Scientists have discovered fossils of trees in a forest dating back 290 million years, before the arrival of the dinosaurs, in the Brazilian state of Parana (south), a “window to the past” to study the evolution of plants.
The discovery of this fossilized forest of 164 lycophyte trees (without fruits, flowers, or seeds) of an already extinct variety is “the most important in the southern hemisphere” in terms of quantity and quality of preservation, explains Thammy Mottin, geologist from the University of Parana.
“These plants, whose age is estimated at 290 million years, represent very primitive life forms in the history of the earth”, continues this scientist, who carried out her research in partnership with the universities of Rio Grande. do Sul (southern Brazil) and the University of California at Daves, USA.
This forest, which grew near the places where the town of Ortigueira is today, “shows how the first plants spread, how they were distributed in space and what their interactions were” with other forms of life.
A few rare similar discoveries have taken place in the southern hemisphere, notably in the state of Rio Grande do Sul or in Argentine Patagonia, but all of much smaller dimensions.
The fossilized forest of Parana was discovered at the end of 2018, by chance, during geological studies for the layout of a road to a factory.
A long-term study was then launched and the results, published in February in the scientific journal “Palaeogeography, Palaeoclimatology, Palaeoecology”, of the Dutch group Elsevier, were popularized recently in the Brazilian press.
The exceptional preservation was made possible because the trees “were buried when they were still alive, then gradually covered with sediment,” explains Thammy Mottin.
The forest was then “kept almost as is” after being covered by a flooded river that froze.