Cindy V. Looy

Rapid and synchronous collapse of marine and terrestrial ecosystems during the end-Permian biotic crisis

A newly studied Permian-Triassic (P-Tr) boundary section in Jameson Land, East Greenland, contains an abundant and well-preserved marine fauna as well as terrestrial palynomorphs. For the first time it is possible to compare the biotic crises of the marine and terrestrial realms using the same samples from the same section. The sediments record a negative excursion in δ 13 C carb values of 8‰–9‰, and in δ 13 C org values of 10‰–11‰. The presence of the conodont Hindeodus parvus, combined with the δ 13 C carb record, enables correlation with the proposed global stratotype section at Meishan. This shows that the Greenland section is the most expanded P-Tr section known. Collapse of the marine and terrestrial ecosystems took between 10 and 60 k.y. It took a further few hundred thousand years for the final disappearance of Permian floral elements. Collapse of the terrestrial and marine ecosystems began at the same stratigraphic level and preceded the sharp negative excursion in the δ 13 C record.

Life in the end-Permian dead zone.

The fossil record of land plants is an obvious source of information on the dynamics of mass extinctions in the geological past. In conjunction with the end-Permian ecological crisis, ≈250 million years ago, palynological data from East Greenland reveal some unanticipated patterns. We document the significant time lag between terrestrial ecosystem collapse and selective extinction among characteristic Late Permian plants. Furthermore, ecological crisis resulted in an initial increase in plant diversity, instead of a decrease. Paradoxically, these floral patterns correspond to a “dead zone” in the end-Permian faunal record, characterized by a paucity of marine invertebrate megafossils. The time-delayed, end-Permian plant extinctions resemble modeled “extinction debt” responses of multispecies metapopulations to progressive habitat destruction.

Catastrophic soil erosion during the end-Permian biotic crisis

Organic geochemical analyses of sedimentary organic matter from a marine Permian-Triassic transition sequence in northeastern Italy reveal a significant influx of land-derived diagenetic products of polysaccharides. This unique event reflects massive soil erosion resulting from destruction of land vegetation due to volcanogenic disturbance of atmospheric chemistry. The excessive supply of soil materials to the oceans provides a direct link between terrestrial and marine ecological crises, suggesting that ecosystem collapse on land could have contributed to the end-Permian marine extinctions.

Multiple Organic Carbon Isotope Reversals across the Permo‐Triassic Boundary of Terrestrial Gondwana Sequences: Clues to Extinction Patterns and Delayed Ecosystem Recovery

Organic materials across the palynologically defined Permian‐Triassic (P‐T) boundary from five major terrestrial basins in the interior of the former Gondwana Supercontinent show large to very large (5‰–15‰) multiple negative spikes of δ13C, separated in places by sharp reversals of up to 20‰. Large oscillations of δ13Corg between −36‰ and −15‰ from mean values of ∼ \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape

Is the vertebrate-defined Permian-Triassic boundary in the Karoo Basin, South Africa, the terrestrial expression of the end-Permian marine event?

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Fungal virulence at the time of the end-Permian biosphere crisis?

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Cyclic diaryl ethers in a Late Permian sediment

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