Location:my freshwater garden area The Trionychidae are a taxonomic family of a number of turtle genera, commonly known as softshell turtles. The family was founded by Leopold Fitzinger in 1826. Softshells include some of the largest freshwater turtles in the world, although many are able to adapt to living in very brackish areas. These family members occur in Africa, Asia, and North America. A large number of species are traditionally included in the genus Trionyx.