Angiosperm flowers reached their highest morphological diversity early in their evolutionary history

Abstract

Summary Flowers are the complex and highly diverse reproductive structures of angiosperms. Because of their role in sexual reproduction, the evolution of flowers is tightly linked to angiosperm speciation and diversification. Accordingly, the quantification of floral morphological diversity (disparity) among angiosperm subgroups and through time may give important insights into the evolutionary history of angiosperms as a whole. Based on a comprehensive dataset focusing on 30 characters describing floral structure across angiosperms, we used 1201 extant and 121 fossil flowers to measure floral disparity and explore patterns of floral evolution through time and across lineages. We found that angiosperms reached their highest floral disparity in the Early Cretaceous. However, decreasing disparity toward the present likely has not precluded the innovation of other complex traits at other morphological levels, which likely played a key role in the outstanding angiosperm species richness. Angiosperms occupy specific regions of the theoretical morphospace, indicating that only a portion of the possible floral trait combinations is observed in nature. The ANA grade, the magnoliids, and the early‐eudicot grade occupy large areas of the morphospace (higher disparity), whereas nested groups occupy narrower regions (lower disparity).

The evolutionary history of Coleoptera (Insecta) in the late Palaeozoic and the Mesozoic

“…Nonetheless, the earliest representatives of many herbivorous groups of beetles were already present before the Cretaceous, notably including Jurassic weevils (Gomez-Zurita et al, 2007;Gratshev & Zherikhin, 2003;Grimaldi & Engel, 2005;Hunt et al, 2007;Rainford & Mayhew, 2015;Shin et al, 2018;Zhang et al, 2018). It was also pointed out by L opez- Martínez et al (2023) that insects were active as pollinators before the origin of flowering plants (see also Peña-Kairath et al, 2023), and that insect pollination is ancestral for angiosperms as a whole (Stephens et al, 2023). In contrast, while different beetle groups appear to have codiversified with flowering plants, many diversified somewhat later, when flowering plants rose to ecological dominance (e.g., .…”

“…The Early Cretaceous crown diversification of angiospermous plants and their subsequent rise to ecological dominance (Barba-Montoya et al, 2018;Benton et al, 2022;Condamine et al, 2020;L opez-Martínez et al, 2023;Magall on et al, 2015) have been proposed as triggers for the proliferation of herbivorous beetles, based largely on similar age estimates for beetles and angiosperms in early molecular phylogenetic studies (Farrell, 1998;Farrell & Sequeira, 2004;Wilf, 2008). Nonetheless, the earliest representatives of many herbivorous groups of beetles were already present before the Cretaceous, notably including Jurassic weevils (Gomez-Zurita et al, 2007;Gratshev & Zherikhin, 2003;Grimaldi & Engel, 2005;Hunt et al, 2007;Rainford & Mayhew, 2015;Shin et al, 2018;Zhang et al, 2018).…”