||Lake Richmond, in Western Australia, is one of the few lakes in the world containing thrombolites, critically endangered microbial structures. The thrombolite-building microorganisms resemble the earliest forms of life on Earth. These organisms were the only known form of life on Earth from 3.5 billion to 650 million years ago. They dominated the clear, shallow seas of the period.
Thrombolites are also present in Kelly Lake (British Columbia, Canada) and Lakes Cooloongup, Walyungup and Clifton in Australia.