''Nilssonia'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

softshell turtle The Trionychidae are a taxonomic family of a number of turtle genera, commonly known as softshell turtles. The family was erected by Leopold Fitzinger in 1826. Softshells include some of the world's largest freshwater turtles, though many can ad ...

s (

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Trionychidae) from rivers, streams, ponds, and lakes in

South Asia South Asia is the southern subregion of Asia, which is defined in both geographical and ethno-cultural terms. The region consists of the countries of Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka.;;;;;;;; ...

and Burma. In many treatments, it is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

, 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 The pleural cavity, pleural space, or interpleural space is the potential space between the pleurae of the pleural sac that surrounds each lung. A small amount of serous pleural fluid is maintained in the pleural cavity to enable lubrication bet ...

scale pair of the bony

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

, which are fused into one in ''N. formosa'' and unfused in the others. (2007). "Genetic evidence for wild-living ''Aspideretes nigricans'' and a molecular phylogeny of South Asian softshell turtles (Reptilia: Trionychidae: ''Aspideretes, Nilssonia'')". '' Zool. Scripta'' 36 (4): 301–310. (HTML abstract) 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 The Indian softshell turtle (''Nilssonia gangetica''), or Ganges softshell turtle is a species of softshell turtle found in South Asia in rivers such as the Ganges, Indus and Mahanadi. This vulnerable turtle reaches a carapace length of up to . ...

(''A./N. gangeticus'') and the

Leith's softshell turtle Leith's softshell turtle (''Nilssonia leithii'') is a species of turtle in the family Trionychidae. The species is found in peninsular Indian rivers including the Bhavani, Godavari, and Moyariii Rivers. The types.... locality is Pune in India. ...

(''A./N. leithii''), making the merging of the genera well warranted.

Etymology

The generic name, ''Nilssonia'', is in honor of Swedish zoologist Sven Nilsson.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. xiii + 296 pp. . ("Nilsson", p. 191).

Species

If the genera are united, the five species are: *'' Nilssonia formosa'' – Burmese peacock softshell, Burmese softshell turtle *''

Nilssonia gangetica The Indian softshell turtle (''Nilssonia gangetica''), or Ganges softshell turtle is a species of softshell turtle found in South Asia in rivers such as the Ganges, Indus and Mahanadi. This vulnerable turtle reaches a carapace length of up to ...

'' – Indian softshell turtle, Ganges softshell turtle *'' Nilssonia hurum'' – Indian peacock softshell turtle *''

Nilssonia leithii Leith's softshell turtle (''Nilssonia leithii'') is a species of turtle in the family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriag ...

'' – Leith's softshell turtle, Nagpur softshell turtle *''

Nilssonia nigricans The black softshell turtle or Bostami turtle (''Nilssonia nigricans''), previously placed in genus ''Aspideretes'', is a species of freshwater turtle found in India (Assam and Tripura) and Bangladesh (Chittagong and Sylhet District, Sylhet). It ...

'' – black softshell turtle, Bostami turtle

References

{{DEFAULTSORT:Nilssonia (Animal) Turtle genera Taxa named by John Edward Gray Taxonomy articles created by Polbot