Apalone spinifera atra (Family Trionychidae), endemic to the Cuatrociénegas Basin of Coahuila, Mexico, is an enigmatic and severely threatened softshell turtle. On the basis of morphology, it has been regarded as a full species (Apalone ater), but by phylogenetic molecular analyses it is currently considered a subspecies of A. spinifera. The discovery of color morphs correlated to substrate coloration in different localities and the recognition of hybridization between A. s. atra and A. s. emoryi have led to additional taxonomic uncertainty. In addition, A. s. atra has a very restricted distribution with an apparently small population size that is also being affected by genetic introgression from A. s. emoryi. These factors, combined with recent anthropogenic draining and alteration of its limited freshwater habitats, have placed A. s. atra at very high risk for extinction in the near future, if careful conservation actions are not taken immediately. In addition, a lack of information about its ecology has made its relationships and survival prospects more difficult to discern. It is listed as Critically Endangered by the IUCN Red List, included on Appendix I of CITES, listed as Endangered by US ESA, and as a Species of Special Concern by the Mexican Secretaría de Medio Ambiente y Recursos Naturales. distribution. -Mexico. Restricted to the Cuatrociénegas Basin, Coahuila.