Fig. S5.

Proof of methods in quantifying nonsinusoidal cycle properties. (A) Original skewness and asymmetry calculations on Plio-Pleistocene benthic and planktic δ¹⁸O records. Reprinted from ref. 27. (B) Reproducing the results of ref. 27 on the Plio-Pleistocene LR04 benthic δ¹⁸O stack (54). Comparable results have been obtained using a different method (32). Triangles show asymmetry, and circles show skewness. Turquoise indicates the standard method, and purple-pink represents the bispectral method. Time (Ma) equates to Age (My ago).