This figure shows how different ecological-evolutionary groups of insect pollinators either survived, originated or went extinct in the transition from gymnosperm to flowering plant dominance. Many gymnosperm pollinators, such as the beetle Darwinylus marcosi, made a successful transition to angiosperms. Other pollinators, such as bees, originated during or after flowering plants evolved and have no gymnosperm associations in their history. Some insect pollinators, such as some long-proboscid flies that depended upon gymnosperms and couldn’t make the transition, went extinct. Another group, including certain thrips, retained their associations with gymnosperms and survived, but saw a major drop in their diversity.
Courtesy of Conrad Labandeira and Finnegan Marsh (Department of Paleobiology, National Museum of Natural History, Washington, DC, USA), and José Antonio Peñas (digital scientific illustrator from Madrid, Spain)