title: Microfossils of the Early Archean Apex chert:  new evidence of the antiquity of life.
abstract: Eleven taxa (including eight heretofore undescribed species) of cellularly preserved filamentous microbes, among the oldest fossils known, have been discovered in a bedded chert unit of the Early Archean Apex Basalt of northwestern Western Australia. This prokaryotic assemblage establishes that trichomic cyanobacterium-like microorganisms were extant and morphologically diverse at least as early as approximately 3465 million years ago and suggests that oxygen-producing photoautotrophy may have already evolved by this early stage in biotic history.
authors.affiliation: Department of Earth and Space Sciences, University of California, Los Angeles 90024, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Schopf
mesh_terms: D001419:Bacteria; D005075:Biological Evolution; D000458:Cyanobacteria; D004783:Environmental Microbiology; D005580:Fossils; D019015:Geologic Sediments / Q000032:analysis* / Q000382:microbiology*; D010163:Paleontology; D011387:Prokaryotic Cells / Q000145:classification*; D014904:Western Australia