Wagler, 1830
South American side-necked turtles
Recognition
This pleurodiran genus comprises six neotropical riverine turtles. The oval carapace is flattened or slightly domed and with or without a middorsal keel in adults. There are six or seven neural bones well-separated from the suprapygal bone, but in contact with the nuchal. The large plastron is rigid, without a hinge, and has a pair of small, lateral mesoplastral bones lying between the hyo- and hypoplastra. Its axillary and inguinal buttresses are large and well-developed. No cervical scute is present. The skull is elongated and in some cases broad, with a well-developed dermal roof which is slightly emarginated posteriorly. The postorbital bone is very small and well-separated from the quadratojugal and squamosal bones. The quadratojugal lies between the quadrate and jugal bones and prevents their contact. The quadratojugal touches the parietal bone. The parietal also has anterolateral contact with the jugal. A small vomer may be present. One, two, or three ridges occur on the triturating surface of the maxilla, and the upper jaw is either medially notched, rounded, or squared off. There is a single, large scale between the orbits, and an interorbital groove may be present. One to three chin barbels are present. The toes are webbed.
Species identification
Species are compared in Chars. of Podocnemis adults, or jump to the key: Page 28: Genus Podocnemis