title: Fossil evidence of Archaean life.
abstract: Evidence for the existence of life during the Archaean segment of Earth history (more than 2500 Myr ago) is summarized. Data are presented for 48 Archaean deposits reported to contain biogenic stromatolites, for 14 such units reported to contain 40 morphotypes of putative microfossils, and for 13 especially ancient, 3200-3500 Myr old geologic units for which available organic geochemical data are also summarized. These compilations support the view that life's existence dates from more than or equal to 3500 Myr ago.
authors.affiliation: University of California, Department of Earth and Space Sciences, Institute of Geophysics and Planetary Physics (Center for the Study of Evolution and the Origin of Life), Los Angeles, CA 90095, USA. schopf@ess.ucla.edu
authors.forename: J William
authors.initials: JW
authors.lastname: Schopf
mesh_terms: D000458:Cyanobacteria / Q000254:growth & development; D005580:Fossils; D019015:Geologic Sediments / Q000382:microbiology*; D010163:Paleontology