New species of arboreal rat of the genus Rhipidomys (Cricetidae, Sigmodontinae) from Sangay National Park, Ecuador

Researchers have identified a new species of arboreal rat, belonging to the genus Rhipidomys, within Sangay National Park, Ecuador. This discovery was made through a comprehensive analysis combining cranial and external morphology, morphometrics, and phylogenetic studies based on the cytochrome b gene. The new species is distinguished by its relatively small body size (average head–body length 123 mm) and unique cranial features, such as a constricted interorbital region, a barely perceptible postorbital crest in females, and a wide, round braincase. It also exhibits distinctive dental characteristics, including a large and deep hypoflexid on the third molar (m3). This species is currently known only from the southeastern portion of Sangay National Park, suggesting it may be endemic to the Cordillera Oriental of Ecuador. The study further provides insights into its natural history, reproductive behavior, vocalizations, habitat preferences, and phylogenetic placement.

Brito, J. M., Tinoco, N., Chávez, D., Moreno-Cárdenas, P., Batallas, D., & Ojala-Barbour, R. (2017). New species of arboreal rat of the genus Rhipidomys (Cricetidae, Sigmodontinae) from Sangay National Park, Ecuador. Neotropical Biodiversity, 3(1), 65–79. https://doi.org/10.1080/23766808.2017.1292755