A 5-million-year-old fossil belonging to a pig-nosed turtle that was unearthed in Melbourne, Australia, has re-written the creature’s long history.
Pig-nosed turtles are freshwater creatures that are native to the northern part of Australia and the southern part of New Guinea. Their feet contain paddle-like flippers and their nose looks like that of a pig. They mostly live in the water but nest on land. They are omnivores that feast plants (like fig leaves and fruit) in addition to insects, mollusks, and crustaceans. They can grow to 70 centimeters in length (28 inches or 2.3 feet) and weigh more than 20 kilograms (44 pounds). They live between 25 and 30 years.
It was previously believed that the pig-nosed turtle, which is the last surviving member of the carettochelyids tropical turtle group, came to Australia in the last few millennia. However, a recent study has shed new light on when they actually arrived.
An unidentified ancient fossil that was found in Beaumaris near Melbourne was kept in a collection at the Melbourne Museum for the past 100 years. The fossil fragment has recently been analyzed and experts realized that it actually belonged to a pig-nosed turtle. This discovery has brought back the creature’s arrival time to millions of years earlier than previously thought.
Another interesting fact was that the fossil was found thousands of kilometers away from where today’s pig-nosed turtles currently reside. This may be explained by the different climate that Australia had millions of years ago as it was a lot hotter and wetter in Melbourne than it is today – the type of conditions that the turtles could survive in. This makes a lot of sense since Beaumaris was also once home to monk seals and dugongs.
Climate change is the reason why the pig-nosed turtle is the last surviving member of the carettochelyids group. In fact, after the Ice Ages when Australasia’s climate was cooler and drier, all of the tropical turtles went extinct with the exception of the pig-nosed turtle which survived in northern Australia and southern New Guinea. The species is, however, considered endangered.
Dr. James Rule from the Monash University School of Biological Sciences weighed in on the discovery by stating, “This one fossil specimen reveals a previously unknown evolutionary history of tropical turtles in Australia, and suggests we still have much to learn about the endangered pig-nosed turtle.” Their study was published in the journal Papers in Palaeontology where it can be read in full.
A picture of the 5-million-year-old pig-nosed turtle shell fragment can be viewed here.