title: Breathing room for early animals
abstract: Did an increase in atomospheric oxygen concentration some time during the Neoproterozoic era 1,000 to 543 million years ago, make possible the diversification of multicelluar animals?
authors.affiliation: Botanical Museum, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: A H
authors.initials: AH
authors.lastname: Knoll
mesh_terms: D000818:Animals; D001272:Atmosphere / Q000737:chemistry*; D005075:Biological Evolution; D049872:Bivalvia; D005591:Chemical Fractionation; D005580:Fossils; D019015:Geologic Sediments / Q000032:analysis / Q000737:chemistry / Q000382:microbiology; D006862:Hydrogen Sulfide / Q000737:chemistry*; D010100:Oxygen / Q000032:analysis*; D016999:Sulfur-Reducing Bacteria / Q000378:metabolism*; D013559:Symbiosis
chemical_list: D010100:Oxygen; D006862:Hydrogen Sulfide