''Chelodina canni'', also known commonly as Cann's snake-necked turtle, is a

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 ...

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 t ...

in the

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

Chelidae. The species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to Australia, where it is found in the northern and northeastern parts of the continent. McCord W, Thomson S (2002). "A new species of ''Chelodina'' (Testudines: Pleurodira: Chelidae) from Northern Australia". ''Journal of Herpetology'' 36 (2): 255-267. It has a narrow zone of hybridization with its related species the eastern snake-necked turtle, '' C. longicollis''. For many years ''C. canni'' was assumed to be the same species as '' C. novaeguineae'' from

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torr ...

. However, in 2002 it was shown that these two species differ both morphologically and genetically, and therefore ''C. canni'' was separated and described as a unique species.

Taxonomy

:Order: Testudines

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

, 1758 :Suborder: Pleurodira

Cope The cope (known in Latin as ''pluviale'' 'rain coat' or ''cappa'' 'cape') is a liturgical vestment, more precisely a long mantle or cloak, open in front and fastened at the breast with a band or clasp. It may be of any liturgical colour. A c ...

, 1864 :Family: Chelidae Ogilby, 1905 :Subfamily: Chelodininae Baur, 1893: 211 Baur G (1893). "Notes on the classification and taxonomy of the Testudinata". ''Proceedings of the American Philosophical Society'' 31: 210–225. ''Type data'' - Holotype: NTM 24515; an adult female (carapace length, CL = 215.3 mm; carapace width, CW8 = 167.2 mm), preserved in alcohol; collected with the help of local aboriginal people at Malogie Waterhole, near Scarlet Hill on Kalala Station (16° 08' S, 133° 36' E),

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an Australian territory in the central and central northern regions of Australia. The Northern Territory shares its borders with Western Aust ...

, Australia. ''Etymology'' - This species is named in honour of John Robert Cann (born 1938) of Sydney, Australia for his lifetime of work with the freshwater turtles of Australia. ''Taxonomic History'' - For many years this species was considered to be a secondary and disjunct population of ''

Chelodina novaeguineae The New Guinea snake-necked turtle (''Chelodina novaeguineae'') is a species of turtle in the family Chelidae. The species is found almost exclusively within Western Province, Papua New Guinea.Turtle Taxonomy Working Group hodin, A.G.J., Iverson ...

'' Boulenger, 1888. In recent years many started to believe that this was not the case. An attempt to describe it as ''Chelodina rankini'' was made by Wells and Wellington (1985) however this was shown to be a ''nomen nudum'' by Iverson et al., 2001, the species was finally described by William McCord and Scott Thomson in 2002. Subfamilies were resurrected for this family after it was discovered that the South American and Australian members are reciprocally monophyletic, that is they each have their nearest relatives within the continent ( Georges et al., 1998).

Description

Adults of ''C. canni'' can be diagnosed by the wide, rounded carapace with a moderately deep midvertebral trough; a median carapacial keel either absent or minimal, being most observable in the eastern populations; a wide plastron with dark seams on an otherwise uniformly yellow plastron; first and second marginal scutes equal or nearly equal in dorsal surface area; wide head with a red to pink suffusion on the head, neck, and limbs; and bluntly pointed neck tubercles. Hatchlings have an extensive orange-red ventral head, neck, and plastral pattern extending well onto the dorsal aspect of the marginal scutes.

Distribution

''C. canni'' is known from the

Roper River The Roper River is a large perennial river located in the Katherine region of the Northern Territory of Australia. Location and features Formed by the confluence of the Waterhouse River and Roper Creek, the Roper River rises east of Mataranka ...

drainage (including Maria Island in the Gulf of Carpentaria) in

, eastward through the drainages of the Gulf of Carpentaria in northwest

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...

. In Cape York it is found in drainages from Cairns in the north down to Rockhampton in the south where a narrow hybrid zone with '' C. longicollis'' is found ( Georges et al., 2002).Georges A, Adams M, McCord W (2002). "Electrophoretic delineation of species boundaries within the genus ''Chelodina'' (Testudines: Chelidae) of Australia, New Guinea and Indonesia". ''Zoological Journal of the Linnean Society'' 134 (4): 401-422.

References

External links

Carettochelys.com Cann's Snake Neck Turtle
* {{Taxonbar , from=Q1941409 Turtles of Australia Reptiles described in 2002 Taxa named by Scott A. Thomson Chelodina