A fascinating account of an investigation into the lost marsupials of the Flinders Ranges appears in the July 1992 Habitat, the magazine of the Australian Conservation Foundation.
Linguist Dorothy Turnbridge had been working with the Adnyamathanha Aboriginal community at Nepabunna for many years when she started developing a writing system for the local language, so it could be taught at school.
"One day, Annie Coulthard, the most knowledgeable person in the community and my senior adviser, sang me a lullaby about a little girl who became lost at Martin's Well while wearing a long urnda skin cloak."
But no-one knew what an urnda was. Other words were soon added to the list: warda, yarlpu, iknya, urli ...
Turnbridge, ignorant about native mammals, but with an "insatiable curiosity about language", set about trying to find out the identity of the animals. Because animals hold such cultural significance for Aboriginal people, Turnbridge found she could glean information about the missing animals from stories passed on by word of mouth.
Urdlu was quickly matched to the red kangaroo, and andu was found to be the yellow-footed rock wallaby.
But what about the urnda?
The late Rufus Wilton told Turnbridge that his mother (probably born before 1880) used to sing the lullaby about the lost child, but because the urnda died out before he was born in 1909, she substituted the name andu. His father had described the urnda as a small,
light-coloured wallaby.
Turnbridge began to build up a file on the missing animals, gleaning information on their habits and diets. She invited three zoologists to bring a set of mammal skins to the Adnyamathanha community. The late Claude Demell picked out a bilby skin and said his father had shown him a dead one of those some time before 1920, and named it yarlpu.
"Later, in a deeply moving moment in the Nepabunna Aboriginal School, the whole community listened as the late Lynch Ryan, holding a bilby skin in his arms and stroking it gently, explained, 'This is my brother'. He went on to tell stories about this, his totem animal. No-one would have guessed that this species had virtually disappeared before Mr Ryan was born."
Turnbridge kept piecing together fragments of information about the urnda: it ran into hollow logs when chased, it lived both in the ranges and on the plains in scrubby country; it was good for food, and its fur made a good water bag or blanket.
"And finally, it was described on Yorke Peninsula as 'the white shouldered wallaby' — a description later confirmed by an Adnyamathanha man, Eric McKenzie, who had had it from his elders."
The description perfectly matched the extinct crescent nailtail wallaby. But here Turnbridge ran into a problem: evidence of the animal's existence in the area had never been documented by western science.
Turnbridge combed historical records, and began to find references which suggested the animal lived throughout the entire Gulfs region. Finally, she came across the piece of hard evidence that would satisfy the zoologists. An Adelaide science teacher, Graham Medlin, helped by his students, had
amassed a vast Flinders Ranges fossil collection. Among these: a fragment of bone from the crescent nailtail wallaby, or, to use its ancient name, the urnda!
"All in all", she wrote, "the linguistic, cultural, historical and scientific evidence of our research indicated that, at the time of European settlement, there were around 55 native mammal species in the Flinders Ranges region — more than twice the number previously believed to have been present."