Miocene Fossils from McGraths Flat, Australia

Amazing fossils from 15 million-year-old deposits in Australia, preserved in iron-rich rocks. 

The exquisite details include feathers, tiny parasites riding on larger organisms, even pollen grains. 

This spot seems to have been an Oxbow Lake in a rain forest ecosystem. As to how this happened, the excavators are not sure:

The secret to the fossils’ preservation is up for debate, but McCurry thinks it would have happened over hundreds of years rather than in a sudden event.

Iron-rich water, maybe from nearby outcrops, could have flowed into a shallow billabong, periodically deoxygenating the water, killing the organisms or encasing flora and fauna in sediment that turns into the rocks found in the field.

Close-up of the sawfly above, showing its head, and a microscopic image showing the pollen grains still visible there. Astonishing.

A larval mussel riding on the fin of a fish as a parasite.

Tiny flowers.

Longhorn Beetle. Original publication, long story at the NY Times.