A fossil hunt takes Helen O'Neill to the back of beyond.
It's a long, bumpy drive through outback north-west Queensland from Mount Isa to Riversleigh. Plenty of time - as the four-wheel-drive shudders across the bone-dry, dusty, unsealed roads - to mull over whether something that started as a bare bone of an idea really has legs. Or a beak, for that matter.
The idea was this: what would it be like to hunt down creatures such as the Demon Duck of Doom, a long-extinct giant that disappeared from the continent about 50,000 years ago? Or was the notion simply, well, quackers?
The Demon Duck - real name bullockornis - was a monstrous beast. It stood about 2.5 metres tall, couldn't fly and ate like a horse - probably a carnivorous one at that. It got its Tim Burton-esque moniker two years ago when fossilised remains were found at Riversleigh, an inhospitable pile of rocks in which researchers have discovered a bestiary of outlandish beings. Some of them sparked some of the oddest names in paleontology, as well as rewriting Australia's pre-history books. Flesh-eating kangaroos were the least of it.
From Riversleigh came the thingodonatas, or yalkaparidon coheni - a pouched mammal from the Miocene period (about 20 million years ago) that was so peculiar scientists still have no idea what it ate or which creatures it was related to - and the bizarrodonta (yingabalanara richardsoni) a rainforest animal from the same era, which has very strange teeth. So Riversleigh, a 10,000-hectare site in Boodjamulla National Park, had to be the first port of call on my monster hunt. Short of chartering a light plane, though, getting there isn't easy.
The fossil beds are less than 230 kilometres from Mount Isa as the duck flies but the roads here are rough and best negotiated outside the wet season (January to March).
I drop into Mount Isa's visitors' centre to pick up a map and see a Demon Duck foot on display. That I am travelling alone seems to surprise the woman behind the counter.
"You're staying at Adel's Grove?" she asks. Yes, I am. Tours to Riversleigh go from here and it looks relatively convenient.
"Right. There are two ways of getting to Adel's Grove. There's the short way and there's the long way. The short way takes at least four hours. The long way takes at least six.
"You," she stares at me in a meaningful way, "should take the long way. The roads are better and if something does happen there's more likely to be some passing traffic."
The long way it is, then, following a 425-kilometre route that heads north on sealed roads, turns west at the Burke and Wills Roadhouse and changes direction again at Gregory Downs. If you miss this turn, as I did, you'll keep heading towards the Gulf of Carpentaria.
By the time I return to Gregory Downs, it is dusk and I've been driving for about nine hours. I drive the final leg in pitch darkness. Adel's Grove cannot come soon enough. A sprawling oasis at Lawn Hill Creek, it has a river, huge trees, manicured lawns, permanent tents and cabins and a restaurant. Best of all is the warm reception. Within minutes of arriving, saucer-eyed and exhausted, a large glass of red wine is pressed into my hand and I'm fed supper. The following morning, 18 of us board a bus for the tour of Riversleigh D-Site, the only one of more than 200 fossil localities open to the public. The guide is Ron Low Mow, one of the owners, and he gives a running commentary on the flora, fauna and local history during the hour-long rattle-ride before suddenly stopping the vehicle at a cattle grid. This, Mow says, may be more than 200 kilometres from the centre of Mount Isa but the city itself begins here.
D-Site doesn't look much at first. It's a rocky hill, dotted with bushes and limestone outcrops. At its base is a cave-like construction that looks as though Fred Flintstone should be living in it. Inside, the cave walls are painted with some of Riversleigh's monsters and the people who discovered them. Mow isn't impressed.
"I gave up asking them to remove that," he says, pointing at a depiction of a hammer and chisel. "You'll only damage the bone if you try to get it out of the rock like that."
In fact they blast into the past very carefully, he explains. "They've got it down to a fine art."
He begins walking along the path that leads up the hill. Twenty-five million years ago this was where the rainforest met the sea, he says.
