The species Sternotherus carinatus was described by British Zoologist John Edward Gray in 1855. The common name of Sternotherus carinatus is Razorback musk turtle.

The Sternotherus carinatus is the biggest turtle of the genus Sternotherus, but still relatively small as you compare it with some other Freshwater turtle species.. It varies from 12 till 17cm. Females stay smaller with a maximum SCL of 14cm, while males are most of the time larger.

The carapax shows a strong vertebral keel, that can be confused with the keels of Sternotherus minor minor when they are small, but with Sternotherus carinatus, you have a more steep keel, and only one keel, whil with Sternotherus minor minor you have three keels. Another difference is that the Sternotherus carinatus is possessing only 10 scutes, while the other species of the genus Sternotherus show 11 scutes. The razorback turtle lacks a gular scute.
The plastron is yellow, to light brown, the chin has 2 barbels, the snout is a bit tubular, and the feet are webbed.

 

The difference between adult males and females is remarkably. Females have a short, small tail and no rough hind limb scale patches.
Males have a big tail that end in a blunt terminal nail. They have two patches of scales on the inner surface of each leg.