Subfamilia Deirochelyinae

Gaffney and Meylan, 1988
Deirochelyine turtles

The Chrysemys complex of McDowell (1964). This subfamily has six genera and 30 species, including the freshwater genera Deirochelys, Chrysemys, Graptemys, Pseudemys, and Trachemys, and the brackish water genus Malaclemys. All have a rigid plastron with the humero-pectoral seam crossing posterior to the entoplastron. The triturating surface is usually broad (narrow in Deirochelys), with or without ridges, and with the upper surface containing parts of the palatine or the pterygoid bone (except in Deirochelys) The orbito-nasal foramen is usually much larger than the posterior palatine foramen (but not as large in Deirochelys). The interorbital region is not coarsely sculptured, and the postorbital bar is not wide. Jugals and palatines touch. With the exception of Deirochelys, the cervical vertebrae are not elongated, nor the cervical extensor muscles hypertrophied. Epipubes are not ossified. Musk glands are absent.