Late Palaeozoic brachiopod diversity: global vs regional trends

The study of biodiversity during the late Palaeozoic can provide useful insights into the evolution of the biosphere during dramatic climate and environmental changes such as the Late Palaeozoic Ice Age and the end-Permian hothouse. Here, we present a genus- by stage-level analysis of brachiopod diversity through the late Palaeozoic, using datasets obtained from three major palaeontological databases – Paleobiology Database, Geobiodiversity Database and Sepkowski’s Online Genus Database – from a global to a regional scale. Our analysis is grounded in original palaeogeographic reconstructions that constrain the co-evolution of organisms and the environment in the late Palaeozoic, showing that biodiversity evolved at different rates across both temporal and spatial scales. The onset of the LPIA does not appear to have directly influenced global brachiopod diversity, though a nadir in brachiopod diversity is recorded in the Serpukhovian-Kasimovian. The demise of LPIA affected regional records in Gondwanan and peri-Gondwanan areas, and it may also have had a global impact as recorded by an increase in time-standardized genus richness, while climate warming and plate reorganization from Pangaea-B to Pangaea-A, the opening of the Neo-Tethys, and the increase in low-latitude margin availability may have contributed to the Guadalupian diversity peak, which is evident in nearly all the analysed datasets. Comparisons among the three databases reveal discrepancies in diversity, origination, and extinction patterns—highlighting regional biases, data gaps, and dataset errors—and suggest that while occurrence-based data are more reliable for regional diversity estimates, stratigraphic range-based data better capture broad global trends, albeit with inherent limitations.