| Cann's snake-necked turtle | |
|---|---|
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Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Testudines |
| Suborder: | Pleurodira |
| Family: | Chelidae |
| Genus: | Chelodina |
| Subgenus: | Chelodina |
| Species: | C. canni |
| Binomial name | |
| Chelodina canni | |
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| Distribution ofC. canni in Australia. | |
| Synonyms[2] | |
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Chelodina canni, also knowncommonly asCann's snake-necked turtle, is aspecies ofturtle in thefamilyChelidae. The species isendemic toAustralia, where it is found in the northern and northeastern parts of the continent.[1] It has a narrow zone ofhybridization with its related species the eastern snake-necked turtle,C. longicollis. For many yearsC. canni was assumed to be the same species asC. novaeguineae fromNew Guinea. However, in 2002 it was shown that these two species differ both morphologically and genetically, and thereforeC. canni was separated and described as a unique species.
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 onKalala Station (16° 08' S, 133° 36' E),Northern Territory, Australia.
Etymology - This species is named in honour of John Robert Cann (born 1938) ofSydney, Australia for his lifetime of work with the freshwater turtles of Australia.[4]
Taxonomic History - For many years this species was considered to be a secondary and disjunct population ofChelodina novaeguineaeBoulenger, 1888.[5] In recent years many started to believe that this was not the case. An attempt to describe it asChelodina rankini was made by Wells and Wellington (1985)[6] however this was shown to be anomen nudum byIverson et al., 2001,[7] the species was finally described byWilliam McCord andScott 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).[8]
Adults ofC. canni can be diagnosed by the wide, roundedcarapace 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.
C. canni is known from theRoper River drainage (including Maria Island in theGulf of Carpentaria) inNorthern Territory, eastward through the drainages of the Gulf of Carpentaria in northwestQueensland. InCape York it is found in drainages fromCairns in the north down toRockhampton in the south where a narrow hybrid zone withC. longicollis is found (Georges et al., 2002).[9]
