Flowers have been brightening Earth much longer than scientists previously believed—by at least two million years.
In a new study, researchers from Leibniz University Hannover and the University of Bonn discovered fossilized pollen grains that date the first appearance of flowering plants, known as angiosperms, to around 123 million years ago.
These pollen grains are incredibly small—no larger than 0.02 millimeters—but they hold powerful clues about the distant past.
The research team found them in ancient marine sediments along the coast of what is now Portugal.
These deposits belong to the Lusitanian Basin and were once part of a shallow sea where rivers carried pollen and plant material more than 100 million years ago.
Until now, it was widely believed that a major group of flowering plants called eudicots first appeared about 121 million years ago.
Eudicots include many modern plants, such as roses, sunflowers, and oaks. But this new discovery pushes that timeline back by two million years, making it the most precise evidence yet for the early presence of these plants.
To identify the ancient pollen, the scientists used a powerful method called laser scanning microscopy.
This allowed them to find four pollen grains with a very specific shape: each had three tiny furrows, a feature known as “tricolpate.” Today, about 72% of all flowering plants have tricolpate pollen, making it a strong marker for eudicots.
To confirm the age of the sediment in which the pollen was found, the researchers also studied fossilized seashells from the same rock layer. These shells, made of calcium carbonate, carry a chemical record of the seawater they formed in. By analyzing their strontium isotope levels and comparing them with global reference data, the scientists were able to date the sediment with high accuracy.
Flowering plants are now the most diverse group of land plants, but their origins have remained mysterious.
Charles Darwin even referred to the sudden appearance of flowering plants in the fossil record as an “abominable mystery.” While scientists still don’t know exactly how and where flowers first evolved, this discovery offers a new piece of the puzzle.
Interestingly, the location of the Lusitanian Basin suggests that early flowering plants may have been more widespread in mid-latitude regions than once thought.
The study also shows how combining different scientific techniques—such as analyzing pollen shape and using isotope dating—can help us better understand the evolution and spread of plant life on Earth.
The research is published in the Proceedings of the National Academy of Sciences.
