SYDNEY, Jan. 11 (Xinhua) -- A team of Australian and international palaeontologists has discovered thousands of fossilized animals and plants including previously unknown species.
The team's findings, published in Science Advances and revealed on Tuesday, are based on investigations of a site named McGraths Flat in the Central Tablelands region of the state of New South Wales (NSW).
The researchers have been excavating the area during the past three years, discovering the fossils of trapdoor spiders, giant cicadas, wasps, beetles, sawflies, ants, dragonflies, and a variety of fish and rainforest plants.
Matthew McCurry from the Australian Museum and the University of New South Wales (UNSW) said the fossils, which are from the Miocene epoch, provide an important understanding of the history of the Australian continent.
"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," McCurry said.
"The fossils we have found prove that the area was once a temperate, mesic rainforest and that life was rich and abundant here."
McCurry said the invaluable discoveries were made within an iron-rich rock called goethite, which is not usually suitable for the creation of fossils.
The process that turned these organisms into fossils is key to why they are so well preserved, he said, adding that 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.
University of Canberra Associate Professor Michael Frese, who created images of the fossils using a scanning electron microscope, said they revealed "incredibly detailed preservation."
"Using electron microscopy, I can image individual cells of plants and animals and sometimes even very small subcellular structures," Frese said.
The fossils also preserve evidence of interactions between species. For instance, preserving fish stomach contents in the fish means people can figure out what they were eating, he added.
"We have also found examples of pollen preserved on the bodies of insects so we can tell which species were pollinating which plants." ■