 Shared features include a lack of inframarginal scutes, the shape and muscle attachment of the ilium, and the shape of the eighth cervical vertebra (biconvex).Within the Emydidae, two subfamilies were recognized along biogeographic lines.The Emydidae as understood today contain New World species (except "Emys"), while the former Batagurinae, today a separate family Geoemydidae, contain Old World species (except "Rhinoclemmys").