In a new study from Oregon State University, researchers are describing a previously unknown flower species that dates back 100 million years. The analysis of a well-preserved specimen, which is encased in amber, is also shedding new light on the breakup of the supercontinent Gondwana.
Study lead author Professor George Poinar is an international expert in using plant and animal life forms preserved in amber to learn more about the biology and ecology of the distant past.
“This isn’t quite a Christmas flower but it is a beauty, especially considering it was part of a forest that existed 100 million years ago,” said Professor Poinar.
“The male flower is tiny, about 2 millimeters across, but it has some 50 stamens arranged like a spiral, with anthers pointing toward the sky.”
A stamen consists of an anther, which produces pollen, and a stalk that connects the anther to the flower.
“Despite being so small, the detail still remaining is amazing,” said Professor Poinar. “Our specimen was probably part of a cluster on the plant that contained many similar flowers, some possibly female.”
The flower has an egg-shaped, hollow floral cup. This is the part of the flower from which the stamens emerge. The cup contains an outer layer consisting of six petal-like components known as tepals, and two-chamber anthers with elaborate pollen sacs.
In collaboration with experts at the U.S. Department of Agriculture, Professor Poinar and his team named the new flower Valviloculus pleristaminis. Valva is the Latin term for the leaf on a folding door, loculus means compartment, plerus refers to many, and staminis represents the dozens of male sex organs found on the flower.
The specimen was sealed in amber on the ancient supercontinent of Gondwana during the mid-Cretaceous period. Then, the specimen was carried on a continental plate across 4,000 miles of ocean from Australia to Southeast Asia, said Professor Poinar.
It has been a mystery to geologists when this chunk of land – known as the West Burma Block – broke away from Gondwana. While some believe it was 200 million years ago; others believe it was around 500 million years ago.
Since angiosperms only evolved and diversified about 100 million years ago, the West Burma Block could not have broken off from Gondwana before then, explained Professor Poinar. This is much later than the dates that were previously predicted.
The study is published in the Journal of the Botanical Research Institute of Texas.