The oldest known fossils on earth are stromatolites (blue-green algal mats) and microbial body fossils that around 3.5 billion years old. Among the oldest macro-scale body fossils are these from the Negaunee Iron Formation from Michigan’s Upper Pennisula. These are among the earliest eukaryotes found in the fossil record, and date to ~2.1 billion years old.

The Science Museum’s paleontology collection literally spans the history of life on earth – there is virtually no better demonstration of this than our collection of Grypania spiralis. Imagine a world where these tiny filaments are among the most complex creatures around.
– Kristi Curry Rogers, Curator of Paleontology