Mesomys stimulax Thomas 1911

Wilson, Don E. & Reeder, DeeAnn, 2005, Order Rodentia - Family Echimyidae, Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 2, Baltimore: The Johns Hopkins University Press, pp. 1575-1592 : 1584

Mesomys stimulax Thomas 1911

Mesomys stimulax Thomas 1911 , Ann. Mag. Nat. Hist., ser. 8, 7: 607.

Type Locality: Brazil, Pará, Amazon estuary, "Cametá, Lower Tocantins." .

Vernacular Names: Para Spiny Tree Rat.

Distribution: Brazil, east of the Rio Tapajós and south of the Amazon.

Conservation: IUCN – Lower Risk (lc).

Discussion: Formerly included in hispidus by Cabrera (1961); considered a distinct species by Husson (1978). Material from south of the Amazon and east of the Rio Tapajós in Brazil is karyotypically identical (2n=60, FN=116) with hispidus ( Patton et al., 2000) but genetically divergent ( da Silva and Patton, 1993; Patton et al., 2000). Voss et al. (2001) examined the holotype and grouped it with "small-toothed" forms from Guiana and SE Amazonia. Small-toothed forms from NE South America, however, have affinities with hispidus , whereas stimulax appears to be restricted to areas east of the Rio Tapajós and south ofthe Amazon ( Orlando et al., 2003; Patton et al., 2000).