Amazing spider and fish fossils tell the story of Australia

(CNN) – The deserts and arid lands of Australia have not always been this way, according to a newly discovered and well-preserved fossil site in New South Wales. Fossilized spiders, cicadas, wasps, plants and fish, dating between 11 million and 16 million years ago during the Miocene Epoch, paint a vivid picture of the rainforest ecosystems that were once abundant in Australia.

Matthew McCurry, a paleontologist at Australian Museum Research Institutewho wrote a study for the site that was published in the journal Science Advances on Friday.

“The Miocene was the time when most of the modern Australian environments were created, so this fossil site is really the origin story of Australia.”

During the Miocene, reduced rainfall caused rainforests around the world to shrink, resulting in increasingly arid landscapes, according to the study.

McCurry said the site, called McGraths Flat and located in the middle of the Tablelands, near the city of Gulgong, was discovered by a local farmer, who found petrified leaves in one of his fields.
McCurry and his colleagues visited and excavated the site seven times.

A cache of well-preserved fossils

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

“The fossils are incredibly beautiful when you look at them and with a microscope we can see the details of the incredibly well-preserved fossil surfaces,” he said by email.

“You can see features like individual cells and even organelles within cells. This level of detail allows us to tell a lot about what these ecosystems look like.”

For example, the discovery of melanosomes in fossilized feathers means that scientists can determine the color of the feathers. In this case, they think it is dark brown to black.

McCurry said the site, made up of iron-rich rocks, was meant to be thought of as Lagerstätte, a German term used by paleontologists to describe an exceptional site with many well-preserved fossils.

Plants and creatures became petrified when iron-rich groundwater was drained into a water well.

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

“It’s a very beautiful specimen.”