New species of fern 300 million years old discovered

In Portugal, researchers from the Center for Geosciences of the University of Coimbra (CGEO) discovered a fossil that indicated the existence of an ancient plant. Its main feature is the exceptional preservation of spores. The plant was given the name Acitheca machadoi in honor of geologist Gil Machado.

The discovery, made in the geological layers of the Anadia region, belongs to the extinct genus of tree ferns Acitheca. It was part of the Psaroniaceae family. The study was published in the scientific journal Review of Palaeobotany and Palynology.

As paleontologist Sofia Pereira said when commenting on the discovery, we are talking about one of the best-preserved fossils for the genus Acitheca.

“The size of the sporangia (the structures in which spores are produced) suggests the plant may have adapted to a dry climate, which was rare in the Carboniferous period,” she added.

Despite the limited global diversity of the genus Acitheca (less than ten species are known), the discovery of Acitheca machadoi is the third discovery of its kind in Portugal, possibly indicating the underappreciated biodiversity of these ferns.

“The discovery will not only help us look into the distant past, but also better understand how plants adapted to environmental changes in the ancient world,” the researchers said.

Experts clarified that geologist Gila Machado studied the stratigraphy and paleoflora of the Carboniferous in Busaco (located about five kilometers from Luso, a thermal resort with the most popular mineral water in Portugal), where the fossil was discovered.

The history of Busaku reflects the important transition from a humid to a drier climate at the Carboniferous-Permian boundary, when global climate changes began that ended the Paleozoic era.

An archaeological breakthrough was previously reported in England, where some of the oldest tree fossils on the planet were found. In the south of the country, during a survey of Saltern Bay, which is part of the UNESCO global geopark “English Riviera”, so-called lycopsids were discovered. The age of the find, as scientists believe, is about 377 million years. It is known that these ancient plants were similar to palm trees and are the ancestors of the giant trees that once contributed to the formation of coal.

Expedition leader Dr Kevin Page said the fossils were “incredibly important because they provide valuable information about prehistoric environments, including the presence of volcanic islands with trees growing on them.”