2004/07/01 by Emmanuelle Javaux, Andrew H. Knoll, Malcolm R. Walter · 2 citations
Earth and Planetary Sciences · Environmental Science · #Paleontology and Stratigraphy of Fossils #Geology and Paleoclimatology Research #Methane Hydrates and Related Phenomena #Proterozoic #Archean #Extant taxon #Geology #Geologic record #Ultrastructure #Paleontology #Arctic #Evolutionary biology #Biology #Tectonics #Botany #Oceanography
paper · doi:10.1111/j.1472-4677.2004.00027.x
openalex publication_date 2004/07/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23
ABSTRACT Biomarker molecular fossils in 2770 Ma shales suggest that the Eucarya diverged from other principal domains early in Earth history. Nonetheless, at present, the oldest fossils that can be assigned to an extant eukaryotic clade are filamentous red algae preserved in ca. 1200 Ma cherts from Arctic Canada. Between these records lies a rich assortment of potentially protistan microfossils. Combined light microscopy, scanning electron microscopy, and transmission electron microscopy on 1500‐1400 Ma fossils from the Roper Group, Australia, and broadly coeval rocks from China show that these intermediate assemblages do indeed include a moderate diversity of eukaryotic remains. In particular, preserved cell wall ultrastructure, observed using transmission electron microscopy (TEM), can help to bridge the current stratigraphic gap between the unambiguous eukaryotic morphologies of later Proterozoic assemblages and molecular biomarkers in much older rocks.