A new species of Andean mouse of the genus Thomasomys (Cricetidae, Sigmodontinae) from the eastern Andes of Ecuador

We name and describe a new species of Andean mouse from the eastern slope of the Andes of central Ecuador (Sangay National Park). This rodent is large-bodied (head-body length 167-184 mm) inhabiting the wet montane forest between 3,400-3,900 m in elevation. A molecular phylogeny based on mitochondrial genes resolved the new species as a member of the "aureus" group, closely related to an undescribed species from north Ecuador. This finding increases the diversity of Thomasomys to 48 species, of which 18 species inhabit Ecuador. In addition, the species described herein is the largest species of the genus described in Ecuador.