It is notable for the occurrence of well-preserved, rare, Miocene vertebrate fossils, which provide evidence of the evolution of the Northern Territory’s fauna and climate.

The Alcoota and Bullock Creek fossil faunas provide evidence that aridification was in progress in northern Australia during the mid-Miocene geological time period.

This makes it especially interesting, as it lies between the older faunas of Kutjamarpu (Southern Australia) and Bullock Creek (Northern Territory) and the younger deposits of Riversleigh (Queensland) and Beaumaris (Victoria).

The individual lenses are about 1 m across and extend for 170 m. Bones and teeth are so abundant and often tightly packed, excavating one fossil without breaking the one below it can be difficult.

Also found at Alcoota are fossils of herds of the wombat-like diprotodontoids Kolopsis torus and Plaisiodon centralis, the trunked Palorchestes painei, Pyramios alcootense and other kangaroos, crocodiles, bandicoots, possums, and small birds.