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Archean molecular fossils and the early rise of eukaryotes.
TLDR
The presence of steranes, particularly cholestane and its 28- to 30-carbon analogs, provides persuasive evidence for the existence of eukaryotes 500 million to 1 billion years before the extant fossil record indicates that the lineage arose. Expand
2-Methylhopanoids as biomarkers for cyanobacterial oxygenic photosynthesis
TLDR
It is shown that 2-methylbacteriohopanepolyols occur in a high proportion of cultured cyanob bacteria and cyanobacterial mats and are abundant in organic-rich sediments as old as 2,500 Myr, which may help constrain the age of the oldest cyanobacteria and the advent of oxygenic photosynthesis. Expand
Oxidation of the Ediacaran Ocean
TLDR
High-resolution carbon isotope and sulphur isotope records from the Huqf Supergroup, Sultanate of Oman, that cover most of the Ediacaran period indicate that the ocean became increasingly oxygenated after the end of the Marinoan glaciation and allow us to identify three distinct stages of oxidation. Expand
Biomarker evidence for green and purple sulphur bacteria in a stratified Palaeoproterozoic sea
TLDR
Hydrocarbon biomarkers from a 1.64-Gyr-old basin in northern Australia reveal a marine basin with anoxic, sulphidic, sulphate-poor and permanently stratified deep waters, hostile to eukaryotic algae, and support mounting evidence for a long-lasting Proterozoic world in which oxygen levels remained well below modern levels. Expand
Rapid oxygenation of Earth’s atmosphere 2.33 billion years ago
TLDR
The new data suggest that the oxygenation occurred rapidly—within 1 to 10 million years—and was followed by a slower rise in the ocean sulfate inventory, whereas the relationships among GOE, “Snowball Earth” glaciation, and biogeochemical cycling will require further stratigraphic correlation supported with precise chronologies and paleolatitude reconstructions. Expand
A Serpentinite-Hosted Ecosystem: The Lost City Hydrothermal Field
The serpentinite-hosted Lost City hydrothermal field is a remarkable submarine ecosystem in which geological, chemical, and biological processes are intimately interlinked. Reactions between seawaterExpand
A reconstruction of Archean biological diversity based on molecular fossils from the 2.78 to 2.45 billion-year-old Mount Bruce Supergroup, Hamersley Basin, Western Australia
Abstract Bitumens extracted from 2.7 to 2.5 billion-year-old (Ga) shales of the Fortescue and Hamersley Groups in the Pilbara Craton, Western Australia, contain traces of molecular fossils. Based onExpand
Dynamics of the Neoproterozoic carbon cycle
TLDR
It is suggested that the most significant of the Neoproterozoic negative carbon-isotopic excursions resulted from increased remineralization of this reservoir, a process that was likely initiated by evolutionary innovations that increased export of organic matter to the deep sea. Expand
Intact polar membrane lipids in prokaryotes and sediments deciphered by high-performance liquid chromatography/electrospray ionization multistage mass spectrometry--new biomarkers for biogeochemistry
TLDR
Results are reported from analyses of IPLs in pure cultures of biogeochemically relevant prokaryotes and marine sediments by high-performance liquid chromatography/electrospray ionization ion-trap mass spectrometry (HPLC/ESI-IT-MSn) and analytical protocols are presented to decipher structural information from mass spectral data. Expand
Fossil steroids record the appearance of Demospongiae during the Cryogenian period
TLDR
It is suggested that shallow shelf waters in some late Cryogenian ocean basins contained dissolved oxygen in concentrations sufficient to support basal metazoan life at least 100 Myr before the rapid diversification of bilaterians during the Cambrian explosion. Expand
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