Lost world of prehistoric animals unearthed in Australian outback’s ‘dead heart’


DARLINGHURST, Australia — A “lost world” of prehistoric rainforest animals is reshaping how scientists take a look at the Australian outback. Researchers from the Australian Museum and University of New South Wales have found a fossilized forest that comprises hundreds of pristine specimens, together with bugs, spiders, fish, and birds.

Some of the fossils even had remnants of their final meal nonetheless in their stomachs. Others had been coated in pollen, revealing the flowers they consumed. This unbelievable array of creatures dates again between 11 and 16 million years, opening a window in time to what was as soon as a thriving panorama.

Rewriting Australia’s local weather historical past

Australia is the driest inhabited continent, with arid or semi-arid land overlaying 70 % of the nation. The graveyard, named McGraths Flat, is one of an important discoveries of its type. Study authors add that their findings reveal the historic affect of local weather change and should have implications for the planet at the moment.

Dr. McCurry with historical fossils discovered in Australia. (Image credit score: University of New South Wales)

“The fossils we have found prove that the area was once a temperate, mesic rainforest and that life was rich and abundant here in the Central Tablelands, NSW (New South Wales),” says lead writer and paleontologist Dr. Matthew McCurry in a media launch. “Many of the fossils that we are finding are new to science and include trapdoor spiders, giant cicadas, wasps and a variety of fish.”

Cicadas are among the many planet’s oldest bugs. The massive, winged bugs with bulbous eyes spend most of their time in the soil. They feed on tree roots. While they keep underground, the bugs should not hibernating. They molt 4 instances earlier than ever attending to the floor.

“Until now it has been difficult to tell what these ancient ecosystems were like, but the level of preservation at this new fossil site means that even small fragile organisms like insects turned into well-preserved fossils,” Dr. McCurry says.

Looking at fossils on a mobile stage

Researchers add the examine reveals there was as soon as life in what’s now the “dead heart” of Australia. The fossil website is situated in Central Tablelands, New South Wales, close to the nineteenth century gold rush city of Gulgong. Scientists classify this space as a “Lagerstatte” — German for fossils of distinctive high quality that generally embrace mushy tissue.

An expedition of scientists has been secretly excavating it for the final three years. They additionally recovered stays of beetles, flies, algae, fungi, and different dwelling issues from a heat interval in historical past referred to as the Miocene Epoch.

“Using electron microscopy, I can image individual cells of plants and animals and sometimes even very small subcellular structures,” co-author Professor Michael Frese from the University of Canberra explains.

“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.”

Feather fossil
Ancient feather from new Australian fossil website. (Image credit score: University of New South Wales)

Dr. Frese was capable of determine pores and skin cells referred to as melanosomes, tiny packages of pigment inside feathers and hair.

“The discovery of melanosomes (subcellular organelles that store the melanin pigment) allows us to reconstruct the color pattern of birds and fishes that once lived at McGraths Flat. Interestingly, the color itself is not preserved, but by comparing the size, shape and stacking pattern of the melanosomes in our fossils with melanosomes in extant specimens, we can often reconstruct color and/or color patterns,” Frese provides.

McGraths Flat already drying out thousands and thousands of years in the past?

The fossils had been discovered inside an iron-rich rock referred to as “goethite,” which isn’t often a dependable supply of distinctive fossils.

“We think that the process that turned these organisms into fossils is key to why they are so well preserved. Our analyses suggest that 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,” Dr. McCurry continues.

A billabong – an Aboriginal phrase – is a relaxed, remoted stretch of water left behind when a river adjustments its course. The crops and animals described in the journal Science Advances are much like these discovered in rainforests of northern Australia. However, there are indicators the ecosystem at McGraths Flat was already starting to dry throughout this era.

“The pollen we found in the sediment suggests that there might have been drier habitats surrounding the wetter rainforest, indicating a change to drier conditions,” McCurry says.

Australia’s wild experience via historical past

Study authors imagine the Miocene Epoch was a time of immense change. The Australian continent separated from Antarctica and South America and began drifting northwards. When the Miocene started 23 million years in the past, there was huge richness of plant and animal life. About 9 million years later, nevertheless, there was an abrupt change in local weather and Australia started turning into huge shrublands and deserts. The sheer scale and selection of fossils supplies unprecedented insights into the land’s mysterious previous.

“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,” provides Professor David Cantrill, govt director of science at Royal Botanic Gardens Victoria.

“Australia is the most unique continent biologically, and 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,” concludes Prof. Kristofer Helgen, chief scientist on the Australian Museum, New South Wales.

South West News Service author Mark Waghorn contributed to this report.