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The study, in which the Institute of Geosciences of the Complutense University of Madrid and the University Lyon-1 have also collaborated, has been directed by the paleobotanist Josep Marmi and has analyzed different environments where he has observed how this group of plants competed in the ancient ecosystems dominated by conifers, ferns and algae.
As Marmi explained, the reconstruction of these plant communities can provide relevant information to find out how dinosaurs adapted to these changes in vegetation and provides information on the causes of their extinction.
“The Mesozoic era is popularly known for the reign of the dinosaurs in all terrestrial environments. It is less known, however, that in the Cretaceous period - the last of this era - there was a true biological revolution that changed most of the ecosystems of the emerged lands ”, Marmi stressed.
The study concludes that 140 million years ago the first flowering plants - called angiosperms in botany - appeared in some low-latitude freshwater aquatic environments.
According to Marmi, in a space of 30 to 40 million years they diversified through river floodplains and other open environments and ended up dominating the majority of plant communities on the planet.
The paleobotanist has analyzed, in the regions of Berguedà, Alt Urgell, Pallars Jussà, La Noguera and Ribagorza Aragonesa, sedimentary rocks that were formed during the last six million years of the Cretaceous period, when the dinosaurs became extinct.
From this area it has recovered numerous plant remains that include algae, spores, pollen grains, seeds, leaves, trunks and roots that have been the basis for rebuilding those past plant communities.
The study refutes the earlier belief that flowering plants already dominated all low- and mid-latitude terrestrial environments in the late Cretaceous.
According to Marmi, in some coastal wetland and estuarine floodplain environments in the Pyrenees at the end of this time, flowering plants still competed with ferns and conifers, while aquatic environments were dominated by carophyte algae. , a group of green algae.
The study reveals that the only environments fully dominated by flowering plants were some riverside communities that grew on the banks of rivers.
According to the paleobotanist, the replacement of the oldest plants - dominated by charophytes, ferns and conifers (a group to which the pines, firs, cedars and cypress, among other current species belong) - for the floras dominated by angiosperms, affected most of terrestrial ecosystems, food webs, soil chemistry and atmospheric composition.
“The irruption of flowering plants in ancient ecosystems was a true revolution on multiple levels. This change laid the foundations from which modern terrestrial ecosystems subsequently evolved ”, stated the researcher.
This study has also provided interesting data to understand the climate of the Pyrenean region at the end of the age of the dinosaurs.