150 years after its discovery, the largest flower trapped in amber reveals its secrets

150 years after its discovery, the largest flower trapped in amber reveals its secrets

Usually ambers are empty. Sometimes, we find trapped insects there – starting point of the cult film “Jurrasic Park” – but it is rare to discover flowers. In 1872, however, a researcher stumbled upon the biggest flower ever trapped in an amber…and identified it a bit quickly. A study published this Thursday in the journal Nature reveals his true identity. A discovery that provides new information on ecosystems and natural environments around 35 million years ago.

150 years of error

It all started in the 19th century, when a Prussian researcher, Robert Caspary, studied this specimen of amber X4088, from Sambia, a peninsula in the Russian enclave of Kaliningrad known for its open-air amber mines. . This is a double rarity: only 1% to 3% of inclusions in Baltic amber from the end of the Eocene are of botanical origin (between -38 million and -33.9 million years ago). But above all, it is the smallest flower included in an amber ever observed, with its 28 mm in diameter and its five petals. Usually, this kind of fossils do not exceed 10 mm.

In his study, he identifies it as Stewartia kowalewskii – a genus that still exists today and belongs to the tea family – but his work is not accompanied by a drawing. The plant is only briefly described there as “a well-preserved pentamerous corolla 28 mm in diameter with the stamens attached”.

A careful study

Eva‑Maria Sadowski and Christa‑Charlotte Hofmann, the two researchers in the study, have therefore more recently taken an interest in this extraordinary fossil. To study the trapped flower in detail, the authors first analyzed its shape. The 28 mm diameter flower is open, the stamens are numerous, almost as long as its five petals. They wanted to extract a sample of pollen to know in detail the species. “I used a scalpel and carefully scraped the pollen from the amber matrix. I was very careful and only scratched the surface, without damaging the precious inclusion. We were able to show with our study that the specimen belongs to Symplocos and not to Stewartia”, develops Eva‑Maria Sadowski.

“The rarity of such inclusion of large flowers is likely due to the size of the resin outpouring and its properties, which could affect the embedding of plant organs,” the researchers explain in the paper. .

This species of flower is found mainly in the present-day forests of East and Southeast Asia. “This is consistent with the most recent analyzes of the so-called Baltic Amber Forest, where probably humid and warm temperate conditions prevailed. Moreover, the evaluation of other inclusions shows that the Baltic amber forest was heterogeneous,” the authors continue in the article. Who would like, after this find, to continue to study the same type of inclusions, but betting on a non-destructive imaging technique, advanced X-ray tomography.