Giant killer sperm whales once cruised Australia's waters (and we have a massive tooth to prove it)

A gigantic pearly white, once belonging to a prehistoric sperm whale, has been unearthed in Melbourne, Australia. The tooth is the largest ever to be found in the country, and as you can imagine, after millions of years underground, it isn’t so pearly any longer.

Left: Dr Erich Fitzgerald, Senior Curator of Vertebrate Paleontology at Museum Victoria, with the fossil. © Ben Healley/Museum Victoria Right: Fossil enthusiast Murray Orr poses with his recent find. Image © Murray Orr

Melbourne local and fossil enthusiast Murray Orr discovered the 30-centimetre tooth while walking along the beach at Beaumaris Bay. “After I found the tooth I just sat down and stared at it in disbelief,” he recalls. “I knew this was an important find that needed to be shared with everyone.”

The massive tooth is believed to belong to an extinct species of “killer sperm whale” that cruised the world’s oceans during the Pliocene epoch, some five million years ago. This aquatic giant, closely related to Livyatan melvillei from Peru, reached lengths of 18 metres (59 feet) and weighed 40,000 kilograms (88,000 pounds).

While modern sperm whales live on a diet of squid and fish, it’s thought that these ancient behemoths would have used their impressive teeth to feast on smaller whale species.

Beaumaris killer sperm whale compared to a human. Supplied

The tooth is the only one of its kind ever to be discovered outside of the Americas, and was brought to Museum Victoria, where scientists like Dr Erich Fitzgerald, the Senior Curator of Vertebrate Palaeontology, are hard at work analysing the specimen. Even a single fossil tooth like this can offer important clues for researchers who are decoding the past.

“If we only had today’s deep-diving, squid-sucking sperm whales to go on, we could not predict that just five million years ago there were giant predatory sperm whales with immense teeth that hunted other whales,” says Fitzgerald. “The fossil record reveals the living species to in fact be the exception to the rule, the oddball of the sperm whale family.”

Fitzgerald adds that we can expect to see more exciting finds coming from Beaumaris Bay, as the site's rocks are of unique makeup and age. “Nowhere else on this continent produces the fossils being found at Beaumaris and provides such astonishing insights into the deep history of Australia’s marine megafauna.”

We suspect that parting with his amazing find was a little tough for Orr, but by donating it to the museum he has ensured it will be enjoyed by curious visitors for generations to come.

Left to right: Tyrannosaurus rex tooth, extinct sperm whale tooth and contemporary sperm whale tooth. © Ben Healley/Museum Victoria

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Header image: Brian Choo