508.

Intermediate Lesser Grass Mouse

Microakodontomys transitorius

French: Oryzomys intermédiaire / German: Brasilia-Ratte / Spanish: Ratén de hierba mediano

Other common names: Transitional Colilargo

Taxonomy. Microakodontomys transitorius Hershkovitz, 1993, Parque Nacional de Brasilia, 1100 m, Federal District, Brazil.

Microakodontomys transitorius is the type species of the genus. Monotypic.

Distribution. Known only from the type locality in C Brazil.

Descriptive notes. Head—body 70 mm,tail 93 mm, ear 13 mm, hindfoot 21 mm. No specific data are available for body weight. The Intermediate Lesser Grass Mouse is small—one of the smallest representatives of its subfamily—with long, conspicuously scaled tail that is much longer than head-body length and relatively long and narrow hindfoot. Back pelage is soft and somewhat lax, buffy ocherous, tinged blackish; venter is creamy. Guard hairs on dorsum are black, forming dark dorsal strip compared with fewer, shorter guard hairs on flanks that appear more ocherous. Snout has black band reaching from tip to corner of eye where it forms black eye-ring. Mystacial vibrissae are relatively short, with the longest only extending to ears. Proximal one-half oftail 1s bicolored, and where it is bicolored, hair on dorsal surface is black, whereas hair on ventral surface grades from completely ocherous (proximal portion) to black basally with ocherous tips (distal portion). Tip oftail has slight tuft. First digit is much shorter than the other digits. Claws are thin and moderately long, with sparse pale ungual hairs. Chromosomal complement is 2n = 38, FN = 46.

Habitat. Transitional habitat between wet “campo limpo” (grassland) and “campo sujo” (shrubby grassland) in Cerrado biome.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. The Intermediate Lesser Grass Mouse is terrestrial but probably partially scansorial.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Endangered on The UICN Red List. The Intermediate Lesser Grass Mouse occurs in less than 5000 km? that are severely fragmented. Suitable habitat continues to decline in extent and quality.

Bibliography. Bonvicino, Lazar et al. (2014), Gutiérrez & Marinho-Filho (2017), Hershkovitz (1993), Marinho-Filho & Vieira (2010), Musser & Carleton (2005), Paresque & Hanson (2015).