Coniopternium

Coniopternium is an extinct genus of macraucheniids from the Late Oligocene of South America. Fossils of Coniopternium have been found in the Agua de la Piedra, Deseado, and Sarmiento Formations of Argentina,^[1][2] the Salla Formation of Bolivia,^[3] and the Moquegua Formation of Peru.^[4]

Coniopternium Temporal range: Late Oligocene (Deseadan) ~29.0–23.0 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Astragali of Coniopternium andinum
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	†Litopterna
Family:	†Macraucheniidae
Subfamily:	†Cramaucheniinae
Genus:	†Coniopternium Ameghino, 1894
Type species
†Coniopternium andinum Ameghino, 1894
Species
†C. andinum Ameghino, 1894 †C. primitivum Cifelli and Soria, 1983
Synonyms
†Notodiaphorus crassus Loomis, 1914

Taxonomy

Coniopternium was first described by Ameghino in 1895 based on fossils found in the Sarmiento Formation of Chubut Province, Argentina. 19 years later, in 1914, the species Notodiaphorus crassus had been described, whose fossils were discovered in the La Flecha locality of the Deseado Formation in Santa Cruz Province.^[5] However, later authorities have since synonymized Notodiaphorus with Coniopternium andinum.^[6]