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Huge Tooth Reveals Prehistoric Moby Dick in Melbourne

Dr Erich Fitzgerald with the fossilised extinct sperm whale tooth.
Dr Erich Fitzgerald with the fossilised extinct sperm whale tooth.

Long walks on the beach will never be quite the same for local Melbourne man Murray Orr. The keen-eyed fossil enthusiast has collected the largest tooth ever found in Australia at Beaumaris Bay, a renowned fossil site in Melbourne’s south-east.

“After I found the tooth I just sat down and stared at it in disbelief. I knew this was an important find that needed to be shared with everyone,” recounts Mr Orr.

The tooth – of an extinct species of sperm whale closely related to Livyatan melvillei from Peru– is of international significance and represents the only example of its size and kind ever to be discovered in Australia. Indeed, the new discovery from Beaumaris is the first evidence of such a gigantic ‘killer sperm whale’ outside of the Americas.

At about 30 cm long and dating from the Pliocene epoch (approximately 5 million years ago), the tooth is larger than the teeth from a living sperm whale and even exceeds the dental dimensions of the mighty Tyrannosaurus rex. The Beaumaris tooth originated from an extinct sperm whale up to 18 metres long and weighing perhaps 40 tonnes (40,000 kgs).

Recognising the significance of the discovery, Murray Orr contacted Dr Erich Fitzgerald, Senior Curator of Vertebrate Paleontology at Museum Victoria with an offer to donate the tooth to the Museum collection – an offer gratefully accepted by Dr Fitzgerald. “By donating his discovery to Museum Victoria, Murray has ensured that this unique fossil is available for scientific research and education both now and for generations to come. This is absolutely essential for documenting and preserving Australia’s fossil heritage.”

Unlike the living sperm whale, which lives off a diet of squid and fish, the extinct ‘killer sperm whales’ (including Livyatan and the Beaumaris fossil) probably preyed upon much larger animals such as other whales. This is suggested by the size and shape of their teeth, which in the Peruvian fossils of Livyatan are set in large jaw bones indicating powerful jaw-closing muscles.

As Dr Fitzgerald explains, these fossils provide an important perspective on today’s sperm whales. “If we only had today’s deep-diving, squid-sucking sperm whales to go on, we could not predict that just 5 million years ago there were giant predatory sperm whales with immense teeth that hunted other whales. Most sperm whales for the past 20 million years have been of the whale-killing kind. So, the fossil record reveals the living species to in fact be the exception to the rule, the oddball of the sperm whale family.”

The new discovery cements Beaumaris Bay as one of Australia’s premier fossil sites, explains Dr Fitzgerald:

“In all of the 34,000 km of Australia’s coastline, Beaumaris Bay is unique. 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. It is a national treasure.”