**FIGURE 1.** APC distribution for all journals that have a ‘gold’ OA option. An APC of zero denotes a ‘diamond’ OA journal.

**FIGURE 2.** Publisher-imposed embargo periods on sharing of postprints (months).

**FIGURE 3.** Histogram of SNIP scores for palaeontology journals.

**FIGURE 4.** Histogram of impact factor scores for palaeontology journals.

**FIGURE 5.** Relationship between SNIP and IF for palaeontology journals, with a fitted linear regression (the grey shaded area represents the 95% confidence intervals for the model). R-squared = 0.899.

**FIGURE 6.** Relationship between SNIP and APC. R-squared = 0.135.

**FIGURE 7.** Relationship between IF and APC. R-squared = 0.227.