When did the kangaroo rat become endangered?

It is uncertain whether or not the desert rat kangaroo is truly extinct. It was only discovered in 1841 from 3 specimens collected from somewhere in South Australia (Gould's description of the type locality is very vague). This was the last record of the species for ninety years until it was rediscovered in 1931 by Hedley Herbert Finlayson, Curator of Mammals at the South Australian Museum.

The last confirmed record of the species was in 1935 near Ooroowilanie, east of Lake Eyre, but some scientists believe that, as it is/was a very elusive creature it could still exist in the remote desert. It is/was also nocturnal as well, which lends support to the possibility of it having evaded collection again. However, it is most probably extinct as its known habitat was quite restricted.

It was formally listed as extinct nationally under the Environment Protection and Biodiversity Conservation Act 1999. In Queensland it was formally listed as extinct Extinct in the Wild under the Nature Conservation Act 1992. However, in South Australia it was listed as Endangered under the National Parks and Wildlife Act 1972, and has not been formally recognised as extinct.