Bee Fossil and Orchid Origins
Biologists have identified the ancient fossilized remains of a pollen-bearing bee as the first hint of orchids in the fossil record. The finding suggests that orchids are old enough to have coexisted with dinosaurs, scientists say.
"Since the time of Darwin, evolutionary biologists have been fascinated with orchids' spectacular adaptations for insect pollination," explains the study's lead author Santiago R. Ramirez, a researcher in Harvard University's Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology. "But while orchids are the largest and most diverse plant family on Earth, they have been absent from the fossil record."
Ramirez says the fossil record lacks evidence of orchids because they bloom infrequently and are concentrated in tropical areas where heat and humidity prevent fossilization. The orchids' pollen is dispersed only by animals, not wind, and disintegrates upon contact with the acid used to extract pollen from rocks. The new findings indicate orchids arose some 76 to 84 million years ago, which is older than many scientists had estimated. The extinct bee studied by Ramirez's research team, preserved in amber with a mass of orchid pollen on its back, represents some of the only direct evidence of pollination in the fossil record. …