Cuatro Cienegas softshell
The Cuatro Ciénegas softshell, also called the black spiny softshell, is a subspecies of the spiny softshell turtle in the family Trionychidae. The subspecies, along with its parent species, was formerly classified in the genus Trionyx.A. s. atra is found only in the Cuatro Ciénegas Basin in the state of Coahuila, Mexico.As of the last assessment in 1996, A. s. atra was considered "Critically Endangered" by the "IUCN Red List of Threatened Species".
