Lost world of prehistoric animals unearthed in Australian outback

By Mark Waghorn via SWNS

A 'lost world' of prehistoric rainforest animals has been unearthed... in the Australian outback.

The fossilized forest contains thousands of pristine specimens - ranging from insects, spiders and fish to a bird feather.

Some even had remnants of their last meal in their stomach. Others were covered in pollen - revealing the flowers they fed on.

The incredible array of creatures are between 11 and 16 million years old - opening a window into a once verdant landscape.

Average global temperatures are thought to have been between 3C and 7C higher than they are now, and ice largely disappeared from the poles.

Australia is the driest inhabited continent. Arid or semi-arid land covers 70 percent.

The graveyard, named McGraths Flat, is one of the most important discoveries of its kind. It has implications for climate change today.

Lead author Dr. Matthew McCurry, a palaeontologist at the University of New South Wales, said: "The fossils we have found prove the area was once a temperate, mesic rainforest and that life was rich and abundant.

"Many of the fossils we are finding are new to science and include trapdoor spiders, giant cicadas, wasps and a variety of fish."

Cicadas are among the planet's longest-lived insects. The large, winged insects with bulbous eyes spend most of their time in the soil.

They feed on tree roots. While they stay underground, the bugs are not hibernating. They moult four times before ever getting to the surface.

Dr. McCurry said: "Until now it has been difficult to tell what these ancient ecosystems were like.

"But the level of preservation at means even small fragile organisms like insects turned into well-preserved fossils."

He added: "It shows there was once life in the 'dead' heart of Australia."

The site is located in Central Tablelands, New South Wales, near the 19th-century gold rush town of Gulgong.

It has been classified as a 'Lagerstatte' - German for fossils of exceptional quality that sometimes include soft tissue.

An expedition of scientists has been secretly excavating it for the last three years.

They also recovered remains of beetles, flies, algae, fungi and other living things from a warm period known as the Miocene Epoch.

The study in Science Advances sheds fresh light on the history of the world's biggest 'island' - and smallest continent.

Co-author Professor Michael Frese, of the University of Canberra, used powerful scanners to reveal the fossils' incredibly detailed preservation.

He said: "Using electron microscopy, I can image individual cells of plants and animals and sometimes even very small subcellular structures.

"The fossils also preserve evidence of interactions between species. For instance, we have fish stomach contents preserved in the fish, meaning that we can figure out what they were eating.

"We have also found examples of pollen preserved on the bodies of insects so we can tell which species were pollinating which plants."

Dr. Frese was able to identify skin cells known as melanosomes, tiny packages of pigment inside feathers and hair.

He explained: "It allows us to reconstruct the colour pattern of birds and fishes that once lived at McGraths Flat. Interestingly, the colour itself is not preserved.

"But by comparing the size, shape and stacking pattern of the melanosomes in our fossils with melanosomes in living specimens, we can often reconstruct colour and patterns."

The fossils were found within an iron-rich rock called 'goethite' - not usually thought of as a source of exceptional fossils.

Dr. McCurry said: "We think the process that turned these organisms into fossils is key to why they are so well preserved.

"Our analyses suggest the fossils formed when iron-rich groundwaters drained into a billabong, and that a precipitation of iron minerals encased organisms that were living in or fell into the water."

A billabong - an Aboriginal word - is a calm, isolated stretch of water left behind when a river changes its course.

The plants and animals described in Science Advances are similar to those found in rainforests of northern Australia.

But there were signs the ecosystem at McGraths Flat was beginning to dry.

Dr. McCurry said: "The pollen we found in the sediment suggests there might have been drier habitats surrounding the wetter rainforest, indicating a change to drier conditions."

It was a time of immense change. The Australian continent had separated from Antarctica and South America and was drifting northwards.

When the Miocene began 23 million years ago there was enormous richness of plant and animal life.

But about nine million years later there was an abrupt change in climate - and Australia began turning into vast shrublands and deserts.

The sheer scale and variety of fossils provide unprecedented insights into the land's enigmatic past.

Professor David Cantrill, executive director of science at Royal Botanic Gardens Victoria said: "The McGraths Flat plant fossils give us a window into the vegetation and ecosystems of a warmer world, one that we are likely to experience in the future.

"The preservation of the plant fossils is unique and provides important insights into a time period for which the fossil record in Australia is rather poor."

Prof Kristofer Helgen, chief scientist at the Australian Museum, New South Wales, said the site brings to life a picture of the outback we can barely believe existed.

He said: "Australia is the most unique continent biologically. This site is extremely valuable in what it tells us about the evolutionary history of this part of the world.

"It provides further evidence of changing climates and helps fill the gaps in our knowledge of that time and region."

The fieldwork was funded by a descendant of Robert Etheridge, an English palaeontologist who went to Australia in 1866. He was made Curator of the Museum in 1895.