The spiny softshell turtle is a species of softshell turtle, one of the largest freshwater turtle species in North America. Both the common name, spiny softshell, and the specific name, spinifera (spine-bearing), refer to the spiny, cone-like projections on the leading edge of the carapace, which are not scutes (scales).
Spiny softshell turtle
A spiny softshell turtle laying eggs at Los Angeles' Baldwin Lake, a part of the species' non-native introduced range
Juvenile spiny softshell turtles
Image: Eastern Spiny Softshell Turtle (Apalone spinifera spinifera) Flickr 2nd Peter
The Trionychidae are a taxonomic family of a number of turtle genera, commonly known as softshell turtles. The family was erected by Leopold Fitzinger in 1826. Softshells include some of the world's largest freshwater turtles, though many can adapt to living in highly brackish areas. Members of this family occur in Africa, Asia, and North America, with extinct species known from Australia. Most species have traditionally been included in the genus Trionyx, but the vast majority have since been moved to other genera. Among these are the North American Apalone softshells that were placed in Trionyx until 1987.
Trionychidae
Head and neck of Pelodiscus sinensis
Japanese suppon-nabe made from softshell turtle
Fossil of Plastomenus sp. in the Field Museum of Natural History, Chicago