Elaphrocnemus is a genus of extinct bird from the Eocene and Oligocene periods of Europe. Part of Cariamiformes, its closest living relatives are seriemas, though it differs significantly from them, being a better flyer.
Since its original description Elaphrocnemus has been regarded as a cariamiform bird. It was referred to the family Orthocnemidae, since them absorbed into Idiornithidae. However, relationships within Cariamiformes are unresolved, as several studies render Idiornithidae as polyphyletic, with Elaphrocnemus recovered away from other "idiornithids", outside of the clade leading to them and modern seriemas.
Unlike its poorly-flighted modern seriema relatives, and the several flightless extinct Cariamiformes like phorusrhacids and bathornithids, Elaphrocnemus appears to have been a good flyer. It possesses long scapulas, convergent in shape to those of pelicans, and although its furcula was as weakly developed as that of modern seriemas and their flightless relatives it had proportionally large and strong wing bone elements. 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.
Elaphrocnemus is one of the most common birds in sites like the Quercy Formation, perhaps indicating aglommeration 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.
- Joel Cracraft 1973
- Cécile MOURER-CHAUVIRÉ, LES GRUIFORMES (A VES) DES PHOSPHORITES DU QUERCY (FRANCE). 1. SOUS-ORDRE CARIAMAE (CARIAMIDAE ET PHORUSRHACIDAE). SYSTÉMATIQUE ET BIOSTRATIGRAPHIE.
- Mayr, G.; Noriega, J. (2013). "A well-preserved partial skeleton of the poorly known early Miocene seriema Noriegavis santacrucensis (Aves, Cariamidae)". Acta Palaeontologica Polonica. doi:10.4202/app.00011.2013.
- Mayr, G.; Alvarenga, H.; Clarke, J. (2011). "An Elaphrocnemus−like landbird and other avian remains from the late Paleocene of Brazil". Acta Palaeontologica Polonica. 56 (4): 679–684. doi:10.4202/app.2010.0099.
- Gerald Mayr & Cécile Mourer-Chauviré, The peculiar scapula of the late Eocene Elaphrocnemus phasianus Milne-Edwards, 1892 (Aves, Cariamae), December 2008, Volume 88, Issue 2, pp 195-198
- Mayr, Gerald; Alvarenga, Herculano; Clarke, Julia A. (2011). "An Elaphrocnemus-like landbird and other avian remains from the late Paleocene of Brazil". Acta Palaeontologica Polonica. 56 (4): 679–684. doi:10.4202/app.2010.0099.