Fusulinid Evolutionary Faunas of the late Paleozoic

Fusulinids, the earliest recorded group of larger benthic foraminifera, first appeared in the Early Carboniferous and flourished from the Late Carboniferous to the end of the Middle Permian. Their most notable diversification occurred during the Late Carboniferous to the earliest Permian, coinciding with the peak of the Late Paleozoic Ice Age (LPIA). Understanding in more detail the link between fusulinid diversification and climate changes could provide a unique perspective on evolutionary responses to climatic variability. Here, based on newly established patterns of high-temporal-resolution species richness and factor analysis, we recognize four evolutionary faunas akin Sepkoski’s evolutionary faunas. The four evolutionary faunas are pre-LPIA, early-LPIA, late-LPIA, and post-LPIA. These evolutionary faunas are characterized by long decline patterns (pre-LPIA and early-LPIA faunas), and extinction patterns with sudden eliminations of the whole fauna (late-LPIA and post-LPIA faunas). Further analyses revealed that the magnitude of climatic changes played a key role in shaping different diversity trajectories of fusulinid evolutionary faunas and the succession of faunas. Our findings offer insights into how different levels of climatic changes would influence global biodiversity over geological timescales.