Fig. 9From: Is the relative thickness of ammonoid septa influenced by ocean acidification, phylogenetic relationships and palaeogeographic position?Correlation of abiotic factors (vertical axes) with the septal slope factor (horizontal axis). A pH after Ridgwell (2005); B like A, but with average septal slope factors. C atmospheric CO2 (Witkowski et al., 2018). D like C, but with average septal slope factors. E Palaeolatitudal distribution using the maps of Kocsis and Scotese (2021). F Like E, but northern and southern latitudes fused. G Like F, but with average septal slope factor per latitude. H Like G, but without the outlier DivisosphinctesBack to article page