The ''Myuchelys'' 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 ...

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked tu ...

s, the Australian saw-shelled turtles, 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 marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Chelidae Chelidae is one of three living families of the turtle suborder Pleurodira, and are commonly called Austro-South American side-neck turtles. The family is distributed in Australia, New Guinea, parts of Indonesia, and throughout most of South Amer ...

and subfamily Chelodininae. They inhabit the headwaters and tributaries of rivers within their range and this led to the name ''Myuchelys'', which is formed from the Aboriginal word ''myuna'' meaning clear water and the Greek ''chelys'' meaning turtle. They have a short neck and the intergular scute completely separates the gular scutes. They have no

alveolar ridge The alveolar process () or alveolar bone is the thickened ridge of bone that contains the tooth sockets on the jaw bones (in humans, the maxilla and the mandible). The structures are covered by gums as part of the oral cavity. The synonymous ter ...

separating them from the snapping turtles of the

Elseya ''Elseya'' is a genus of large side-necked turtles, commonly known as Australian snapping turtles, in the family Chelidae. Species in the genus ''Elseya'' are found in river systems in northern and northeastern Australia and throughout the river ...

''.

Species

The genus currently contains these cryptic small

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of freshwater turtles, endemic to eastern and northern Australia: * '' Myuchelys bellii'', Namoi River snapping turtle Gray, 1844Gray, J. E. 1844. ''Catalogue of the Tortoises, Crocodiles and Amphibaenians in the Collection of the British Museum''. London. Edward Newman. 80pp. * '' Myuchelys georgesi'', Bellinger River snapping turtle Cann, 1997Cann, J. 1998a. Georges short-neck turtle. ''Monitor'' 9(1):18-23. * ''

Myuchelys latisternum The saw-shelled turtle (''Myuchelys latisternum'') is a species of turtle in the Chelidae family endemic to Australia, ranging along rivers and streams and connected swamps and lagoons from coastal Cape York Peninsula to northern New South Wales ...

'', saw-shelled turtle Gray, 1867 * '' Myuchelys purvisi'', Manning River snapping turtle

Taxonomic history

The species ''Myuchelys latisternum'' was originally placed in the genus ''Elseya'' by Gray in 1867 but ''Elseya'' was redefined by

George Albert Boulenger George Albert Boulenger (19 October 1858 – 23 November 1937) was a Belgian-British zoologist who described and gave scientific names to over 2,000 new animal species, chiefly fish, reptiles, and amphibians. Boulenger was also an active botani ...

in 1889 to include species defined by the presence of an alveolar ridge. Hence, ''Myuchelys latisternum'' and '' Myuchelys novaeguineae'' were moved to the genus ''

Emydura ''Emydura'', the Australian short-necked turtles, are a genus of turtles in the family Chelidae. It was paraphyletic with ''Elseya''. Consequently, it was split into two genera '' Myuchelys'' and ''Elseya'' by Thomson & Georges, 2009.Thomson, ...

''. In 1967, the two species were placed back in the genus ''Elseya'' by J. Goode,Goode, J. (1967) Freshwater Tortoises of Australia and New Guinea (in the Family Chelidae). Lansdowne Press, Melbourne. where they remained until recently. During the time, the species ''Myuchelys bellii'' was basically lost to knowledge, having been misidentified as a South American species when described by Gray in 1844, and was in the genus ''

Phrynops Sometimes called the bearded toadheads but better known by their scientific name of ''Phrynops'' this genus of turtles has often been a bit of a dumping ground for the short-necked South American turtles of the family Chelidae. The genus is wide ...

'' until this oversight was corrected by Cann in 1998.Cann, J. (1998) Australian Freshwater Turtles. Beaumont Publishing, Singapore. The species ''Myuchelys georgesi'' and ''Myuchelys purvisi'' were initially placed in the genus ''Elseya'', but were identified as belonging to a unique clade along with ''Myuchelys latisternum'' and ''Myuchelys bellii'' using

electrophoresis Electrophoresis, from Ancient Greek ἤλεκτρον (ḗlektron, "amber") and φόρησις (phórēsis, "the act of bearing"), is the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric fie ...

. The first attempt to separate this group into its own genus was the genus ''Euchelymys'' (Gray, 1871), but this name was subsequently synonymised with ''Elseya'' by Boulenger (1889) and the name was made permanently unavailable when Lindholm (1929)Lindholm, W.A. (1929) Revidiertes Verzeichnis der Gattungen der rezenten Schildkröten nebst Notizen zur Nomenklatur einger Arten. Zoologischer Anzeiger, 81, 275–295. set ''Euchelymys sulcifera'' (= ''Emydura macquarii'') as the type species, effectively making the name ''Euchelymys'' a junior synonym of ''Emydura''. Another option investigated was the fossil form ''Pelocomastes'', de Vis 1897;de Vis, C.W. 1897. The extinct freshwater turtles of Queensland. Annals of the Queensland Museum. 3: 3-7. the species in this genus may have represented an extinct member of the ''latisternum'' group, but this was determined to be incorrect and the name ''Pelocomastes'' is now considered a junior synonym of ''Elseya''.Thomson, S. A. 2000 06 30: A Revision of the Fossil Chelid Turtles (Pleurodira) Described by C.W. De Vis, 1897. Memoires of the Queensland Museum 45(2):593-598. Brisbane. . The genus name ''Wollumbinia'' was erected by Wells, 2007,Wells, R.W. (2007
Some taxonomic and nomenclatural considerations on the Class Reptilia in Australia. A new genus of the Family Chelidae from eastern Australia.
"Australian Biodiversity Record", 2007(3), 1–12. however, this paper was declared to be in breach of the ICZN code defining a valid publication, ICZN Articles 8 and 9 and Recommendation 8D.Fritz, U. & Havaš, P. (2007
Checklist of Chelonians of the World.
Vertebrate Zoology (Dresden), 57, 149–368. As such this name is not considered valid. The genus encompassing these species was named ''Myuchelys'' by Thomson and Georges, 2009. Currently, this arrangement is considered the accepted name for the ''latisternum'' group by the IUCN, multiple taxonomic checklists and by numerous workers in diverse disciplines. In the ensuing time the name ''Myuchelys'' has established usage as defined by the ICZN code, with many research papers using it and almost none using alternatives. It is therefore unlikely to be replaced and would require a decision of the ICZN now to do so. In 2013, Le ''et al''. found that one species, ''purvisi'', was still paraphyletic and proposed a new monophyletic genus to handle this; ''purvisi'' was therefore moved to the genus ''Flaviemys''. In 2017, the IUCN TTWG following the recommendation of Spinks et al. (2015) placed ''Flaviemys'' as a synonymy of Myuchelys.

References

{{Taxonbar, from=Q2437317 Turtle genera Turtles of Australia Taxa named by Scott A. Thomson