<p><strong>A unique flower in Miocene amber sheds new light on the evolution of flowers</strong></p>

Abstract

The evolution of flowers is among the foremost topics in evolutionary science. The question for botanists of how flowers evolved exists mainly due to lack of relevant fossil evidence, especially of well-preserved flowers. Dominican amber has yielded abundant fossils (including those of flowers) and thus opens a unique window on flower evolution. Here we report a unique flower preserved in mid-Miocene Dominican amber, Dinganthus pentamera gen. et sp. nov. The flower is actinomorphic, pentamerous, bisexual flower including two bracts, five tepals, 10 stamens, and gynoecium. The stamens are dorsifixed, filamentous, and latrorse. The gynoecium in the centre comprises three portions, namely, a basal gynophore, multiple ovaries in the middle, and an apical style. Supplementing to the developmental and genetic evidence, the unique morphology of Dinganthus suggests that a flower is a condensed shoot with lateral appendages, a long-held belief in botany.