Fig. 4: Analysis of chain tilt angles.

a Map of the chain tilt angle φ with respect to Fig. 3a, b. b Histogram of φ for all the lamellae shown in (a) and Supplementary Figs. 12 and 13. The histogram was normalized by the total area of the lamellae analysed for the determination of φ. The broad peak exhibits a peak top at ~15°. c–e Isolated lamellae from Regions 2, 5, and 7, respectively, with large φ values (close to 34°). f–h Stacked lamellae from Regions 1, 2, and 5, respectively, with small φ values (<34°). i Histograms of φ for isolated and stacked lamellae. The histogram for isolated lamellae was normalized by the total area of the isolated lamellae, and that for stacked lamellae was normalized by the total area of the stacked lamellae. Because stacked lamellae were dominant in the present specimen, the histogram for all lamellae shown in (b) exhibits a feature similar to that for the stacked lamellae.