(Uploaded by Plazi for the Bat Literature Project) New distributional mammal records are reported for Yaxchila´n, Chiapas, Mexico, and Belize. Nice´foro's large-eared bat Trinycteris nicefori (Chiroptera, Phyllostomidae) is documented for the first time for Mexico, providing the northwesternmost locality for the species. A new Belizean locality also is reported and constitutes the northernmost record. The dark Mexican shrew Cryptotis griseoventris (Soricomorpha, Soricidae) has been reported previously from the highlands from Chiapas, in coniferous forest at elevations above 2,100 m; its presence in the lowland Selva Lacandona (below 90 m) is surprising and raises questions about its specific identify. Further studies are warranted.