Cariamidae (seriemas) and the extinct families ...

.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 that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

, 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 (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

Flight capacities

Unlike its poorly-flighted modern

seriema The seriemas are the sole living members of the small bird family Cariamidae (the entire family is also referred to as "seriemas"), which is also the only surviving lineage of the order Cariamiformes. Once believed to be related to cranes, they ...

relatives, and the several flightless extinct

phorusrhacids Phorusrhacids, colloquially known as terror birds, are an extinct family of large carnivorous, mostly flightless birds that were among the largest apex predators in South America during the Cenozoic era. Their definitive fossil records range from ...

and

bathornithids Bathornithidae is an extinct family of birds from the Eocene to Miocene of North America. Part of Cariamiformes, they are related to the still extant seriemas and the extinct Phorusrhacidae. They were likely similar in habits, being terrestria ...

, ''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 ...

, and although its

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 ...

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.Mayr, Gerald (2016). ...

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

had a more or less global distribution across the

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

, 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