New Order of Ancient Marsupials Discovered in Australia

Paleontologists have described a new genus and three new species of small, insect-eating marsupials from the Early Miocene deposits of the Riversleigh World Heritage Area in Queensland, Australia.

The newly discovered species—Phantasmodon travouilloni, Phantasmodon minuferox, and Keeunidae sp.—lived approximately 18 million years ago and ranged in size from 25 to 200 grams.

"Not only is it a new order, but it could also be one of the most ancient lineages of Australian marsupials."
— Dr. Tim Churchill, University of New South Wales

A New Branch on the Marsupial Family Tree

These species belong to a newly recognized branch of marsupials called Keeunamorphia, which is proposed as a new order within Australidelphia. The Keeunamorphia lineage includes six species total: the three new species, plus Keeuna woodburnei, Ankotarinja tirarensis, and Djarthia murgonensis—Australia's oldest known marsupial, from 55-million-year-old deposits.

Ancient Origins, Mysterious End

The Keeunamorphia lineage may represent some of Australia's earliest marsupials, with possible origins in Gondwana. The lineage appears to have gone extinct during the Miocene, with no known descendants.

The study suggests that Australia was home to multiple primitive marsupial lineages during Gondwanan times, contributing to the diversity seen today.

"Evolutionary history is a lot more complex than just one group leading to all of Australia's marsupials."
— Dr. Tim Churchill

Publication Details

The research was published in the Journal of Paleontology on June 14, 2026.