Hylaeamys yunganus (Thomas, 1902)

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 : 50

Hylaeamys yunganus (Thomas, 1902)

Figures 19C, 19F

VOUCHER MATERIAL (N = 12): El Chino (UF 30540–30542), Nuevo San Juan (MUSM 11221, 13332), San Pedro (UF 30483, 30503, 30526, 30528, 30535, 30543, 30545). Additional material that we have not seen was reported by Pavlinov (1994) from Jenaro Herrera.

UNVOUCHERED OBSERVATIONS: None.

IDENTIFICATION: Hylaeamys yunganus (formerly Oryzomys yunganus ; Weksler et al., 2006) is another widespread species; as currently recognized, it ranges throughout Amazonia from the Atlantic coast to the base of the Andes ( Musser et al., 1998; Percequillo, 2015b). As noted by Musser et al. (1998) and Voss et al. (2001), this species exhibits substantial geographic variation in size, with eastern Amazonian specimens averaging smaller than western Amazonian specimens in most external and craniodental dimensions. Crown length of the molar toothrow (LM), for example, is 4.4 ± 0.1 mm in a series from French Guiana (Voss et al., 2001: table 34) versus 4.8 ± 0.1 mm in our series from the Yavarí-Ucayali interfluve (table 11). Nevertheless, other (size-independent) morphological differences between eastern and western Amazonian populations are not apparent, nor do eastern and western Amazonian cytochrome b sequences form reciprocally monophyletic haplogroups ( Patton et al., 2000: fig. 97), so there is currently no compelling evidence for recognizing additional taxa in the Yunganus Group (sensu Musser et al., 1998).