| Tortoises of
Australia Telling the Difference Between
Species
Australian tortoises are divided into three groups: long necks, short necks, and the
Pig-nose Turtle. There are five genera - Chelodina, Emydura, Elseya, Pseudemydura
and Carettochelys - which encompass the described species. Grouped with these
known species are a number of populations still to be described, sot the present total of
distinct species can be regarded as temporary.
Many obstacles must be overcome before the complicated relationship
between the Australian tortoises is completely understood. Tortoises of the same species
may vary slightly in characteristics from one river system to the next. This often results
in specimens from opposite extremes of a distribution chart being markedly different in
appearance. To determine the point where a tortoise is no longer a geographical variation
but warrants a separate specific name is usually difficult.
A lot of the features used in identifying species are unreliable and
a foolproof key for identification has yet to be devised. John Goode (Freshwater
Tortoises of Australia and New Guinea) published one based on the knowledge available
in 1967; this has yet to be extended. At this stage, for the beginner, the best means of
identifying the various types of tortoises is from photographs.
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