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 Formation|Agua de la Piedra], Deseado, and Sarmiento Formations of Argentina,
the Salla Formation
of Bolivia,
and the Moquegua Formation of Peru.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, Argentina|Santa Cruz Province]. However, later authorities have since synonymized Notodiaphorus with Coniopternium andinum.