1-5, see text
Nilssonia is a genus of softshell turtles (family Trionychidae) from rivers, streams, ponds, and lakes in South Asia and Burma. In many treatments, it is monotypic, with the single species Burmese peacock softshell (N. formosa). However, the supposed other genus of peacock softshells, Aspideretes, is more closely related to N. formosa than had been believed. They differ only in the neural plates between the first pleural scale pair of the bony carapace, which are fused into one in N. formosa and unfused in the others.
Thus, it has been proposed to unite the two genera under the older name, Nilssonia. As it seems, the closest living relatives of the Burmese peacock softshell are the Indian softshell turtle (A./N. gangeticus) and the Leith's softshell turtle (A./N. leithii), making the merging of the genera well warranted.
The generic name, Nilssonia, is in honor of Swedish zoologist Sven Nilsson.
If the genera are united, the five species are:
Nota bene: A binomial authority in parentheses indicates that the species was originally described in a genus other than Nilssonia.