Scientists from UNSW say they have identified three fossil species that may belong to a previously unknown branch of Australia’s marsupials, according to ScienceDaily. The findings were published in the Journal of Paleontology.
Lead researcher Dr. Tim Churchill says the animals could represent a new order, which the team has named Keeunamorphia. He said the group may be among the most ancient lineages of Australian marsupials and could even be an early ancestor of marsupial carnivores.
The fossils date to about 18 million years ago and were found at Riversleigh in far north Queensland, where shallow cave pools helped preserve parts of the animals. Because complete skeletons are rare, the researchers worked mainly from teeth and jaw fragments.
By combining fossil evidence with genetic data from living species, the team built a phylogenetic tree to place the animals in the marsupial family tree. Their analysis suggests the group may have existed for about 35 million years before disappearing around 15 million years ago, during a time when the region’s environment shifted from dense rainforest to more open woodland.
Dr. Churchill said the discovery adds to evidence that marsupial evolution in Australia was more complicated than a single early lineage giving rise to all modern groups. He noted that major gaps in the fossil record still leave much of the continent’s early marsupial history unknown.
