Figure 4.

Engagement edges in the seed-producing structures of extinct and extant groups. Reproductive structures from each group are plotted by their average age and coloured by the number of engagement edges. Extant groups are shown in bold and a provisional phylogeny is provided to the left. Double branches leading to taxa indicate either paraphyletic or polyphyletic groups. ANA grade angiosperms refers to the Amborella, Nymphaeales and Austrobaileyales lineages. Phylogenetic relationships among extinct groups are largely unresolved; overall topology primarily reflects [37,49–51].