Type of Shell: Hard shell with dorsal keels

Common Map turtles are found in the eastern Midwest states, small patches in the Northeastern states, and south to Arkansas and northern Alabama. This species is not strictly found in rivers, they also inhabit lakes and other large bodies of water. They prefer slow currents, logs of aquatic plants and soft substrate.

Reverse sexual dimorphism is shown in this genus; adult females around 11 inches and adult males are around half that size. Adult females also tend to have more rounder shells and broader heads.

Breeding starts early to mid summer. Around 6 to 20 eggs are laid, often in several clutches, in late summer. If hatching is late in the year, the baby turtles will overwinter in the nest and emerge the following spring. According to a paper titled: Adaptations to terrestrial overwintering in map turtles, Graptemys geographica, Common map turtles lack the freeze tolerance that Painted Turtles and Box turtles have, but instead of freezing they "exploit a strategy of freeze avoidance, via supercooling" (Baker, Costanzo, Iverson, Lee 2003).

Like many other members in this genus, the Common Map Turtles feeds mainly on freswater mollusks, but insects and crustaceans are also eaten.

The genus name of this species means a turtle that is written on. The the species name means map. This is because many map turtles have shell patterns that resemble topological maps.

References