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1,800 mya: Oldest eukaryote fossils
Though eukaryotes are thought to have evolved much earlier, the oldest definitive fossils date to . Acritarchs are probably single-celled in a resting stage of their life cycle that have grown tough outer coats. They are spherical in shape and float at or near the surface of the .
1,200 mya: True algae
The oldest algae fossil dates to 1,200 mya. At this time, biological diversity increases greatly, with algae, , , and diverging from their common eukaryote ancestors.
900 mya: Soft-bodied animals
The oldest fossil evidence of multicellular animals, or metazoans, are burrows that suggest smooth, creatures live or more. Found in rocks in China, Canada, India, and elsewhere, the imprints of these creatures reveal little else besides their basic shapes.