''Shecenia'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus of

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

, probably belonging to the order Astrapotheria. It lived between the Late Paleocene and the Early Eocene, and its fossilized remains were found in South America.

Description

This animal is known from very fragmentary remains, including a partial mandible. Its relatives, the astrapotheres, vaguely resembled tapirs. The mandibular symphysis was quite long and flat on the interior surface. it had two pairs of small incisors, framed posteriorly and a bit laterally by a pair of very strong, long-rooted, very curved and forward-protruding teeth. Behind them was a large diastema, followed by another pair of very strong teeth, slightly curved forward but with a short root. These two teeth were approximately located near the middle of the symphysis. Like '' Trigonostylops'', the symphysis of ''Shecenia'' had a flat lower edge.

Classification

''Shecenia'' was first described in 1935 by George Gaylord Simpson, based on fossils found in probably Lower Eocene terrains from Argentina. The type species is ''Shecenia ctirneru'', but other remains from the Late Paleocene have also been attributed to the genus. ''Shecenia'' is considered an archaic astrapothere, a mysterious group of South American mammals, vaguely reminding of tapirs. ''Shecenia'' is considered to be a member of

Trigonostylopidae ''Trigonostylops'' is an extinct genus of South American meridiungulatan ungulate, from the Late Paleocene to Late Eocene (Itaboraian to Tinguirirican in the SALMA classification) of South America (Argentina and Peru) and Antarctica (Seymour Isla ...

, a clade comprising some of the oldest and more archaic members of Astrapotheria.

Bibliography

*G. G. Simpson. 1935. Descriptions of the oldest known South American mammals, from the Rio Chico Formation. American Museum Novitates 793:1-25 *G. G. Simpson. 1967. The beginning of the age of mammals in South America. Part II. Bulletin of the American Museum of Natural History 137:1-260 *M. O. Woodburne, F. J. Goin, M. S. Raigemborn, M. Heizler, J. N. Gelfo and E. V. Oliveira. 2014. Revised timing of the South American early Paleogene land mammal ages. Journal of South American Earth Sciences 54:109-119 {{Taxonbar, from=Q60977964 Meridiungulata Paleocene mammals of South America Eocene mammals of South America Paleogene Argentina Fossils of Argentina Fossil taxa described in 1935 Prehistoric placental genera