Researchers from the University of Coimbra have uncovered a fossil of a new fern species, named Acitheca machadoi, in Anadia, Aveiro, Portugal. This remarkable finding, dating back 300 million years, showcases three-dimensional preserved sporangia with spores still in place, providing vital insights into ancient plant life and climate conditions.
The fossil belongs to the extinct family Psaroniaceae and is characterized by its elongated sporangia. The discovery was made in the geological formations of Anadia by the Center for Geosciences (CGEO) team, led by paleobotanist Pedro Correia.
Notably, Acitheca machadoi is dedicated to Gil Machado, a specialist in Paleozoic palynology, who has extensively studied the stratigraphy of the Carboniferous Basin of Buçaco, where the fossil was found. This exceptional preservation is rare in the fossil record, particularly within the Carboniferous period.
Co-author Sofia Pereira suggests that the small size of the sporangia may indicate adaptations to drier conditions during the Carboniferous period. This reflects a broader trend of climate change, marking the transition from wet to dry conditions that began in this geological era.
With fewer than ten known species globally, the discovery of Acitheca machadoi in Portugal raises questions about the potential underestimation of its diversity worldwide. The findings were published in the journal Review of Palaeobotany and Palynology.