Sigmodontomys aphrastus Harris 1932
Sigmodontomys aphrastus Harris 1932, Occas. Pap. Mus . Zool., Univ. Michigan, 248: 5.
Type Locality: Costa Rica, San José Prov., San Joaquin de Dota, 4000 ft (1219 m).
Vernacular Names: Long-tailed Sigmodontomys.
Distribution: Known only from the type locality, Chiriqui Prov. in W Panamá, and Pichincha Prov. in NC Ecuador (Voss, 1988:423).
Conservation: IUCN – Critically Endangered.
Discussion: Usually listed as a species of Oryzomys of uncertain relationship (Hall, 1981). Assignment to Sigmodontomys tentative following the observations of Ray (1962). Distribution meagerly documented, known by only four specimens.