title: How old are the eukaryotes?
abstract: Evidence from Precambrian sediments appears to indicate that nucleated (eukaryotic) organisms had become well established and relatively diverse about 850 +/- 100 million years ago and that eukaryotes were probably extant, and may have first appeared, as early as 1400 +/- 100 million years ago.
authors.forename: J W
authors.initials: JW
authors.lastname: Schopf
authors.forename: D Z
authors.initials: DZ
authors.lastname: Oehler