Hydromedusa
Hydromedusa is a turtle genus in the family Chelidae, commonly known as the South American snake-necked turtles. They are quite closely related to the South American side-necked swamp turtles ("Acanthochelys") and the snake-necked turtles of the Australian-Melanesian region ("Chelodina"), but less closely to the spine-necked river turtles of South America ("Podocnemididae") which belong to a more modern lineage of Pleurodira. Species. This genus contains the following extant and fossil species: