• Publications
  • Influence
Megascopic eukaryotic algae from the 2.1-billion-year-old negaunee iron-formation, Michigan.
Hundreds of specimens of spirally coiled, megascopic, carbonaceous fossils resembling Grypania spiralis (Walcott), have been found in the 2.1-billion-year-old Negaunee Iron-Formation at the Empire Mine, near Marquette, Michigan, placing the origin of organelle-bearing eukaryotic cells prior to 2. Expand
Two or four Neoproterozoic glaciations
A thick Neoproterozoic carbonate and glaciogenic succession of the southern Congo craton has yielded δ 13 C and 87 Sr/ 86 Sr records through the later Cryogenian (ca. 750–600 Ma) and earlier part ofExpand
A global carbon isotope excursion (SPICE) during the Late Cambrian: relation to trilobite extinctions, organic-matter burial and sea level
Abstract The Steptoean positive carbon isotope excursion (SPICE) marks a global oceanographic event that confirms intercontinental correlations between different biogeographic realms based onExpand
Chronology of early Cambrian biomineralization
Abstract Data on the first appearances of major animal groups with mineralized skeletons on the Siberian Platform and worldwide are revised and summarized herein with references to an improved carbonExpand
Molluscan Phylogeny: The Paleontological Viewpoint
The fossil record indicates that the Monoplacophora gave rise to the Gastropoda, Cephalopoda, Rostroconchia, and possibly Polyplacophoras, and that the Pelecypoda and Scaphopoda are derived from the Rostroconschia. Expand
The Late Cambrian Spice (δ13C) Event and the Sauk II-SAUK III Regression: New Evidence from Laurentian Basins in Utah, Iowa, and Newfoundland
Carbon isotope data from Upper Cambrian sections in three Laurentian basins in northern Utah, central Iowa, and western Newfoundland record a large positive d 13 C excursion (SPICE event) of up to 1Expand
Precambrian oxygen levels estimated from the biochemistry and physiology of early eukaryotes
These estimates of the minimal oxygen requirements of known Precambrian eukaryotes do little at this stage to constrain models for the growth of atmospheric oxygen during the Proterozoic. Expand
Carbon isotope stratigraphy of the Precambrian–Cambrian Sukharikha River section, northwestern Siberian platform
A high-resolution carbon isotope profile through the uppermost Neoproterozoic–Lower Cambrian part of the Sukharikha section at the northwestern margin of the Siberian platform shows prominent secularExpand
Successive Refinements in Long-Term Integrations of Planetary Orbits
We report on accurate, long-term numerical simulations of the orbits of the major planets in our solar system. The equations of motion are directly integrated by a Stormer multistep scheme, which isExpand
Australian middle cambrian molluscs and their bearing on early molluscan evolution
Twenty-eight species of fifteen genera of Middle Cambrian molluscs are described from tiny phosphatic moulds or silica replicas of the shells. The molluscs were etched from limestones at two sites:Expand