PUC Campinas finds 270-million-year-old fossils
The discovery is considered unprecedented because it demonstrates that the area, which is now part of Brazil, is older than previously thought; the fossils analyzed are from the Permian geological period, when the supercontinent Pangaea was formed (a period when the Earth consisted of a single continent), during which the presence of dinosaurs was not yet recorded.
Renata Giraldi
Reporter from Agência Brasil
Brasilia – Researchers from the Faculty of Biological Sciences at the Pontifical Catholic University (PUC) of Campinas and Unicamp have discovered plant and stem fossils in seven regions of São Paulo, dating back approximately 270 million years. The discovery is considered unprecedented because it demonstrates that the area, which is now part of Brazil, is older than previously thought. One of the articles from the thesis was recently accepted with modifications in the journal... Review of Palaeobotany and Palynology.
The fossils analyzed are from the Permian geological period, when the supercontinent Pangaea was formed (a period when the Earth consisted of a single continent), during which the presence of dinosaurs was not yet recorded.
The conclusion is based on the doctoral thesis of Professor Rafael Souza de Faria, from PUC-Campinas, who worked in conjunction with Professor Fresia Ricardi Branco from the Institute of Geosciences at Unicamp.
“The newly identified specimens show that the diversity of these plants, the conifers, was quite significant in Brazil during the Permian period. The thesis described previously unknown species. Regarding their complexity, they were similar to Araucaria trees and adapted to a dry climate. There is evidence of anatomical characteristics in the plant tissues of these fossils that indicate an adaptation to possible water stress,” Faria told [the publication]. Agency Brazil.
The researchers analyzed the diversity of fossil conifers, similar to araucarias and pine trees, identifying the trees present in seven regions of São Paulo - Piracicaba, Saltinho, Rio Claro, Santa Rosa de Viterbo, Angatuba, Conchas and Laras. Faria and Fresia collected petrified trunks, which they called "permineralized".
According to Faria, it is possible that fossils exist in other regions of the country. "Not only is it possible, but it exists. There are similar fossilized woods in various locations in São Paulo and other Brazilian states that have similar rocks [Permian strata from the package encompassed by the Paraná Sedimentary Basin]," he said.
The research analyzed the lifespan of leaves, known as leaf phenology, to determine how the studied species react over the years. Researchers observed whether the trees lose their leaves (deciduous species) or retain them (evergreen species).
During his studies, Faria also identified the proliferation of fungi in the wood (pieces of wood cut from the tree). He considers this discovery unprecedented in Brazil, as it reflects what he describes as "a moment of difficult times."
“The presence of fungi in fossilized wood is rare. This suggests a collapse of ecosystems, indicating that conditions for the development of conifers were not good during the Permian period,” he said.
“Although we cannot rule out that environmental conditions were different, it is very likely that the trees found lived in an ecosystem that could have been collapsing, hence my calling it 'difficult times', mainly because, in addition to the fungi, there is evidence of adaptation to water stress in the tissues,” he added.