The genus Nimbacinus contains two species of carnivorous, quadrupedal marsupials in Australia both of which are extinct: Like all thylacinids, Nimbacinus dicksoni was a dog-like marsupial, though its smaller size makes its appearance more comparable to that of a fox.

[4] The name of the genus combines Nimba and cinus, derived from a word meaning "little" in the Wanyi language, indigenous peoples associated with the Riversleigh fossil site, and the Ancient Greek word kynos, meaning dog.

[1] The description of N. richi was published in 2000 by researchers Peter F. Murray, working at the Museum of Central Australia and Dirk Megirian of the Northern Territory Museum.

[5] The holotype is fossilised material excavated at "Top Site" at the Bullock Creek fossil area, a partial left dentary with a premolar and several molars that is dated to the mid-Miocene.

The specific epithet commemorates Tom Rich, who introduced the authors to the site of their discovery.