CHICAGO — Fossilized orchid pollen on the back of a bee preserved in amber has offered the first evidence that these delicate flowers existed around the time of the dinosaurs, U.S. researchers say.
Biologists at Harvard University said the ancient pollen, found in a clump on a now-extinct worker bee, means orchids are much older than previously thought.
While orchids are the largest and most diverse plant family on Earth, they have been largely absent from the fossil record, said Harvard researcher Santiago Ramirez, whose study appears in the journal Nature.
Orchids package their pollen in structures called pollinia, which consist of masses of pollen grains. It was that structure that caught Mr. Ramirez's eye.
An ancient bee carrying the pollen from the first orchid fossil known to science is seen in this handout photo from 2007. (Santiago Ramirez/Reuters)
"It is very distinct. Because of its shape and form, we were able to identify it right away," Mr. Ramirez said in a telephone interview. "Orchids were missing in the fossil record until this was found."
The absence of orchids from the fossil record has fuelled debate about their age, with estimates ranging from 26 million to 112 million years ago.
The amber-encased bee was first discovered in the Dominican Republic by a private collector in 2000. It made its way to Harvard's Museum of Comparative Zoology in 2005.
The worker bee specimen is 15 to 20 million years old, but Mr. Ramirez and colleagues used its payload of pollen to analyze the orchid species. They used a molecular-clock method of analysis to estimate the age of the orchid family, which they date to about 80 million years ago.
The dinosaurs' extinction occurred about 65 million years ago.
Mr. Ramirez said the find not only helps resolve a debate over the age of the orchid but it provides the first direct evidence of ancient pollination.
"This is one of the first fossil observations in which you can find both the pollinator and the plant together," he said.
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