Amazing fossils of spiders and fish show Australia’s origins

Australia’s deserts and arid bushes weren’t always like this, according to a newly discovered paleontological site with extraordinarily well preserved fossils in New South Wales.

Spiders, cicadas, wasps, fossilized plants and fish, dating between 11 million and 16 million years ago during the Miocene era, are painting a vivid picture of what was once Australia’s abundant rainforest ecosystems.

“It is an extremely important fossil reserve. It’s got everything we’d hoped for, exceptionally well-preserved fossils from a time we don’t know much about,” said Matthew McCurry, a paleontologist at the Australian Museum and Research Institute who also authored the site study, published in Science Advances this Friday. market.

“The Miocene era was the time period when most of modern Australia’s environments were established, so this fossil site is really Australia’s origin story.”

During the Miocene era, reduced rainfall caused a decline in tropical forests around the world, leading to increasingly arid landscapes, the study reports.

The reserve, named McGrath’s Plain and located in the Central Highlands near the city of Gulgong, was discovered by a local farmer who found fossilized leaves in one of its fields, says McCurry.

McCurry and his colleagues visited and excavated the site seven times.

Well-preserved fossil hideout

“Fossils are incredibly beautiful to look at, and using a microscope, we can look at the details of their surfaces that are also incredibly well preserved,” McCurry wrote in an email.

“Features like individual cells and even organelles within cells can be seen. This level of detail allows us to talk much more about what ecosystems were like.”

For example, melanosomes found in a fossilized feather mean that scientists can determine its color. In this case, they believe in a shade of dark brown to black.

Paleontologist Matthew McCurry (photo), from the Australian Museum and Research Institute, along with his colleagues, have visited the paleontological site seven times.

The site, formed of iron-rich rock, was destined to be considered a Lagerstätte, said McCurry, a German term that paleontologists use to describe an exceptional site with many perfectly preserved fossils.

Plants and creatures were fossilized when iron-rich groundwater was contained in a lake.

McCurry said his favorite fossil was a type of spider, which was the best preserved spider fossil ever found in Australia.

“It is an extremely beautiful specimen.”