Supplementary Fig. 6. SDD calculated at the cluster/species level for the NWE province and the MED province for each chronozone of the early Pliensbachian, after grouping the species according to the relative whorl height of their shell

Similarity distance decay calculated at the cluster/species level for the NWE province (A-F) and the MED province (G-L) for each chronozone of the early Pliensbachian, after grouping the species according to the relative whorl height of their shell (H / D, H = last-whorl height, D = shell diameter), in order to determine whether a relationship between shell shape and long-distance dispersal exists. For each province, the lower graphs represent the most evolute species and the upper graphs the most involute ones. Only clusters with at least 3 species are considered in these analyses. The black lines are the Ordinary Least-Square linear regressions and the SDD rates are the values of their slopes.