An ancient beetle that nibbled a flower and got trapped in amber for nearly 100 million years has become the earliest direct evidence of insects pollinating flowering plants, researchers report today.
Scientists have long thought that insect pollination was key to the rapid spread of flowers during the Cretaceous period, about 145 million to 66 million years ago. But they’ve lacked solid evidence.
The new discovery is of a species of beetle known as Angimordella burmitina, which is related to a modern group of flower-visiting beetles. Dug up in northern Myanmar and obtained by scientists in 2012, the cloudy, seemingly mediocre amber fragment (pictured) that held the insect sat on a shelf for years. That is, until a paleontologist polished it and noticed the beetle was special. The insect had a curved body and head for reaching inside flowers to feed, and its mouthparts include leglike appendages for collecting and transporting pollen similar to those of modern beetle pollinators. The kicker: golden pollen covering its thorax, abdomen, and legs.
Researchers dated the beetle to 99 million years ago. But the real challenge was analyzing the poorly preserved 4-millimeter- long insect and 62 grains of pollen stuck between its body hairs. The scientists couldn’t determine the exact plant that produced the pollen, but it appears to be related to the eudicot group of flowering plants, which includes many of today’s trees and woody plants.
The find pushes back the history of insect pollination relationships by about 50 million years, the team reports today in the Proceedings of the National Academy of Sciences. The study authors say insect pollination likely happened even before this, and more primitive ancient pollinators are waiting to be found.