Evrim Yazgin
Cosmos science journalist
One of the earliest examples of a winged seed has been found in a mine in China’s Anhui province. The fossil dates to 365 million years ago – a period known as the Femennian.
An examination of fossil seeds enables palaeontologists to understand how plants evolved and reproduced.
Before seeds, plants reproduced through spores. Ferns and moss, as well as some fungi, still disperse in this way today.
The first seeds were covered by a cupule – a cup-shaped structure – and did not evolve wings.
Only 2 plants are known to have developed wings during the Femnnian – both also discovered in China. These are Warsteinia (described in 1997) and Guazia (described in 2022). While Warsteinia has a cupule, Guazia does not.
Now many plants have winged seeds. These seeds take advantage of wind to travel great distances and extend the plant’s range. Some seeds have developed “helicopter”- or “parachute”-like structures to float and drop.
Prior research has shown that the first seeded plants evolved during the Femennian (371–359 million years ago) which came right at the end of the Devonian period, sometimes called the “Age of Fishes”.
The newly described species is dubbed Alasemenia tria. It was found by scientists looking for clues as to how wind dispersal evolved in plants. The fossil seeds were found in the Jianchuan mine in the Wutong Formation where fossilised seeds have been found before.
Alasemenia’s seeds are the second oldest ever found with wings. They are 2.5–3.3cm long and do not have a cupule. Closer inspection revealed a tough outer layer and 3 wing-like structures. Both Warsteinia and Guazia have 4 wing-like structures.
“Mathematical analysis shows that three-winged seeds are more adapted to wind dispersal than seeds with one, two or four wings under the same condition,” the authors write.
The finding is reported in a paper published in the journal eLife.
