Elseya dentata

(Gray, 1863b)
Northern Australian snapping turtle

Recognition
The oval (to 40 cm), flattened adult carapace usually is broadest behind the center, lacks a medial keel, and has a smooth posterior rim. Hatchlings and juveniles have a medial keel and strongly serrated posterior marginals on their round carapaces. Neural bones are absent, as is also a cervical cute. Vertebral scutes are usually broader than long, but the 2nd through 4th may be longer than broad in large females; the 1st and 5th are the smallest; the 1st is somewhat flared anteriorly, and the 5th is expanded posteriorly. Carapacial scutes are very rugose in texture. The carapace is olive gray to dark brown or black. Both sexes may become melanistic with age (Goode, 1967). The plastron is long and narrow, leaving much of the carapacial opening uncovered. Its forelobe is broader at its base than is the hindlobe, tapers toward the front, and is rounded or pointed anteriorly. The hindlobe tapers toward the rear and is posteriorly notched. The bridge is broad. The intergular scute is long and narrow (more than twice as long as broad), and it completely separates the gulars. The plastral formula is: pect >< fem > abd >< an > intergul > gul > hum. Plastron and bridge change from cream or yellow to gray brown or black with age. The head is large with a projecting snout and an unnotched to slightly notched upper jaw. The triturating surface of the maxilla bears a medial ridge. Dorsally, the head is covered with a large horny plate instead of smooth skin, and there are two chin barbels. The dorsal surface of the neck is covered with large blunt tubercles. Head, neck, and limbs are gray to olive or dark brown, and on the side of the head a broad, light stripe extends from below the orbit to the neck. The jaws are yellow to horn colored.
The karyotype consists of 50 chromosomes (Bull and Legler, 1980).
Males have longer, thicker tails than do females.

Distribution
Elseya dentata occurs in the rivers of northern Australia from the Kimberley district of Western Australia eastward through the Northern Territory to the Burnett River in southeastern Queensland. A number of populations currently assigned to Elseya dentata will be described as separate species. See Undescribed Taxa under Genus Elseya for their distributions.

Habitat
Elseya dentata inhabits large rivers and associated lagoons and oxbow lakes. Legler and Cann (1980) found them in riffles, deep pools, stretches with slow current, and areas with dead wood. Apparently it aestivates underground during dry periods (Cann, 1978).

Geographic Variation
At least five populations that currently are assigned to Elseya dentata may be regarded as separate taxa; see Genus Elseya for more information and pictures.

Natural History
Nesting occurs from April to July (Legler, 1985), with hatching about six months later. The brittle-shelled eggs are elongated (46.7-56.9 x 25.7-32.7 mm; Legler, 1985), and three to five constitute a normal clutch.
Elseya dentata is omnivorous. Kennett and Tory (1996) reported plant materials in 65.5%, aquatic invertebrates in 18.7%, and remains of terrestrial invertebrates in 15.6% of the turtles they examined. Riparian trees provide most of the food intake (leaves and fruits [mostly Ficus], seeds, flowers, bark and roots). Aquatic invertebrates eaten are insects, shrimp, and freshwater sponges; terrestrial invertebrates taken are almost all insects. Some fish, amphibians and carrion may also be consumed.
This turtle may be very aggressive when first captured, and large individuals can deliver severe bites; however, after a while in captivity they usually become tame.

IUCN Red List Status (1996)
Not listed.

Kingdom Animalia
Phylum Chordata
Class Reptilia
Subclass Anapsida
Order Testudines
Suborder Pleurodira
Family Chelidae
Genus Elseya
Species Elseya dentata

Northern Australian snapping turtle [English]

Emydure happante à dos bombé [Français]

Elseya-Schildkröte [Deutsch]

Noord-Australische bijtschildpad [Nederlands]

Bull, J. J., and J. M. Legler. 1980. Karyotypes of side-necked turtles (Testudines: Pleurodira). Canadian J. Zool. 58: 828-841.

Cann, J. 1978. Tortoises of Australia. Angus and Robertson, Publ., Sydney. 79 pp.

Goode, J. 1967. Freshwater tortoises of Australia and New Guinea (in the family Chelidae). Lansdowne Press, Melbourne. 154 pp.

Gray, J. E. 1863b. On the species of Chelymys from Australia, with the description of a new species. Ann. Mag. Natur. Hist. (London) (3)12: 98-99.

Kennett, R., and O. Tory. 1996. Diet of two freshwater turtles, Chelodina rugosa and Elseya dentata (Testudines: Chelidae) from the wet-dry tropics of northern Australis. Copeia 1996: 409-419.

Legler, J. M., and J. Cann. 1980. A new genus and species of chelid turtle from Queensland, Australia. Los Angeles Co. Mus. Natur. Sci. Contrib. Sci. (324): 1-18.

Legler, J. M. 1985. Australian chelid turtles: reproductive patterns in wide-ranging taxa. In: G. Grigg, R. Shine, and H. Ehmann (eds.), Biology of Australasian frogs and reptiles, pp. 117-123. Surrey Beatty & Sons, Chipping Norton, New South Wales, Australia.

McDowell, S. B. 1983. The genus Emydura (Testudines: Chelidae) in New Guinea with notes on the penial morphology of Pleurodira. In: A. G. J. Rhodin and K. Miyata (eds.), Advances in Herpetology and Evolutionary Biology, pp. 169-189. Mus. Comp. Zool. Harvard, Cambridge, Mass.

Elseya dentata
Elseya dentata 2
Elseya dentata 3 (close-up of head)
Elseya sp (S Alligator R) (undescribed form from northwestern Northern Territory—see genus Elseya)
Elseya sp (Roper R) (undescribed form from northeastern Northern Territory—see genus Elseya)
Elseya sp (Nicholson R) (= E. lavarackorum from northwestern Queensland—see genus Elseya)
Elseya sp (Johnstone R) (female (left) and male; undescribed form from coastal eastern Queensland—see genus Elseya)
Elseya sp (Burdekin R) (= E. irwini from coastal eastern Queensland—see genus Elseya)
Elseya sp (Raglan R) (undescribed form from coastal eastern Queensland—see genus Elseya)