A species of turtle native to the brackish coastal swamps of the eastern and southern United States. The common name refers to the diamond pattern on top of its shell (carapace), but the overall pattern and coloration vary greatly. The shell is usually wider at the back than in the front and from above its appears wedge shaped. Its shell coloring can vary from browns to greys, and its body color can be grey, brown, yellow, or white. All have a unique pattern of wiggly, black markings or spots on their body and head. The diamondback terrapin have large webbed feet. The species is sexually dimorphic in that the males grow to approximately 5.1 inches, while the females grow to an average of around 7.5 inches, though they are capable of growing larger.
Found near salt water coastal areas. They can survive in freshwater as well as full strength ocean water but adults prefer intermediate salinities.