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Charles Darwin referred to the origin of flowers as ‘an abominable mystery.’ However, their origins can now be associated with fossilized plants from 126 million years ago.

Darwin’s puzzle

It is around that time that angiosperms (flowering plants) began to develop. They produced flowers and fruits that contained seeds and evolved from shrubs and trees or gymnosperms. How they did, it was Darwin’s largest puzzle. He was afraid that it would undermine the rest of his theories. The new study aims at solving this puzzle more than a century after his death.

A few hundred newly described specimens from fossils shine a new light on the history of flowers. According to Google Shi, lead study author, and professor at the Nanjing Institute of Geology, the specimen was extracted from fossilized peat and date to the early cretaceous in Inner Mongolia.

Good preservation enabled the scientists to recreate the green bracts, flowering leaves, brown seeds, and vivid blue stalked cupules. The leaves may have been fed on by the Yutyrannus huali and the Zhenyuanlong suni: two types of dinosaurs. Prehistoric mammals, including the repenomamus, the beast which feasted on dead dinosaurs, might have also snacked on the leaves.

She continues to say that the reproductive structures show defining angiosperm-like features. They include a cup-shaped structure that encloses fruits such as the acorn and a backward bending cupule.

The team employed a technique called phylogenetic analyses that is akin to piecing together a plant family tree. They compared the extinct seed plants with those from 66 to 252 million years ago.

The bulk of the dataset confirmed similar morphological and anatomical properties. In addition, it showed a remarkable resemblance to modern flowering plants.

The flowering plants are known to have arisen from an ancestor in the gymnosperms. However, there are many in the fossil records, making it unclear which one was responsible.

How the researchers linked the two groups

The new plants, which researchers categorize as angiophytes, are very closely related to modern angiosperms and give clues to their origin. In addition, they display extraordinary diversity in their reproductive structure shapes.

Angiosperms are the carpel (the female reproductive part that hosts one or more ovules) and the cupule’s outer layer. Shi adds that the outer layer is a characteristic of angiosperms not seen in other seeding plants.