Neacomys Thomas, 1900

Voss, Robert S., Fleck, David W. & Jansa, Sharon A., 2019, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 5. Rodents, Bulletin of the American Museum of Natural History 2024 (466), pp. 1-180 : 51

Neacomys Thomas, 1900

Species of Neacomys (commonly known as spiny mice) are small cricetids with spiny, reddish-brown dorsal pelage; self-whitish or -buffy underparts; eight mammae; and tails that are about as long as the combined length of head and body. Skulls of Neacomys have beaded and anteriorly convergent supraorbital margins; long, narrow, subparallel incisive foramina; and sphenopalatine vacuities in the roof of the mesopterygoid fossa. The carotid circulation is either pattern 1 or pattern 2 ( Voss, 1988), the upper incisors are strongly opisthodont, and the capsular process of the lower incisor alveolus is well developed. Species of Scolomys —the only other spiny cricetids in western Amazonia—are easily distinguished from Neacomys by conspicuous external and craniodental differences (table 14). Neacomys has been the focus of much recent systematic research (e.g., Hurtado and Pacheco, 2017; Sánchez-Vendizú et al., 2018; Semedo et al., 2020, 2021; Brito et al., 2021), with results that have substantially revised the species-level taxonomy previously summarized by Weksler and Bonvicino (2015a). Specimens that we examined from the Yavarí-Ucayali interfluvium can be assigned to two species, but a third can also be expected to occur in our region (appendix 2).

Capture data summarized below is consistent with previously reported trapping results from other Amazonian research sites (e.g., Patton et al., 2000; Voss et al., 2001; Hice and Velazco, 2012) in suggesting that species of Neacomys are almost exclusively terrestrial.