Coming soon Spider, Tropical plants, a fish, a bird feather. It is the largest collection of species discovered by scientists in Australia’s Southeast. According to their study, published this month, species that have been extinct for more than 10 million years In review Scientific advances.
Their tracks appeared at the site, identified in 2017 near the New South Wales town of kulgong, and researchers have been secretly excavating for the past three years. These excavations have made it possible to describe the place as a”Lagerstätte“, The German term for a sedimentary deposit with many fossils of good quality.
The site is quite exceptional because it has a rich diversity of fossils and belongs to some smaller and more delicate species. They were preserved in an iron-rich rock called goethite, which is not generally considered a good source of remains.
“Our analyses suggest that fossils formed when iron-rich groundwater flowed into an average, and that precipitation of iron minerals linked organisms that lived inside or fell into the water“, Explained In a press release Dr Matthew McGarry, Australian Museum paleontologist and first author of the report.
Species unknown to science
Some of these systems were previously unknown to experts. “Many of the images we see are new to science. It includes burrowing spiders, giant cicadas, Wasps and a variety of fish“, He continued. All of them, examined in detail with different techniques, showed a significant security state.
“Using electron microscopy, I can observe the individual cells of plants and animals, and sometimes even very small supporting structures“, Confirmed Dr Michael freeze from the University of Canberra and co-author of the study. Rare, fossils have also preserved traces of interactions between species.
“For example, we have preserved stomach contents in fish, which means we can determine what they eat. We also found examples of pollen preserved in insect bodies so we could tell which species pollinated which plants“, He added.
According to their study, the samples were between 11 and 16 million years ago, which corresponds to the Miocene period when Australia experienced significant changes. Previous research has actually shown that the island-continent became increasingly dry in the second half of the Miocene, gradually covering itself with deserts.
A unique insight into past ecosystems
Hence the importance of the new site identified in New South Wales: it provides a remarkable overview of what the region’s ecosystems were like at the time. “The fossils we found prove that the area was once a Mesic wet forest and that life was abundant on rich and central plateaus“, Supported Dr. McGarry.
“Now we know how diverse these ecosystems were, which species lived in them and how they interacted“, He clarified To Direct science. Thanks to the observation of the samples, the researchers were even able to find sub-cellular structures that provide clues about the color of extinct birds and fish.
The image depicted by these fossils is similar to those found in the humid forests of northern Australia. However, signs were found in the study, especially in traces of pollen preserved in sediments, and this same ecosystem had already begun to dry up at that time.
“Australia is a very biologically unique continent and this site is very valuable in telling us about the evolutionary history of this part of the world”, Confirmed B.R. Kristofer Helgen, director of the research institute at the Australian Museum. “It helps to fill in the gaps in our knowledge of this period and region“.
However, the work has only begun for Dr McGarry and his colleagues, who have not yet worked to describe and name all the species discovered on the McGrath’s Flat site, and is therefore called in reference to the one who discovered it in 2017 by Nigel McGrath.
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