Historical evidence for provenance and collectors of holotypes of the north-western Australian red-faced turtles Emydura australis and E. victoriae (Testudines: Chelidae)

Taxonomic definitions are independent of zoological nomenclature, but names are vital to clear communication about taxonomic entities. Name-bearing type specimens provide the ultimate reference for names applied to species, but when a type specimen is accompanied by poor or vague information about its provenance its value for that purpose may be significantly diminished. John Edward Gray described the Australian red-faced turtle as Emydura australis in 1841.

In the following year he described Emydura victoriae also from northern Australia. While the description of E. australis said the type specimen was from the vague area of “ Western Australia?” subsequent publications by Gray variously repeated that information or suggested it might have come from the Victoria River in modern Northern Territory or from the distant Macquarie River in the south-east of Australia. This has resulted in much confusion about which name to apply to these turtles, to the point where many authors have ignored the name E. australis in favour of E. victoriae, a species described later but with the precise collection locality of Victoria River in modern Northern Territory.

Here we present a detailed investigation of historical information about the few potential collectors of the E. australis type specimen and the locations they visited where the specimen could have been obtained. On the basis of that evidence, we restrict the type locality of E. australis to a relatively small area including just three rivers of the western Kimberley region of Western Australia. By way of additional evidence, we compare a limited range of morphological parameters of the E. australis type specimen with extant Emydura from two of those rivers and that of E. victoriae.

We also resolve conflicting early information about the collector of the E. victoriae type specimen. Information we provide about provenance and thus status of E. australis offers a basis for improved communication about biology and taxonomy of the red-faced turtles of north-western Australia.