Tate's fat-tailed mouse opossum (Thylamys tatei) is a species of opossum in the family Didelphidae,[2] named after American zoologist George Henry Hamilton Tate.[3] It is found at elevations of 300 to 3,000 m along the coast of central Peru.[1] The species has the northernmost range of any member of its genus.[1] It has white ventral fur and short condylobasal and zygomatic lengths. T. pallidior is very similar.[4]