Fossil steroids record the appearance of Demospongiae during the Cryogenian period

@article{Love2009FossilSR,
  title={Fossil steroids record the appearance of Demospongiae during the Cryogenian period},
  author={G. Love and E. Grosjean and C. Stalvies and D. Fike and J. Grotzinger and A. Bradley and A. Kelly and M. Bhatia and W. Meredith and C. Snape and S. Bowring and D. Condon and R. Summons},
  journal={Nature},
  year={2009},
  volume={457},
  pages={718-721}
}
The Neoproterozoic era (1,000–542 Myr ago) was an era of climatic extremes and biological evolutionary developments culminating in the emergence of animals (Metazoa) and new ecosystems. Here we show that abundant sedimentary 24-isopropylcholestanes, the hydrocarbon remains of C30 sterols produced by marine demosponges, record the presence of Metazoa in the geological record before the end of the Marinoan glaciation (∼635 Myr ago). These sterane biomarkers are abundant in all formations of the… Expand
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The earliest Cambrian record of animals and ocean geochemical change
The Cambrian diversification of animals was long thought to have begun with an explosive phase at the start of the Tommotian Age. Recent stratigraphic discoveries, however, suggest that many taxaExpand
Hydrocarbon biomarkers for biotic and environmental evolution through the Neoproterozoic-Cambrian transition
The sequence of events over the Neoproterozoic Cambrian transition that led to the radiation of multicellular organisms has been an issue of debate for over a century. It is a critical interval inExpand
Possible poriferan body fossils in early Neoproterozoic microbial reefs
TLDR
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Reconstructing the strontium isotopic composition of Neoproterozoic seawater
The Tonian Period (1000 - c.720 Ma) followed a long interval of relative stasis, in terms of climate, carbon isotopes and biological evolution, and led into the Cryogenian Period of environmentalExpand
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