A reconstructed map of the new species Mukupirna nambensis 25 million years ago, with hard-tailed ducks and flamingos excavated at the same site. (Drawing by Peter Schouten)
Beijing, June 26 (Reporter Sun Zifa) The latest paleontological research paper published by Science Report, an international academic journal of natural scientific research, said that researchers have discovered and reported a new species of ancient marsupial in South Australia, which represents one of the oldest Australian marsupials known to have been excavated, and its anatomical characteristics help the academic community to further understand the evolution of modern wombats and their typical burrowing behavior.
Robin Beck, a paleontologist at the University of Salford in the United Kingdom, and others have found that the fossil dates back to the late Oligocene (about 25-26 million years ago) and belongs to a new species of the suborder Wombats through a skull and part of the skeleton excavated in the Lake Eyre Basin in South Australia.
The suborder Wombats were once one of the most diverse marsupial evolutionary groups, with only 3 species in the family Wombats and koalas still surviving. Robin Baker et al. named the newly discovered species "Mukupirna nambensis", which is derived from the "muku" (bone) and "pirna" (large) in the Dieri and Maliyangapa languages spoken around Lake Eyre and Lake Fromm, and its weight is estimated to be 143-171 kg, about 5 times that of the extant wombat species.
Photo of a fossil skull of a new species, with the anterior side of the skull above the picture, with a total length of 19.7 cm. (Image courtesy of Julien Louys of Griffith University and Robin Beck, University of Salford)
According to the authors, some of the anatomical features identified from the skeleton point to burrowing behaviors, such as adaptations to the forearm commonly found in burrowing animals. However, fossil evidence from previous excavations dating back to a later period suggests that Mukupirna was less adapted to the habit of digging than its late-age close relatives. This, along with the new species size, suggests that Mukupirna may not have the true burrowing abilities of modern wombats, but may be able to obtain food such as plant roots beneath the surface by scraping.
Robin Baker et al. also point out in the paper that another typical adaptation of extant wombat species is specialized molars that can grow sustainably, but mukupirna does not either, suggesting that during the evolution of wombats, the skeletal anatomy used for mining adapted earlier than tooth changes. (End)