"These teeth are of international significance, as they represent one of just three associated groupings of Carcharocles angustidens teeth in the world, and the very first set to ever be discovered in Australia," Erich Fitzgerald, senior curator at the Museums Victoria public museums group, said in a statement on Thursday.
The Great Jagged Narrow-Toothed Shark could grow to more than nine meters long, almost twice the length of today's Great White Shark, about 25 million years ago and was a top predator that would have hunted small whales.
Fossil enthusiast Philip Mullaly first spotted the teeth, up to seven cm long, at Jan Juc along Victoria state's Surf Coast area, leading paleontologists to excavate the site up till early this year, according to the museum group.
"I was walking along the beach looking for fossils, turned and saw this shining glint in a boulder and saw a quarter of the tooth exposed. I was immediately excited, it was just perfect and I knew it was an important find that needed to be shared with people," said Mullaly.
The paleontologists also discovered teeth from the smaller sixgill shark species which might have fed on the carcass of their much larger cousin, making the Jan Juc spot one of the country's most important fossil sites, "as it continues to provide us with unique insights into the deep history of Australia's marine life including whales, dolphins, sharks and countless smaller marine animals," said the museum group.
The find of 45 shark teeth have been put on display at the Melbourne Museum in the state capital.