Impact Of Permian Mass Extinctions On Continental Invertebrate Infauna

The Capitanian (late middle Permian) and end-Permian mass extinctions were particularly severe from a palaeoecological perspective. Previous studies of their expressions on land underscored their impacts on plants and vertebrates, but the effects on the continental invertebrate infauna remain poorly understood. A multiproxy analysis from the Iberian Basin (Central Spain) reveals a dramatic decrease in bioturbation intensity on land by the end of the Capitanian. This pattern cannot be explained by facies effects because our analysis is based on similar types of deposits through the succession and over an extensive area. The bioturbation crisis coincided with an increase in weathering intensity and acidic conditions, and a collapse in plant communities spanning the late Permian-Early Triassic in the Iberian Basin. Reduced bioturbation may have contributed to decrease in mechanical reworking of the sediment and soil, affected geochemical recycling, increased sediment acidification and impacted on ecosystem structure. Identification of this infaunal crisis on land underscores the ecological severity of mass extinctions and emphasises the significance of feedback loops in riparian ecosystems.