For Paul Tierney, the tooth is out there – it just may take some time to find.
The research assistant spends his days in a decidedly low-tech laboratory at the Queensland Museum's Hendra annexe, sorting through soil from a fossil-rich Geebung construction site.
With hoses, sinks, benches, metal racks and plastic containers, it looks like a set from Breaking Bad.
But Mr Tierney is not interested in amphetamines. He's searching for amphibians. Or marsupials.
“One tooth could rewrite the history books,” Mr Tierney said, sifting through a pile of oil shale.
“If we do find evidence of mammals in the Geebung area it will be the equal second-oldest evidence in Australia... if we find an amphibian it'll be the oldest in the country.”
The story of how tiny fossils could be such a big deal began in July 2013, when workers drilling bridge support holes along Robinson Road for a rail overpass spotted interesting objects in the spoil.
They called in Queensland Museum experts, who jumped at the chance to examine material from a site that was a freshwater lake and swampland about 50 million years ago.
Head of Geosciences Andrew Rozefelds said discoveries in the Geebung spoil would hopefully help fill the knowledge gap about what happened after the dinosaurs and before the era of Australia's mega-fauna.
“The importance of Geebung is the opportunity it provides to look for evidence of early marsupials and birds,” he said.
“The fossil record for these animals is very poor at the moment in Australia.”
Dr Rozefelds said the early finds – a crocodile vertebrae, snails and fish fossils – were media friendly, but the work since then has been on a much smaller and painstakingly slow scale.
He said that's why the museum hadn't yet been able to take up generous offers from schools and members of the public to help filter and sort the material.
“We've had to develop new processes for breaking down the oil shale, as fossils are usually found in limestone,” Dr Rozefelds said.
Mr Tierney's work involves soaking chunks of oil shale in peroxide for months at a time, then sifting the material through sieves just 2mm, 1mm and 0.5mm thick looking for fossils.
He paused during a sieve to point out a tiny black line in a piece of grey rock. Less than 2mm long, it looks like a chin hair whisked off during a morning shave. But it is in fact a fish bone.
“That's huge,” he said.
Most of what the scientists find is fish bone from the freshwater fish that populated the lake, but Dr Rozefelds said they're searching for anything white, which could be bone or more importantly, teeth, which are important in identification.
Mr Tierney said they already had what they believed to be a thigh bone from a frog, but needed further proof.
Any tooth found would need to be processed by an electron scanning microscope and compared to already recorded finds to trace its species of origin.
“If we find one that's two millimetres or larger, wacko, it'll be terrific,” he said.
“You'll hear us squealing from here.”
Some of the early finds from the Geebung spoil are on display in the Lost Creatures dinosaur exhibit at the Queensland Museum at South Bank.
Dr Rozefelds said his team hoped to deliver more research outcomes for that exhibition, but the Geebung project was just one of many fossil excavations underway in Queensland.
“It's a very exciting time, but we have limited resources,” Dr Rozefelds said.
“You could say we're looking for a needle in a very, very, very large haystack.”