The two species of softshell turtles (spiny and smooth) can easily be distinguished from all other turtles in Oklahoma by the total lack of scutes on the shell. Shells are relatively smooth and leather-like, except that the spiny softshell has distinct spines at the front and back of the shell. Edges of the shell are flexible. Webbing on feet is complete and the snout is long and thin. The smooth softshell lacks small spines at the front of the carapace just behind the neck, and the entire carapace is smooth, which is not the case in the spiny softshell. In addition, careful examination of the nostrils at the tip of the pointed snout reveals circular openings with no ridges projected toward the center.
The North American distribution of smooth softshells is confined for the most part to tributaries of the Mississippi, Missouri, and Ohio rivers. North to south, they occur from southern North Dakota to south-central Texas, and from west to east from the Texas panhandle to Pennsylvania, with an isolated population in northeastern New Mexico.
Smooth softshells are active from late April through mid-October. Male smooth softshells reach sexual maturity in about four years whereas females reach maturity at an age of nine years. Females deposit eggs in shallow nests on sandbars with little vegetation during late May and through June. Number of eggs in a clutch varies from 6-20 or more, averaging about 13. Hatchlings appear in August and September. Smooth softshells are omnivorous, eating fish, crayfish, snails, carrion, and nearly anything they can capture.
Adult females can reach 14 inches in carapace length, but males are much smaller, reaching only about 7 inches. Recently hatched juveniles are about one inch in plastron length.
Species of Greatest Conservation Need