A 3.4 BILLION YEARS OLD STROMATOLITE, ONE OF THE WORLD'S MOST ANCIENT FOSSILS

A 3.4 BILLION YEARS OLD STROMATOLITE, ONE OF THE WORLD'S MOST ANCIENT FOSSILS

a slice of the best preserved ancient macrofossil (i.e. one large enough to be visible without a microscope): a stromatolite from the remote Strelley Pool locality in Western Australia, on a perspex stand,

16cm x 10 cm (138 g), polished on one side

Stromatolites are solid mounds comprised of layers of calcium carbonate and trapped sediment formed by colonies of blue-green algae (primitive single-celled organisms). Blue-green algae are the earliest known form of life on Earth and have been tremendously important in shaping the course of evolution and ecological change throughout our planet's history. The oxygen atmosphere that we depend on was generated by blue-green algae photosynthesizing during the remote Archaean and Proterozoic Eras. Before that time, the atmosphere had a very different chemistry and was toxic to life as we know it today. The famous Strelley Pool stromatolites formed a reef around an ancient coastline. They have been the subject of dozens of scientific studies and microfossils of the blue-green algae which built them have been found preserved within them. Specimens of these stromatolites are now difficult to obtain due to restrictions on their export imposed by the Australian government.