Genus Eucholoeops Ameghino, 1887

TYPE SPECIES. — Eucholoeops ingens Ameghino, 1887 .

DIAGNOSIS. — Much smaller than the Plio-Pleistocene grounds sloths but larger than Holocene and extant tree sloths; shares with other megalonychids large C1 and c1, prominent diastema, anteriorly divergent tooth rows, with caniniforms displaced laterally to remaining teeth, and oval to rectangular molariforms; muzzle prominent, short and broad, but less so than in Ahytherium and Megistonyx; differing from Megalonyx in possessing caniniforms that are triangular in section and a longer mandibular spout; differing from other megalonychids with triangular caniniforms (e.g., Choloepus, Acratocnus Anthony, 1916, Neocnus Arredondo, 1961) in having dorsoventrally deep, rather than anteriorly tapered, rostrum; differing from other megalonychids in possessing transversely expanded M2 and M3; width across buccinator fossae much less than width at preorbital rostrum; preorbital rostrum width greater than that of postorbital constriction; posterior surface of lacrimal markedly concave.

DISTRIBUTION. — Santacrucian SALMA (late Early Miocene), Santa Cruz Province, Argentine Patagonia .