Platypuses existed as oddities since near the end of the age of dinosaurs when Steropodon, the first platypus-like species, appeared in ancient Australia’s fossils. Paleontologists once believed the anomalous animals evolved solo, with only one platypus species living on Earth at a time.

This is the first lower molar of the new giant platypus, Obdurodon tharalkooschild. Photo by R. Pian.

However, a newly discovered extinct 3-foot-long platypus suggests multiple species of the mixed-up mammals swam ancient Australian waters at the same time.

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“Discovery of this new species was a shock to us because prior to this, the fossil record suggested that the evolutionary tree of platypuses was relatively linear one,” said Michael Archer of the University of New South Wales, a co-author of the study that described the giant platypus in the Journal of Vertebrate Paleontology, in a press release. “Now we realize that there were unanticipated side branches on this tree, some of which became gigantic.”

All that remains of the giant platypus, named Obdurodon tharalkooschild, is a single tooth. The tooth dates to between five and 15 million years ago. Like much of the rest of the playtpus, the tooth was unique enough to identify the creature and hint at its lifestyle.

“Like other platypuses, it was probably a mostly aquatic mammal, and would have lived in and around the freshwater pools in the forests that covered the Riversleigh area millions of years ago,” said co-author Suzanne Hand of the University of New South Wales in a press release. “Obdurodon tharalkooschild was a very large platypus with well-developed teeth, and we think it probably fed not only on crayfish and other freshwater crustaceans, but also on small vertebrates including the lungfish, frogs, and small turtles that are preserved with it in the Two Tree Site fossil deposit.”

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Platypuses’ bodies feature a bizarre grab-bag of biology. Platypuses eat with rubbery-bills that can sense electromagnetic energy fields. Their body temperature only reaches 90 degrees Fahrenheit.  They waddle on land on their knuckles, like gorillas, with their legs splayed like lizards. The animals swim using a hairy, beaver-like tail packed with fat to help them survive starvation. Platypuses’ ear openings lie beneath their jaws. The males sport venomous spikes on their elbows. Females lay eggs, instead of giving birth.

No wonder comedian Robin Williams believed that the duck-billed platypus was proof that God partook in cannabis-consumption occasionally.

Top Image: An illustration of Obdurodon tharalkooschild, a middle to late Cenozoic giant toothed platypus from the the World Heritage fossil deposits of Riversleigh, Australia. At about one meter (more than 3 feet) in length and with powerful teeth (inset: the holotype, a first lower molar), it would have been capable of killing much larger prey, such as lungfish and even small turtles, than its much smaller living relative. (Illustration by Peter Schouten)