Striking fossils of spiders, insects and fish tell Australia’s origin story

Fossil spiders, cicadas, wasps, plants and fish date from 11 million to 16 million years ago during the Miocene epoch, painting a vivid picture of Australia’s once-abundant rainforest ecosystems.

“This is an extremely important fossil site,” said Matthew McCurry, a paleontologist at the Australian Museums Research Institute. It has everything we’d expect, exceptionally well-preserved fossils we don’t know much about. Huh.” were the authors of a study from the site published Friday in the journal Science Advances.

“The Miocene was the point in time when most of the modern Australian environment was established, and so this fossil site is really the origin story of Australia.”

During the Miocene, less rainfall caused rainforests around the world to shrink, leaving the landscape drier, the study said.

The site, named McGrath Flat and located in the Central Tablelands near the city of Gulgong, was discovered by a local farmer who found the fossilized leaves in one of his fields, McCurry said.

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

accumulation of well-preserved fossils

“Fossils are amazingly beautiful to look at, and using a microscope we can see the details of the surfaces of fossils that are surprisingly well preserved,” he said via email.

“Organelle-like features can be observed within individual cells and even cells. This level of detail allows us to say more about these ecosystems.”

For example, melanosomes discovered in a fossil feather mean that scientists can determine the color of the feather. In this case, they believe it was dark brown to black in color.

Paleontologist Matthew McCurry (above), of the Australian Museum Research Institute, and his colleagues visited the fossil site seven times.

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

When iron-rich groundwater flowed into a billabong, or watering hole, plants and organisms became fossilized.

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

“It’s a very beautiful specimen.”