Researchers report a beetle preserved in Burmese amber that suggests early evidence of insect pollination of flowering plants. Insects are thought to have pollinated flowering plants during the Cretaceous Period, when flowering plants rapidly diversified. However, direct evidence of insect pollination of Cretaceous flowering plants is lacking. Bo Wang, David Dilcher, and colleagues report the discovery of a tumbling flower beetle preserved in mid-Cretaceous Burmese amber that bears evidence suggesting insect pollination of flowering plants. Encased in the fragment of amber, approximately 99 million years old and recovered from a mine in northern Myanmar, the beetle, Angimordella burmitina, exhibited a suite of evidence suggesting its role as a pollinator: a curved, compressed, and wedge-shaped body with a declined head that likely facilitated feeding inside flowers, well-developed hind legs to move between flowers, fine hairs on the thorax and abdomen whose height and spacing are apt for holding and transporting pollen, and modified mouthparts seemingly tailored for collecting and likely transporting pollen. The beetle's thorax and abdomen were dusted with tricolpate pollen, a defining feature of the eudicot group of flowering plants. The pollen grains' reticulate surfaces and signs of pollen clumping together suggest beetle-aided pollination. Previous evidence of insect pollination of flowering plants dates to the Middle Eocene, around 48-45 million years ago. Thus, the finding deepens the history of insect pollination of flowering plants by around 50 million years and suggests the existence of such mutualism at least as far back as 99 million years ago, according to the authors.
Article #19-16186: " Pollination of Cretaceous flowers," by Tong Bao, Bo Wang, Jianguo Li, and David Dilcher