Ancient species of snail-eating mammal found in Australia

A never before seen species of an ancient mammal has been found in a cage at Riversleigh World Heritage Fossil Site in Australia. Researchers from the University of New South Wales discovered the  15 million old marsupials while investigating the cave.

Australia has been categorized as the most valued continent when it comes to fossil discoveries, thanks to its total isolation from the world for 35 million years when it separated from Antarctica.

The continent features two of the most valued fossil discovering sites, Riversleigh World Heritage located at north Australia and Naracoorte World Heritage site located in the south of the continent.

For years the locations have provided a massive amount of ancient mammal fauna, giving researchers the opportunity to understand how the world’s habitat and fauna worked 30 million years ago.

The main species found at both of the heritage sites belong to both the Oligocene and the Miocene period, which occurred 10 to 30 million years ago. The Naracoorte Heritage site has also provided information about the mid-Pleistocene period and about the world’s climate changes and its evolution.

In both of the fossil-rich sites, researchers can find evidence about the gradual evolution that has occurred in the continent’s fauna and has a better understanding of the family and lineage of the mammals living in the isolated continent.

Thanks to different mammal discoveries, researchers have been able to determine the climate change that has occurred in the continent. From rainforests to dry eucalypt forests the environment of the continent has evolved throughout the history of the world.

New mammal species found

Researchers from the University of South Wales discovered the Malleodectes mirabilis species, that has been estimated to have lived 15 million years ago.

Research on the mammal’s teeth structure has determined it had a larger premolar teeth similar to a modern day hammer used to crack open and feed on snail shells, yet it might have also used small prey’s vertebrates as a food resource. Researchers have confirmed this is the first time a mammal fossil has been found to be so well preserved.

The Malleodectes mammal belonged to the Miocene period, researchers assure, and it has been linked to other mammals species such as the Dasyuridae, the Myrmecobiidae, and the Thylacinidae.

The mammal’s environment was Australia’s rainforest and it is believed to be the last ancient species to have lived in the location since the Miocene.

The fossil belongs to a teenager mammal of the species that was found in a limestone cave at the Riversleigh World Heritage Fossil site located at northwestern Queensland in Australia.

The cave has been considered one of the richest fossils sites in the world, despite being deteriorated over time the floor remains steady and full of future fossils discoveries of ancient animals that lived or got trapped in the cave.

Description of the mammal

Researchers used a previously designed software to calculate the mass of the mammal’s body, which used an  equation of the species body mass. It concluded that the Malleodectes mirabilis weighted around 896 grams.

Using the skull of the fossil, researchers were able to determine the mammal had baby teeth and adult teeth growing. Which lead investigators to understand the relationship of the species with the dasyures a group of mammals and carnivores related to Tasmanian devils and tigers.

Study’s results concluded the mammal was smaller than their cousin members, less rounded, and had a lower head since it measured around 5.4 mm in width and, 6.7 mm long.

“The juvenile malleodectid could have been clinging to the back of its mother while she was hunting for snails in the rocks around the cave’s entrance, and may have fallen in and then been unable to climb back out. Many other animals that lived in this lush forest met a similar fate with their skeletons accumulating one on top of another for perhaps thousands of years until the cave became filled with palaeontological treasures,” said Suzanne Hand, co-author of the study and professor of the University of South Wales.

According to investigators, the family of mammals became extinct thanks to an intense climate change that occurred in the continent, transforming Australian rain forests into dry lands.

Other species found

Countless fossils have been found at the Australian World Heritage site throughout the years, which has given investigators a view of strange families of extinct animals.

Species such as woodpeckers who used their teeth to obtain bugs to feed and extinct kangaroos. Other species include ancient crocodiles families that dropped out of trees to catch their prey as well as 10 feet tall birds.

It is yet to be seen the discoveries Riversleigh World Heritage fossil center and the Naracoorte fossil heritage location will provide the scientific world with, to get a better understanding of ancient species and the world’s evolution.

Source: Nature