Proechimys decumanus Thomas 1899
Proechimys decumanus Thomas 1899, Ann. Mag. Nat. Hist., ser. 7, 4: 282.
Type Locality: Ecuador, Prov. de Guayas, Changón.
Vernacular Names: Pacific Spiny-rat.
Distribution: NW Peru, SW Ecuador, Pacific lowlands.
Conservation: IUCN – Lower Risk (lc).
Discussion: Placed in brevicauda group by Gardner and Emmons (1984), but Patton (1987) recognized it as the sole representative of a decumanus group. Listed as a subspecies of guyannensis by Cabrera (1961), but as a species by Emmons and Feer (1990, 1997). Karyotype has 2n=30 and FN=54 (Gardner and Emmons, 1984).