Ancient Predator Discovery Rewrites Australian Marsupial History

Researchers in northwestern Queensland, Australia, identified Miyumba chrisdickmani, a mouse-sized predator and the earliest known member of the dasyurid family of marsupials. The discovery pushes back the fossil record of dasyurids by over five million years, to approximately 23 million years ago.

For decades, scientists debated the origins of these carnivorous marsupials, with DNA evidence suggesting a relatively recent emergence despite the primitive design of their teeth. The new fossil, found in the Riversleigh World Heritage Area, exhibits a unique dental arrangement, a smaller third lower premolar, that definitively links it to the dasyurid lineage.

This feature provides a crucial marker for identifying early dasyurids in the fossil record. Analysis suggests Miyumba lived in rainforests and was related to modern New Guinean species, indicating that dasyurids initially evolved in wetter environments before diversifying into Australia’s deserts and woodlands. The finding may also explain the disappearance of an earlier group of predators, the keeunamorphians, as dasyurids potentially filled vacated ecological niches.