Kinosternon integrum (Testudines: Kinosternidae): Neotype Designation, Morphology and Distribution

The widespread but endemic mud turtle species Kinosternon integrum Le Conte, 1854 currently ranges throughout most of Mexico, from southern Sonora in the northwest to and through western, central and southern Mexico at least to eastern Oaxaca. Broad and convincing evidence indicates that Kinosternon integrum actually represents a taxonomically complicated species complex; however, as the holotype has allegedly been lost for more than a sesquicentennial and the specimen’s original collection locality data is lacking, a comprehensive systematic revision of the original concept of the species is required before convincing taxonomic subdivision of the complex can proceed. In this contribution we designate a neotype specimen, drawing from the species junior subjective synonym Cinosternon rostellum Bocourt, 1876 and subsequent junior objective synonym Cinosternon guanajuatense Dugès, 1888. We review nomenclatural history and application, argue for the ambit of locality data of the lost holotype collected during the Mexican-American War (1846-1848) and provide a sensu-stricto morphological redescription of, K. integrum based on the museum accessioned and living specimens documented throughout the range. Even though this study now confines its distribution to the majority of states within central Mexico, K. integrum retains its honorific of the most vagile and widely distributed mud turtle in the country.