What was the vegetation in northwest Australia during the Paleogene, 66–23 million years ago?

Paleogene vegetation in Kakadu National Park, Australia, was dominated by Casuarinaceae, a family of evergreen shrubs and trees, indicating seasonally dry conditions similar to modern Allocasuarina/Casuarina formations. Fossil pollen and spores from drill cores reveal rare temperate rainforest elements like Dacrydium and Nothofagus subgenera, suggesting moist gorges on the Arnhem Land Plateau. No Laurasian rainforest elements were found, but some taxa with tropical affinities hint at warmer, wetter climates during the Paleocene-Eocene. This study provides the first record of plant communities in northwest Australia's coast and hinterland from 66 to 23 million years ago.

Macphail, M. K., & Hill, R. S. (2018). What was the vegetation in northwest Australia during the Paleogene, 66–23 million years ago? Australian Journal of Botany, 66(7), 556–574. https://doi.org/10.1071/bt18143