Late-Neoproterozoic Deep-Ocean Oxygenation and the Rise of Animal Life

  title={Late-Neoproterozoic Deep-Ocean Oxygenation and the Rise of Animal Life},
  author={Donald E. Canfield and Simon W. Poulton and Guy M. Narbonne},
  pages={92 - 95}
Because animals require oxygen, an increase in late-Neoproterozoic oxygen concentrations has been suggested as a stimulus for their evolution. The iron content of deep-sea sediments shows that the deep ocean was anoxic and ferruginous before and during the Gaskiers glaciation 580 million years ago and that it became oxic afterward. The first known members of the Ediacara biota arose shortly after the Gaskiers glaciation, suggesting a causal link between their evolution and this oxygenation… 
Ferruginous Conditions Dominated Later Neoproterozoic Deep-Water Chemistry
It is reported that through much of the later Neoproterozoic, anoxia remained widespread beneath the mixed layer of the oceans; deeper water masses were sometimes sulfidic but were mainly Fe2+-enriched, marking a return to ocean chemistry not seen for more than one billion years of Earth history.
On the coevolution of Ediacaran oceans and animals
Fe speciation and S-isotope of pyrite data from the terminal Proterozoic Sheepbed Formation in Canada and Doushantuo Formation in China reveal that ocean deep waters were anoxic after the global glaciations, but that marine sulfate concentrations and inferentially atmospheric oxygen levels were higher than before the glaciations.
The case for a Neoproterozoic Oxygenation Event: Geochemical evidence and biological consequences
The Neoproterozoic era marked a turning point in the development of the modern earth system. The irreversible environmental changes of that time were rooted in tectonic upheavals that drove chain
Low-oxygen waters limited habitable space for early animals
Anomalous cerium enrichments preserved in carbonate rocks across bathymetric basin transects from nine localities of the Nama Group, Namibia suggest that low-oxygen conditions occurred in a narrow zone between well- oxygengenated surface waters and fully anoxic deep waters, demonstrating that oxygen availability was a key requirement for the development of early animal-based ecosystems.
Rise to modern levels of ocean oxygenation coincided with the Cambrian radiation of animals
New molybdenum isotope data are presented that demonstrate that the areal extent of oxygenated bottom waters increased in step with the early Cambrian bioradiation of animals and eukaryotic phytoplankton, marking the first establishment of a key environmental factor in modern-like ecosystems.
Integrated Evolution of Cnidarians and Oceanic Geochemistry Before and During the Cambrian Explosion
Molecular phylogenetic analysis reveals that the splitting of the phylum Cnidaria into Anthozoa and Medusozoa probably took place in deep time as early as Cryogenian–Ediacaran (720–635 Ma), a long
Ocean Chemistry and Early Animals
Redox conditions in the late Neoproterozoic Doushantuo Formation of southern China are elucidated, which contain superbly preserved eggs, embryos, and probable resting cysts that are generally regarded as the oldest-known microscopic animals.
A Review of the Neoproterozoic Global Glaciations and a Biotic Cause of Them
  • J. Casado
  • Geography, Environmental Science
    Earth Systems and Environment
  • 2021
In the Neoproterozoic Era, the Earth experienced two broad intervals of global glaciation, commonly known as Snowball Earth. There was also a rapid diversification of life, with the evolution of most
Devonian rise in atmospheric oxygen correlated to the radiations of terrestrial plants and large predatory fish
The isotopic composition and concentration of molybdenum in sedimentary rocks are used to couple the redox history of the atmosphere and oceans to major events in animal evolution, suggesting two episodes of global ocean oxygenation and suggesting that early metazoans evolved in a relatively low oxygen environment.
A global transition to ferruginous conditions in the early Neoproterozoic oceans
Eukaryotic life expanded during the Proterozoic eon1, 2.5 to 0.542 billion years ago, against a background of fluctuating ocean chemistry2, 3, 4. After about 1.8 billion years ago, the global ocean


Oxidation of the Ediacaran Ocean
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.
Biomarker Evidence for Photosynthesis During Neoproterozoic Glaciation
Laterally extensive black shales deposited on the São Francisco craton in southeastern Brazil during low-latitude Neoproterozoic glaciation are interpreted as representing the preserved record of abundant marine primary productivity from glacial times, providing important constraints for parts of the “Snowball Earth” hypothesis.
The transition to a sulphidic ocean ∼ 1.84 billion years ago
The Proterozoic aeon (2.5 to 0.54 billion years (Gyr) ago) marks the time between the largely anoxic world of the Archean (> 2.5 Gyr ago) and the dominantly oxic world of the Phanerozoic (< 0.54 Gyr
U-Pb Ages from the Neoproterozoic Doushantuo Formation, China
U-Pb zircon dates from volcanic ash beds within the Doushantuo Formation (China) indicate that its deposition occurred between 635 and 551 million years ago, indicating synchronous deglaciation.
Calibration of Sulfate Levels in the Archean Ocean
Sulfur isotope fractionation experiments on marine and freshwater sulfate reducers, together with the isotope record, imply that oceanic Archean sulfate concentrations were less than one-hundredth of present marine sulfate levels and one-fifth of what was previously thought.
THE EDIACARA BIOTA: Neoproterozoic Origin of Animals and Their Ecosystems
Present evidence suggests that the Ediacara biota included a mixture of stem- and crown-group radial animals, stem-group bilaterian animals, “failed experiments” in animal evolution, and perhaps representatives of other eukaryotic kingdoms.
The early evolution of eukaryotes: a geological perspective.
Polecular phylogenies of eukaryotic organisms imply patterns of biological and environmental history that can be tested against the geological record, and Precambrian rocks show evidence of episodic increases in biological diversity and atmospheric oxygen concentrations.
Paleoenvironmental analysis of the late Neoproterozoic Mistaken Point and Trepassey formations, southeastern Newfoundland
The Mistaken Point and Trepassey formations (Conception and St. John's groups, respectively) comprise a terminal Neoproterozoic, deep-marine succession of fine-grained turbidites and volcanogenic
Explaining the Cambrian "Explosion" of Animals
The Cambrian “explosion” is a unique episode in Earth history, when essentially all the animal phyla first appear in the fossil record and is best understood as being the result of the interplay of the combinatorial bilaterian developmental system and the increase in the number of needs the first bilaterians had to meet as complex ecological interactions developed.