Tim Wagstaff knew that fossilised footprints of a raptor-like dinosaur had been found near Skenes Creek, on Victoria's Great Ocean Road, back in the 1980s.
But he was out recently with his wife, Kate, searching for his own prehistoric remnants in the same area, when he discovered what might be the prints of a new, unknown dinosaur.
Mr Wagstaff spotted a type of marine rock shelf that he recognised as being similar to another trace-fossil site, but it was Ms Wagstaff who saw the footprints first.
"Kate's got better eyesight than me, so she actually found the first couple of footprints and from there it just snowballed," he said.
The Wagstaffs discovered many prints of several sizes etched into the rock, which they said looked like a "three-footed toe very similar to a modern bird, like an emu's foot".
"It's a trackway with dinosaur footprints that stretches some 25 metres across a rock shelf, it'd be two metres wide," Mr Wagstaff said.
On the first day of searching the couple found an astonishing 60 footprints, but as they returned to the site over the next few days, they discovered more and more.
Since their initial find, the Wagstaffs have been pulled into an adventure of discovery that most fossil enthusiasts can only dream of, working with palaeontologists across Australia to document and further investigate their find.
The pair photographed the footprints and initially sent them to Museums Victoria for further study, but it wasn't until those photographs reached Anthony Romilio, who studies dinosaur footprints at the University of Queensland, that things got really exciting.
"Tim and Kate Wagstaff are actually at the site and they're documenting it remotely for me," Dr Romilio said.
"They are taking a series of photos of each track and each trackway and then send that to me. I make a 3D model of it and convert it into a format that is appropriate for documentation to the scientific community."
Kate Wagstaff is relishing watching her husband, a carpenter and painter by trade, revelling in the flurry of emails, information and photographs going back and forth between him and palaeontologists.
"He's on a huge high," she said.
Even though it's his day job, Dr Romilio is equally excited.
"I share with with Tim and Kate in their enthusiasm, because they're just so excited to be there and finding the next thing and the next thing," he said.
140 footprints and counting
Dr Romilio is one of Australia's few experts in palaeoichnology — the study of dinosaur footprints — and he has enthusiastically confirmed the footprints are "absolutely" made by dinosaurs.
Not only that, but there are many more footprints than first thought, and some belong to an unrecognisable dinosaur, maybe a newly discovered species.
"The tally so far has reached the 140 dinosaur footprints at their particular site," Dr Romilio said.
He said to have so many prints from a variety of species at one locality was rare and exciting in comparison to nearby sites that contained only a dozen footprints.
It was too early, however, to know the details about which species might have left these historic marks beyond guesswork, he added.
"We can only surmise very broadly, we can't narrow it down to particular species unless we have the dinosaur at the end of the trackway.
"Some of the small tracks would have been track-makers about the size of a chicken, whereas some would have had legs like a really tall basketballer, say 120-centimetre-long legs."
Dr Romilio is also quietly thrilled about the possibility held within some mystery prints that were made by an unknown carnivorous dinosaur.
Further analysis would be required to determine if this was a new species or something that might resemble a dinosaur from another other part of the world, he said.
But more than one palaeontologist to have seen photos of the prints have mentioned the name of a particularly fierce predator whose fossilised bones were found in the Cape Otway region — the Australovenator.
Prime dinosaur territory
Tim Ziegler, collections manager of vertebrate palaeontology at Museums Victoria, said the newly discovered trackway was located in "prime dinosaur territory" that was known to be the home of a "fearsome predator".
"If you want to know what was the biggest and most fearsome predator in dinosaur age in Victoria was, well, its remains were found around Cape Otway," Mr Ziegler said.
Named Australovenator ("southern hunter") because it was a carnivore only found in Australia, it was a tall, meat-eating theropod that looked much more like a T-rex than its emu-like prints might suggest to the amateur eye.
"From Apollo Bay to further west around Cape Otway, there are many examples of what we call localities; places along the coast where the rocks are eroding away to expose traces of that dinosaur-aged environment.
"Sometimes that is trackways, sometimes it's actual dinosaur bones and teeth."
Mr Ziegler said the geomorphological process that preserved these trackways enabled us to now tell the story of dinosaurs moving across a vastly different landscape 120 million years ago, possibly on a hunt.
"Those rocks that make the cliffs there, these were layers of mud and sand and sediment along the banks of enormous braided rivers that were running between, believe it or not, Australia and Antarctica at the time.
"So this is where these dinosaurs were walking, either on their own in groups, maybe even following their prey.
"Their depressions, that pressure is left behind, the sediment is quickly covered by another layer and then, 108 million years later, you've got something going on."
Back at the University of Queensland, Dr Romilio says he hopes to include Tim and Kate Wagstaff's find into a trackway study he was publishing, a paper which now will likely include their names as co-authors.