"Where we're standing is about 30-40 feet [nine to 12 metres] below that rainforest. Erosion has brought us down to here. This was a watering area, a lagoon or lake - rich with calcium. Animals came here, died here, their bones settled in the calcium and they petrified here."
He stops at rocks beside the path, pointing out bones still embedded inside them. There's a horned freshwater turtle, an ancient crocodile and - yes - the Demon Duck.
Researchers visit for about 10 days every year and various dig-sites have revealed every kind of native creature now alive in Australia.
"Riversleigh," says Mow, "gives science a window into evolution from 15,000 years to 25 million years. It is very special."
In 1994, Riversleigh became part of Australia's only World Heritage Fossil Mammal Site, in tandem with another place also considered one of the top 10 fossil sites in the world - Naracoorte in South Australia.
More than 2000 kilometres south of Riversleigh, Naracoorte couldn't be more different. Riversleigh's treasures lie largely above ground; finding those at Naracoorte involves diving into the heart of darkness.
The South Australian site is blissfully easy to get to; a pleasant one-hour drive from Mount Gambier (the nearest airport) through the Coonawarra wine district on a road that meanders past lush, rural properties and vineyards crying out for a side trip.
The fossil sites are 10 kilometres south of Naracoorte, a cute country town featuring, among other things, a mini jumbuk factory. The turn-off is marked by huge metal sculptures of dinosaurs at the entrance and the car park is watched over by an elephant-sized model of the largest marsupial ever to live: diprotodon australis - the giant wombat.
Eons past, waves lapped this land. The waters gradually retreated and about 700,000 years ago caves-ins began to open up the catacombs below. They turned into mass graveyards for long-lost creatures that fell in and were unable to scramble out. The skeleton haul to date ranges from ancient birds and prehistoric reptiles to dozens of species of megafauna.
Only a handful of the 26 caves found so far in this 600-hectare patch are open to the public. Some are dead-ends, terrifyingly convoluted and chillingly cold - the temperature can dive to less than 10 degrees - and a number remain sealed, still unexplored after hundreds of thousands of years. Others are so opened up by roof collapses that impromptu gardens have sprung up within them.
Like Riversleigh, the best way through this labyrinth is via guided tour and the most exciting of these is the World Heritage Tour. This behind-the-scenes trek begins in the Victoria Fossil Cave, more than 4000 metres of subtly lit, fantastical chambers in which stalactites and stalagmites create breathtaking rock formations.
This cave contains six known fossil deposits and a sign blocking access into what looks like a compact tunnel that says "Researchers Only". The guide removes the sign and then it's down on hands and knees into a dig absolutely groaning with bones, where ladders descend into pits.
"Riversleigh opened a gigantic window in time back 25 million years," says cave manager Steven Bourne, who is taking this tour. "Naracoorte sheds light on more recent times and, possibly, on what may happen in the future, thanks to the relics of ancient plants and layered records of extinctions as the eons have gone by.
"Naracoorte has the last gasp, when all these animals became extinct somewhere in the last 50,000 years.
"Riversleigh is the rise of the megafauna. We are its demise."
The hunt ends at the Wonambi Fossil Centre. Here, in a walk-through reconstruction of pre-historic Naracoorte, is a snapshot of an ancient rainforest and full-sized, animatronic megafauna. The creatures move and cry out to each other, for all the world as though the events about to overtake them never happened.
They are bizarre and outlandish but they belong here.
And perhaps they're not so very monstrous after all.
Riversleigh, Queensland The quickest way is to charter a light plane to Adel's Grove. Otherwise, fly to Mount Isa and drive - the shortest road route takes about five hours.
Naracoorte, South Australia Fly to Mount Gambier, then make the one-hour drive. From Adelaide, it's a four-hour drive.
Tours to Riversleigh D-Site are $65 a person, departing from Adel's Grove. Phone (07) 4748 5502 or see www.adelsgrove.com.au. The World Heritage Tour at Naracoorte costs $210 a group for four to six people. Phone (08) 8762 2340 or see www.naracoortecaves.sa .gov.au.