A review of Paleozoic phytoplankton biodiversity: Driver for major evolutionary events?

Phytoplankton form the base of most marine trophic chains and studying their past diversity at regional global scales can provide valuable insights into evolution ecosystems climate history. Using a new database more than 4000 species acritarchs prasinophytes, comprehensive investigation taxonomic trajectories this (micro)phytoplankton throughout Paleozoic is performed for first time. This dataset compiles data from published literature, including taxonomic, geographic stratigraphic information stage resolution. Our results highlight five major temporal trends in phytoplankton variation: (i) an initial plateau moderate richness during early middle Cambrian, followed by (ii) sharp increase late Cambrian to Middle Ordovician, which records highest organic-walled (OWP); then, (iii) protracted decrease Late Ordovician Devonian; (iv) slight peak Devonian, before (v) falling lowest recorded Carboniferous Permian. The role biotic events discussed: While may have been factor enabling “Cambrian Explosion”, we do not find strong relationship between changes event thus refute notion that it might driver radiations interval. However, coincides with Great Biodiversification Event (GOBE), indicating profound phytoplankton, food webs, enabled diversifications ecosystems. A Lower Devonian points against hypothesis triggering proposed “Devonian Nekton Revolution”. By comparing paleoenvironmental parameters, several factors are found be possibly related long-term trends: indicate paleogeography sea-level were probably main drivers patterns Paleozoic, while increases sediment influx provided facilitating conditions diversification. Atmospheric CO2 concentration as well temperature sea ice cover further important controlling diversity.