Supplementary Fig. 3. SDD calculated at the locality/species level for the NWE province and the MED province for each chronozone of the early Pliensbachian, after grouping the species according to the volume of their shell

Similarity distance decay calculated at the locality/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 volume of their shell (V = ln(volume) in mm3), in order to determine if there is a relationship between shell size and long-distance dispersal. For each province, the lower graphs represent the small species and the upper graphs the large ones. The black lines are the Ordinary Least-Square linear regressions and the SDD rates are the values of their slopes.

本数据集针对早普林斯巴阶（early Pliensbachian）的各个年代带，先依据物种壳体体积（V=ln(体积)，单位：mm³）对物种进行分组，以探究壳体大小与长距离扩散能力之间的关联；随后在局域/物种水平上，计算了西北欧（NWE）生物地理区（对应A-F组图）与地中海（MED）生物地理区（对应G-L组图）的相似性距离衰减值。
针对每个生物地理区，下方图表代表小型物种，上方图表则代表大型物种。
图中黑色线条为普通最小二乘（Ordinary Least-Square）线性回归拟合曲线，其斜率值即为相似性距离衰减（Similarity Distance Decay, SDD）速率。