もっと詳しく

Slashdot reader BoogieChile writes:
Details of an important new fossil site has just been published in the first Science Advances journal for the new year. McGraths Flat, in New South Wales, Australia, was once the location of this oxbow lake in a mesic rainforest. Today, superb examples of fossilised animals and plants from the Miocene epoch have been recovered, showing incredible detail, including melanosomes preserved in feathers of birds and the eyes of fossilised fish

“The discovery of melanosomes — subcellular organelles that store the melanin pigment — allows us to reconstruct the colour pattern of birds and fishes that once lived at McGraths Flat,” said Dr Michael Frese of the University of Canberra, one of the team’s leaders. “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 extant specimens, we can often reconstruct colour and/or colour patterns.

“Over the last three years a team of researchers has been secretly excavating the site, discovering thousands of specimens including rainforest plants, insects, spiders, fish and a bird feather,” announced the 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,” said UNSW Sydney palaeontologist Dr Matthew McCurry [one of the team’s leaders]. “Many of the fossils that we are finding are new to science and include trapdoor spiders, giant cicadas, wasps and a variety of fish.

“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.”

Associate Professor Michael Frese, who imaged the fossils using stacking microphotography and a scanning electron microscope, said that the fossils from McGraths Flat show an incredibly detailed preservation. “Using electron microscopy, I can image individual cells of plants and animals and sometimes even very small subcellular structures,” Dr Frese said. “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.”

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