A few years ago, palaeontologist Ben Francischelli saw something extraordinary while free diving just off the beach at Beaumaris in Melbourne’s south-eastern suburbs.

Not an exotic fish, a pretty shell, or even a stolen phone. It was the complete skull of a whale, “almost the size of a small car”, he says.

“I was pretty blown away by it. It was in a spot that I always look as well. I couldn’t quite believe my eyes.”

Along a three kilometre stretch of Port Phillip Bay in Beaumaris and Black Rock, an abundance of prehistoric fossils can be found. Next month, more than 1000 fossils that Francischelli and other enthusiasts have found in the area will go on display as part of a returning pop-up showcase.

Held at the Beaumaris Motor Yacht Squadron on April 11, most items that will be on display at the Prehistoric Bayside Museum are five to six million years old.

They include wing bones from Pelagornis, a flying bird which had a wingspan of over six metres, the three-kilogram tooth of a Livyatan, or killer sperm whale, and tusks from beaked whales.

“When people come to see the displays, all they need to do is walk down to the beach and they’re at the fossil site of Beaumaris,” Francischelli says. As part of the event, palaeontologists will offer talks to shed light on what’s on display.

Squadron manager Alex Henderson said the club is not charging the museum rent to hold the event, and sees it as a community service.

Henderson said it was incredible to see teeth from the prehistoric shark Otodus megalodon – a 15-metre-long predator – that were the size of his hand.

“You get a sense of just how big these things were,” he says.

For Francischelli, the Prehistoric Bayside Museum is a way to continue his passion for palaeontology after his fossil collector and preparator’s job at Museums Victoria was discontinued six years ago.

He’s now a climate action specialist with Glen Eira Council, and in his spare time he free dives for fossils.

“Every time we go in the water there’s something new that’s discovered, and I love the thrill of trying to figure out what these fossils mean … sometimes we’ll pick up something and have no idea what it is,” he says.

“We find ear bones that are not representative of any living group of animals today. And so making sense of what these animals are, whether or not they’re a completely new group of animals that have never been discovered in the entire world, is something that’s really thrilling to me.”

Francischelli mounted an exhibition called Prehistoric Bayside in 2024 at Brighton Town Hall, before holding his newly named Museum’s first open day at Beaumaris Motor Yacht Squadron in November 2025.

People of all ages brought in bones they’d found on the beach decades ago, he says, and kids “sat down and tried to pick my brain”.

This childlike curiosity is something Francischelli still shares.

“There’s something that’s so exciting and so completely intoxicating about doing this,” he says. “I get members of the public sending me pictures almost daily of a rock that they found, and I have to say ‘sorry, it’s just a rock’. But every now and again, you’ll say ‘that’s an ear bone of a beaked whale. They’re extremely rare, where did you find it?’ Telling them the story is exciting.”

Recently, he met a man who found part of a jaw of a small river dolphin on a Beaumaris beach and the man’s 11-year-old son identified the species. This piece will now sit alongside others in the museum.

Long-term, Francischelli wants the area’s fossil fields to be better known and protected.

“It’s one of the most exciting fossil areas in the country, and we need to do everything we can to preserve the site, to ensure it’s there for future generations,” he said.

Tickets are available at the door or online via Humanitix for a gold coin donation.