Fungal abundance spike and the Permian-Triassic boundary in the Karoo Supergroup (South Africa)

摘要

The most severe mass extinction of marine species and terrestrial vertebrates and plants is associated with the Permian-Triassic boundary (～251 Ma). The extinction interval is also marked by the disappearance of most Late Permian gymnosperm palynomorphs at a layer containing solely the abundant remains of fungi. This 'fungal spike' apparently represents widespread devastation of arboreous vegetation. Stratigraphic and palynological study of the Carlton Heights section in the southern Karoo Basin of South Africa revealed a 1-m-thick fungal spike zone that occurs simultaneously with the last appearance of typically Late Permian gymnosperm pollen. The plant extinction and fungal spike zone are found above the last occurrence of Late Permian mammal-like reptiles of the Dicynodont Zone at other Karoo sections. Using the fungal event as a time line in marine and non-marine sections allows placement of the marine extinctions and the extinction of terrestrial plants and reptiles within a brief crisis interval of less than about 40 000 years at the end of the Permian.