Brophy (2004) recently completed a detailed study of geographic
variation in turtles from the genus Malayemys and
argued for the existence of two distinct species: M. subtrijuga
(Schlegel and Müller, 1844) from the Mekong River Basin of
eastern Thailand, Laos, Cambodia, and southern Vietnam; and
M. macrocephala (Gray, 1859) from the Chao Phraya and Mae
Klong basins of central Thailand, the coastal areas of southeastern
Thailand and Cambodia, and the Malay Peninsula in southern
Thailand and northern Malaysia.