Saimiri ustus I. Geoffroy 1843
Saimiri ustus I. Geoffroy 1843, C. R. Acad. Sci. Paris, 16 (21): 1157.
Type Locality: Brazil, Amazonas, Rio Madeira, Humaitu.
Vernacular Names: Bare-eared Squirrel Monkey.
Synonyms: Saimiri madeirae Thomas 1908 .
Distribution: S Brazil: south of Rio Amazon, probably from Rio Xingu to Lage Tefé, approx. 61°30’W.
Conservation: CITES – Appendix II; IUCN – Least Concern.
Discussion: S. sciureus species group. Thorington (1985) and Costello et al. (1993) argued that ustus is a synonym of S. sciureus (so that the correct name should be madeirae), but this is not the case (Groves, 2001 c:159). Costello et al. (1993) regarded this species as not specifically distinct from S. sciureus .