Graptemys - derived from two Greek words, grapto meaning inscribed or painted, and emydos, a freshwater turtle
geographica - given for the markings on the carapace which resemble contour lines on a map
The common name is derived from the map-like patterns on its carapace and skin. Map turtles are known for their communal basking; the turtles gather on rocks and logs jutting out from deep water, and bask together. Often, when space is short, one turtle crawls on top of another. This group basking may help the turtles keep watch for potential predators; when one individual becomes alerted, for example by seeing a human, the entire group scrambles for safety.