Toothed Platypus Swam with Dolphins 25 Million Years Ago

Deep in the Australian outback, paleontologists just uncovered fossils that rewrite the story of one of nature's oddest creatures: the platypus.

The team from Flinders University found well-preserved remains of Obdurodon insignis, a toothed ancestor of today's toothless platypus. This ancient relative lived 25 million years ago in vast freshwater lakes and slow-flowing rivers that once covered what is now desert.

Dr. Aaron Camens says the discovery is remarkable because platypus fossils are incredibly rare. "They're often restricted to teeth, so it's exciting to find new material and learn more about these unique mammals," he explained.

The ancient platypus looked surprisingly similar to its modern cousin, with one major difference: a mouthful of serious chompers. While baby platypuses today lose their tiny teeth shortly after birth and use only horny pads to mash food, Obdurodon insignis kept large molars, premolars, and pointed front teeth throughout life.

Professor Trevor Worthy says those powerful jaws could easily crush freshwater shrimp and other animals with hard shells. The creature was slightly larger than modern platypuses but swam and moved in much the same way.

The fossil site has yielded more than a thousand vertebrate specimens over 20 years of expeditions. Yet only three belong to the toothed platypus, making each discovery precious.

Why This Inspires

The fossils paint a picture of a lost world that feels almost magical. These ancient lakes teemed with lungfish and small dolphins, yes, dolphins living in freshwater alongside the platypus. Overhead, a giant eagle called Archaehierax soared above rainforests filled with koalas, possums, and sheep-sized marsupials browsing below.

That entire ecosystem vanished as Australia's climate shifted toward the arid conditions we see today. The rainforests dried up, the lakes disappeared, and most species went extinct or moved elsewhere.

But platypuses? They kept swimming. Through millions of years of dramatic climate change, they adapted, survived, and still paddle through Australian waterways today, a living link to that ancient world.

Professor Worthy returns to the desert year after year, knowing erosion might reveal the next incredible fossil. "One never knows what one's efforts will reveal next," he said.

The platypus has been defying expectations for 25 million years and counting.