Location of tooth, which belonged to megalodon shark, had been kept secret from public

The fossilised tooth of a giant prehistoric shark has been stolen from its secret location in a world heritage site in Western Australia, in what officials believe was a planned operation.

The rare item, which belonged to the 15m, 20-tonne megalodon shark, was discovered by staff at the Cape Range national park but the site was kept secret from the public.

Arvid Hogstrom from Parks and Wildlife Western Australia said staff had planned to turn the fossil, which was embedded in rock, into an educational exhibit and were working to encase it in glass when it vanished.

He said it had to have been stolen by someone with prior knowledge of its location. “It’s in a fairly remote site and our staff don’t visit it on a daily or weekly basis,” he said. “We had a report last Friday that it was no longer there. Someone would have obviously needed to know where it was and actually make an effort to remove it from the rock.”

The missing tooth was one of several megalodon teeth found across the Ningaloo Coast, a world heritage site in north-west WA.

“There are a few of these spread throughout the range but this one was a particularly good specimen because it was almost complete,” Hogstrom said. “It gives you a good idea of how vicious and voracious it was back in the day.

“[The thieves] probably would have used a chisel and unfortunately the reason why this one has gone was it wasn’t all that embedded in the rock.”

Hogstrom called on the public to keep an eye out for the tooth. “Perhaps the person who has taken it doesn’t realise the significance of what they’ve taken,” he said. “Or if someone sees this at somebody’s home, just let us know.”

Megalodon is thought to have lived 23m to 2.6m years ago and some estimates of its size make it the largest known fish that has ever lived. Megalodon teeth are roughly 7cm measured diagonally, with an estimated 250 teeth in the jaw of an adult shark.

“It’s a unique bit of history from a world heritage area that was there for everyone to enjoy,” Hogstrom said. “We’d love to have it returned.”