Chinese And U.S. Scientists Identify The World's Oldest Flowering Plant
GAINESVILLE, Fla. --- On the floor of a steamy Asian forest, a woody plant destined for immortality was thriving among the dragonflies and dinosaurs when a nearby volcano erupted and left it buried in ash.
Some 140 million years later, Chinese and American researchers have retrieved the fossilized remains of that scrap of vegetation and given it a label sure to get the attention of botanists and plant lovers everywhere.
"This is the world's oldest flowering plant," said David Dilcher, a graduate research professor at the University of Florida.
In a paper to be published Friday (11/27) as the cover story of the journal Science, Dilcher and Sun Ge, vice director of the Institute of Geology and Paleontology at the Academia Sinica in Nanjing, China, lay out the evidence of the ancient plant. The find, Sun and Dilcher say, predates the previous oldest-known flower by more than 25 million years.
"We're finding, back into the Jurassic, the roots of flowering plants, which demonstrates that a line of plants related to the magnolia ... is a very early part of plant ancestry," said Dilcher, who works at the Florida Museum of Natural History at UF. "It gives hope to other investigators to search in this age sediment for evidence of early flowers"
William L. Crepet, chairman of the L.H. Bailey Hortorium at Cornell University, has written a piece for Science that will accompany Sun's and Dilcher's.
"As more characters become known from additional fossil discoveries," Crepet said, "this fossil may help us to understand the relationships among existing species -- a major problem about which there is considerable controversy. These are major evolutionary questions."
The plant is nothing on the order of present-day magnolias or chrysanthemums, though, because it had no petals. It is a flower by scientific definition, it had carpels, or leaf-like pods that opened to release seeds. Non-flowering plants have no such structures.
"It's what we would call a pre-floral flower," he said.
Imbedded in a chunk of limestone, the long-extinct plant's remains -- two stems, eachabout 3 inches long --were found last year in northeast China, near the town of Beipiao about 250 miles northeast of Beijing. They came from a spot known as the Yixian formation, made famous during the last decade or so for its large number of pristine fossils of dinosaurs, insects, fish and other ancient life.
The plant fossil made its way to Sun by way of colleagues and local residents. Sun knew it was a significant find and sought out Dilcher's botanical expertise. In March, Sun brought the specimen to Gainesville and the two scientists spent two weeks poring over it.
A key in identifying it as an early flowering plant was the presence of seeds that were preserved in the fossil. The seeds provided solid proof that this was, indeed, a flowering plant. "If we hadn't gotten a seed out of this thing, we couldn't say what we're saying," Dilcher said.
Because only part of the plant was fossilized much of its appearance remains a mystery. "We don't know if it was a tree or a shrub," Dilcher said, "although common wisdom has it that the early flowering plants may have been probably woody."
Previously, the oldest-known flower was a 115-million-year-old specimen found in Australia about nine years ago. Although Canadian researchers date the Yixian formation at about 120 million years old, Dilcher said Chinese researchers used radiometric dating to place the age of Sun's and his plant at between 142 million and 148 million years old.
Not that the difference is worth quibbling over. "Either way," Dilcher said, "this is still the oldest flowering plant."
Furthermore, he said, that distinction may be fleeting.
"I don't think this was the one and only first flower," he said. In fact, other research suggests flowering plants may have existed a few million years before Sun's and Dilcher's.
But all that's been found of the others, he said, is inconclusive evidence such as pollen, leaves and the like. "People don't know what to make of that," Dilcher said. "This, people will believe."
University Of Florida. November 1998.
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