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Cochilius

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Cochilius
Temporal range: Late Oligocene-Early Miocene (Deseadan-Santacrucian)
~29.0–16.3 Ma
Skull of Cochilius volvens
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Notoungulata
Family: Interatheriidae
Subfamily: Interatheriinae
Genus: Cochilius
Ameghino, 1902
Type species
Cochilius volvens
Ameghino, 1902
Other species
  • C. brevirostris Bordas, 1939
  • C. columnifer Ameghino, 1902
  • C. fumensis Simpson, 1932
  • C. minor Bordas, 1939
  • C. pendens Ameghino, 1902

Cochilius is an extinct genus of interatheriid notoungulate that lived between the Late Oligocene and the lower Miocene in what is now Argentina.

Description

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The skull and skeleton show features also found in other similar contemporary or slightly later animals, such as Interatherium and Protypotherium. In the general proportions of the skull Cochilius was similar to Interatherium, but in some features it was closer to Protypotherium, 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 were low-crowned (brachydont) teeth.[1]

Classification

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The genus Cochilius was first described in 1902 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.[2] 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.[3][4]

Cochilius belongs to the Typotheria, 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.[5] Cochilius was a rather derived member of the family Interatheriidae, within the subfamily Interatheriinae.[1]

References

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  1. ^ a b Vera, Bárbara; Cerdeño, Esperanza; Reguero, Marcelo (2017-07-04). "The Interatheriinae from the Late Oligocene of Mendoza (Argentina), with comments on some Deseadan Interatheriidae". Historical Biology. 29 (5): 607–626. Bibcode:2017HBio...29..607V. doi:10.1080/08912963.2016.1220945. hdl:11336/49742. ISSN 0891-2963. S2CID 88869146.
  2. ^ Ameghino, Florentino (1902). "Première contribution a la connaissance de la faune mammalogique des couches a Colpodon". Boletin de la Academia Nacional de Ciencias en Córdoba, República Argentina. 17: 71–141. ISSN 0325-2051.
  3. ^ Expedition (1930-1931); Simpson, George Gaylord. "New or little-known ungulates from the Pyrotherium and Colpodon beds of Patagonia". American Museum Novitates (576).{{cite journal}}: CS1 maint: numeric names: authors list (link)
  4. ^ Simpson, George Gaylord. "Cochilius volvens from the Colpodon beds of Patagonia". American Museum Novitates (577).
  5. ^ Goin, Francisco J.; Abello, María Alejandra (February 2013). "Los Metatheria Sudamericanos de Comienzos Del Neógeno (Mioceno Temprano, Edad MamÍFero Colhuehuapense): Microbiotheria y Polydolopimorphia" (PDF). Ameghiniana. 50 (1): 51–78. doi:10.5710/AMGH.9.11.2012.570. ISSN 0002-7014.