The nose tapers to a point and resembles a snorkle. There is a ridge in each nostril. Adult females are much more drab in coloration and the ocelli break up and become large dark blotches on the carapace. The neck and feet are strongly patterned with yellow and black. Their plastron is quite small and white with no distinctive markings.
Males have a long, thick tail with the opening near the tip.
Females have tails so short, that they barely extend past the edge of the carapace and have the opening higher up. The young are about two inches at hatching and are patterned with dark spots or circles like adult males. Their shells are smooth the first few years of life. There are two subspecies reported in Iowa. The western spiny softshell, A. s. hartwegi, is found in most of the Iowa range.