The Pacific coastal desert of Peru harbors a unique bat fauna, including narrowly endemic taxa adapted to arid environments. This region was also the setting where several pre-Incan civilizations flourished. The Moche culture (100–850 CE) was one of those, with a rich and diverse material culture that included strikingly realistic ceramic representations of the regional flora and fauna. In particular, one Mochica pottery vessel is in the form of a bat that, based on external characteristics (large pinnae and tragus, pinnae connected by high band of membrane across the forehead, and lack of noseleaf), clearly represents an individual of the vespertilionid genus Histiotus. The morphological characteristics observed in this vessel, in addition to the area of influence of the Moche culture, suggests that this vessel depicts a species previously unknown to science that we describe here as new on the basis of two specimens obtained in 2012 in the Peruvian department of Piura. Our new species, Histiotus mochica, can be distinguished from other congeners by having unicolored dorsal fur, medial lobes of pinnae greater than 9.5 mm wide, and a well-developed (>4.3 mm high) transverse band of skin connecting the pinnae. Cytochrome b sequence data indicate that the new species is sister to H. humboldti from the Andes of Colombia and northern Ecuador. The new species is a medium-sized Histiotus that clusters with H. laephotis, H. velatus, and with small specimens of H. montanus in our multivariate analyses. With the description of H. mochica, the diversity of the genus increases to 11 species. We provide a key based on external characters of all known species of Histiotus.