Earliest documentation of fossil ciliate protozoans

The world’s earliest known fossil ciliate protozoans were formally documented in 2007. These ‘hairy’ microscopic single-celled organisms, characterised by tiny hair-like structures known as cilia on their external surface, were discovered within the Doushantuo Formation – a fossil-rich sedimentary deposit in China’s Guizhou Province, dating back approximately 580 million years to the Ediacaran Period.