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, Australia.

[4] Taxonomic History - For many years this species was considered to be a secondary and disjunct population of Chelodina novaeguineae Boulenger, 1888.

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 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.