''Cochilius'' is an extinct genus of interatheriid notoungulate that lived between the Late

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

and the lower Miocene in what is now Argentina.

Description

The skull and skeleton show features also found in other similar contemporary or slightly later animals, such as ''

Interatherium ''Interatherium'' is an extinct genus of interatheriid mammal from the Early to Middle Miocene (Colhuehuapian- Mayoan). Fossils have been found in the Santa Cruz, Collón Curá and Sarmiento Formations in Argentina.Fernández, M. (2015). Re ...

'' and ''

Protypotherium ''Protypotherium'' is an extinct genus of notoungulate mammals native to South America during the Oligocene and Miocene epochs. A number of closely related animals date back further, to the Eocene. Fossils of ''Protypotherium'' have been found in ...

''. In the general proportions of the skull ''Cochilius'' was similar to ''

'', but in some features it was closer to ''

'', for example, in the large development of the snout and the median position of the orbits. The epitympanic ''sinus'' was slightly spongy. The forelimbs resembled those of ''Interatherium,'' and were more puny than those of ''Protypotherium.'' The metacarpal bones were longer and thinner than those of Interatherium. The incisors were short and strong, while the molars had low-crowned ( brachydont) teeth.

Classification

The genus ''Cochilius'' was first described in

1902 Events January * January 1 ** The Nurses Registration Act 1901 comes into effect in New Zealand, making it the first country in the world to require state registration of nurses. On January 10, Ellen Dougherty becomes the world's f ...

by Florentino Ameghino, based on fossil remains found in Lower Miocene soils in Argentina. The type species is ''Cochilius volvens'', but Ameghino described other species: ''C. columnifer and C. pendens'', also from the Lower Miocene of Argentina. Later, George Gaylord Simpson described the species ''C. fumensis'' from Cerro del Humo in Chubut Province, Argentina from slightly older deposits dating to the Late Oligocene. ''Cochilius'' belongs to the

Typotheria Typotheria is a suborder of the extinct mammalian order Notoungulata and includes five families: Archaeopithecidae, Campanorcidae, Interatheriidae, Mesotheriidae, and Oldfieldthomasiidae. CifelliCifelli, Richard L. 1993. The phylogeny of the nat ...

, a group of notoungulate mammals that evolved during the Eocene in South America, going on to occupy various ecological niches that in the rest of the world were mainly occupied by rodents. ''Cochilius'' was a rather derived member of the family

Interatheriidae Interatheriidae is an extinct family of notoungulate mammals from South America. Interatheriids are known from the Middle Eocene (Mustersan) to the Early Pliocene (Montehermosan).McKenna & Bell, 1997Linares, 2004 These animals were principally sm ...

, within the subfamily

Interatheriinae Interatheriinae is an extinct subfamily of interatheriids that consisted of notoungulates dating from the Early Eocene (Casamayoran SALMA) to the Early Pliocene (Montehermosan SALMA). The subfamily includes the genera '' Archaeophylus'', '' Argy ...

References

{{Taxonbar, from=Q60977262 Typotheres Miocene mammals of South America Oligocene mammals of South America Paleogene Argentina Neogene Argentina Fossils of Argentina Deseadan Colhuehuapian Santacrucian Taxa named by Florentino Ameghino Fossil taxa described in 1902 Prehistoric placental genera Chichinales Formation Golfo San Jorge Basin Sarmiento Formation Austral or Magallanes Basin Santa Cruz Formation