Fig. 9

Plots of the mean ratio of spiral convexity (a) to umbilical convexity (b) per sample through time (in Ma) at Hole 925B for G. menardii (a), G. limbata (b), and G. multicamerata (c). Same explanation for symbols as in Fig. 5. For explanation of spiral convexity A and umbilical convexity B measurements refer to Fig. 4. Note the change in scale in d in order to highlight intermediate positions of mean convexity ratios of G. limbata (filled circles) at intervals when G. multicamerata showed strongest divergence. Data and statistics can be read from Tables 4a–c and 5a–c in the electronic supplementary materials