High Evolutionary Turnover of Fusulinids During the Late Paleozoic Ice Age

Previous analyses suggested that the late Paleozoic ice age (LPIA) was characterized by depressed origination and extinction rates of marine invertebrates. Using a newly established global high temporal resolution dataset of fusulinids, a late Paleozoic group of larger benthic foraminifera, we tested the hypothesis of climatically depressed biodiversity dynamics in the LPIA and the influence of temporal and taxonomic resolutions. We found that turnover rates of fusulinids were higher during the LPIA than in the subsequent greenhouse interval of the Middle and Late Permian at all different temporal and taxonomic resolutions. We suggest that this pattern is related to clade-age dynamics, as the fusulinids emerged just before the LPIA with initially limited geographic ranges and biogeographic connectedness, which facilitated both extinction and origination. In addition, statistically defined evolutionary faunas provide evidence for gradual faunal replacements and a growing influence of origination on fusulinid diversification. Origination-driven diversification Origination-driven diversification happening in the late Paleozoic indicated that the end-Permian extinction may not be the main trigger for this shift in biodiversity dynamics.