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

Abstract

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.

High-precision timeline for Earth’s most severe extinction

“…To better understand the relationship between environmental perturbation and biotic response, accurate and precise age models that integrate geochronology, paleontology, and geochemistry must be developed (8,11,16,17). Recognition of astronomically forced sedimentary cycles (Milankovitch cycles) in late Permian and Triassic sedimentary rocks tuned with available geochronology have been used to refine existing age models of the biotic crisis (18)(19)(20).…”

The effect of geographic range on extinction risk during background and mass extinction

“…1-3) suggests that per-plate extinction risk varied considerably among genera. Each of these events also is associated with geological and geochemical evidence for rapid, global environmental disruption coincident with geologically rapid extinction (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27). Previous studies have identified ecological and physiological extinction selectivity patterns that may account for differences in per-plate extinction risk among genera during these intervals.…”

Adaptation and acclimatization to ocean acidification in marine ectotherms: anin situtransplant experiment with polychaetes at a shallow CO2vent system

“…We suggest that in the face of elevated pCO 2 conditions, such as those experienced, for example, during the PermoTriassic boundary [112][113][114][115], the evolution (or development) of moderate metabolic depression may have enabled some marine organisms to persist locally and globally. This may have come, however, at the cost of some life-history traits, such as reduced body size: see [116] for a review on the Lilliput Effect.…”