Fig. 3 in Early Jurassic anoxia triggered the evolution of the oldest holoplanktonic gastropod Coelodiscus minutus by means of heterochrony

Fig. 3. Correlation between the shell thickness and shell diameter; by linear bivariate modelling using Ordinary Least Squares Regression in PAST3 (Hammer et al. 2001). A. The data show that the shell of Coelodiscus minutus is generally very thin and shows a linear increase with shell diameter; this linear increase is generally typical of shelled molluscs and is also present in modern holoplanktonic gastropods. B. The log-transformed data of the original measurements confirm the linear increase with shell diameter. Abbreviations: N, number of bootstrap replicates; n, number of measured specimens; R2, coefficient of correlation; p, permutation test on correlation (R2), using 9999 replicates.