Researchers have described a previously unknown order of marsupials based on fossils from northern Queensland. The findings suggest early Australian marsupial evolution was more complex than previously thought. The study was published in the Journal of Paleontology in 2026.
A team from UNSW has proposed a sixth order of marsupials, named Keeunamorphia. The three species lived around 18 million years ago in what is now the Riversleigh World Heritage Area.
Dr. Tim Churchill, the lead researcher, said the group may represent the most ancient lineage of Australian marsupials. He added that it could be the early ancestor of marsupial carnivores.
The animals were small insect eaters weighing 25 to 200 grams. Their teeth resemble those of a much older species from 35 million years earlier, indicating the lineage persisted for a long period.
The discovery challenges the view that all Australian marsupials descended from a single early group that arrived via Antarctica. Dr. Churchill noted that evolutionary history involved multiple primitive lineages surviving after the continent separated from Gondwana.