Figure S1: Changes in coiling and initial chamber size through time

(A) Diversity from the early Emsian to the late Eifelian with proportion of forms with openly coiled adult whorls and umbilical window (open + enclosed). The embryonic and post-embryonic whorls of representative taxa are shown of each category are shown (respectively Erbenoceras, Mimagoniatites and Agoniatites). (B-C) Boxplots showing the distribution and fluctuations of initial chamber size (initial chamber diameter PD in mm) within the Devonian (B) and in the Phanerozoic (C) from the Devonian until the Cretaceous (whiskers = minima and maxima excluding outliers, boxes = middle two quartiles, horizontal stripe = median value, dots = outliers). Abbreviations: E. Dev = Early Devonian, M. Dev. = Middle Devonian, L. Dev. = Late Devonian, Dev. = Devonian, Carb. = Carboniferous, Perm. = Permian, Tria = Triassic, Jura. = Jurassic, Cret. = Cretaceous. Histograms were produced in the freely available statistical environment R (http://www.r-project.org/).