“…During the GOBE, many of the groups that dominated marine ecosystems until the Permian-Triassic mass extinction diversified and rose to ecological dominance. The diversification was accompanied by a variety of major ecological changes including i) increased tiering of benthic ecosystems (Bottjer & Ausich, 1986), ii) re-establishment of metazoandominated reefs (Kröger et al, 2017a), iii) expansion of nektonic and pelagic ecosystems (Servais et al, 2008;Kröger et al, 2009;Servais et al, 2015), and iv) establishment of a latitudinal diversity gradient (Kröger, 2018). Although the timing of diversification varied across clades and from region to region, much of the diversity increase occurred during the Early and Middle Ordovician, especially between the Dapingian (470 Ma) and Darriwilian (467 Ma) stages (Miller & Foote, 1996;Miller, 1997;Droser & Finnegan, 2003;Rasmussen et al, 2016;Trubovitz & Stigall, 2016;Kröger, 2018).…”