Mary River Turtle

The Mary River turtle, Elusor macrurus, is an endangered short-necked turtle that inhabits the Mary River in South-East Queensland, Australia. In the 1960s and 1970s, they were popular as pets in Australia, with about 15,000 sent to shops every year during a ten-year period. They were originally known as the "Penny Turtle" or "Pet Shop Turtle". Elusor is a monotypic genus representing a very old lineage of turtles that has all but disappeared from the evolutionary history of Australia.

The Mary River turtle is one of Australia's largest turtles. Specimens in excess of 50 cm carapace length have been recorded. Hatchlings have a straight carapace length of 2–3.5 cm. Adult Mary River turtles have an elongated, streamlined carapace that can be plain in colour or beautifully patterned. Overall colour can vary from rusty red to brown and almost black. The plastron varies from cream to pale pink. The skin colouration is similar to that of the shell and often has salmon pink present on the tail and limbs. The iris can be pale blue. Mary River turtles use bimodal respiration, and are therefore capable of absorbing oxygen via the cloaca whilst underwater. However, they do regularly come to the surface to breathe air in the usual way.

A unique feature of male Mary River turtles is the tail, which can measure almost two-thirds of the carapace length. The tail has haemal arches, a feature lost in all other modern turtles. It is probably a derived feature but its function is not understood. Another unique feature is the exceptionally long barbels under the mandible. Proportionately, the Mary River turtle has the smallest head and largest hind feet of all the species within the catchment, which contributes to its distinction of being the fastest swimmer.

This species is currently listed as endangered under Queensland's Nature Conservation Act 1992, and under the federal Environment Protection and Biodiversity Conservation Act 1999. The international conservation body, IUCN, lists it as endangered on the IUCN Red List. It is Australia's second most endangered freshwater turtle species, after the Western Swamp Tortoise (Pseudemydura umbrina) of Western Australia. Mary River turtles are also listed in the world's top 25 most endangered turtle species.

The Mary River Turtle was described by Cann & Legler (1994).

Australia's first reptile-focused, non-profit conservation organisation, The Australian Freshwater Turtle Conservation and Research Association, were the first to breed this species in captivity for release into the wild in 2007.