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

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

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

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

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 ...

. The species is

endemic Endemism is the state of a species being found only 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 foun ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, 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''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

. 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 ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

1758 Events January–March * January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of ''Systema Naturae'', the starting point of modern zoologic ...

:Suborder: Pleurodira

Cope A cope ( ("rain coat") or ("cape")) is a liturgical long mantle or cloak, open at the front and fastened at the breast with a band or clasp. It may be of any liturgical colour. A cope may be worn by any rank of the Catholic or Anglican clerg ...

, 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 (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

, Australia. ''Etymology'' - This species is named in honour of John Robert Cann (born 1938) of

Sydney Sydney is the capital city of the States and territories of Australia, state of New South Wales and the List of cities in Australia by population, most populous city in Australia. Located on Australia's east coast, the metropolis surrounds Syd ...

, 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'' 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 A carapace is a 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 tortoises, the unde ...

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 The Gulf of Carpentaria is a sea off the northern coast of Australia. It is enclosed on three sides by northern Australia and bounded on the north by the eastern Arafura Sea, which separates Australia and New Guinea. The northern boundary ...

) in

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

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

. In Cape York it is found in drainages from

Cairns Cairns (; ) is a city in the Cairns Region, Queensland, Australia, on the tropical north east coast of Far North Queensland. In the , Cairns had a population of 153,181 people. The city was founded in 1876 and named after William Cairns, Sir W ...

in the north down to

Rockhampton Rockhampton is a city in the Rockhampton Region of Central Queensland, Australia. In the , the population of Rockhampton was 79,293. A common nickname for Rockhampton is "Rocky", and the demonym of Rockhampton is Rockhamptonite. The Scottish- ...

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