Brazilian paleobotany has just made an exciting breakthrough: the reclassification of a fossil plant discovered decades ago in southern Brazil, leading to the establishment of a new genus called Franscinella. The species is now known as Franscinella riograndensis (Salvi et al.) Carniere, Pozzebon-Silva, Guerra-Sommer, Uhl, Jasper et. Spiekermann comb. nov. This research is part of Júlia Siqueira Carniere’s master’s thesis, who is now a doctoral student in the Graduate Program in Environment and Development at Univates (PPGAD). The findings were recently published in the scientific journal Review of Palaeobotany and Palynology. The study reinterprets material previously classified as Lycopodites riograndensis and documents the first instance of lycopodites with in situ spores found in the Permian strata of the Paraná Basin.
This discovery not only redefines its original classification but also provides a potential solution to a scientific puzzle that has lasted over 50 years: the search for in situ plant spores preserved in Upper Paleozoic clastic rocks (between 298.9 million and 252.17 million years ago) in Brazil. This remarkable achievement was made possible through advanced methodologies and a collaborative effort between prominent Brazilian institutions.
A fresh perspective on an old fossil
The species Lycopodites riograndensis was initially described based on its general macro-morphological features without detailed information about its anatomy or spores. Earlier analyses were limited to observed shapes and stem arrangements, lacking the advanced techniques we have access to today.
Thanks to advancements in microscopic preparation and analysis, researchers from the University of Vale do Taquari — Univates, as part of the Graduate Program in Environment and Development (PPGAD), chose to revisit the original fossil material stored in the Univates Paleontological Collection. Their goal was to explore whether modern methodologies could yield new anatomical and palynological insights.
The research utilized scanning electron microscopy (SEM), vinyl polysiloxane silicone molding (VPS), and transmitted light microscopy, allowing them to visualize both exterior and internal structures with incredible detail. These techniques uncovered crucial features that supported the taxonomic redefinition, including isotomic branching in the stems—a trait associated with certain fossil lycopsids, well-preserved tracheids in the vascular cylinder, and in situ trilete spores displaying verrucate sculpture, all still retained within the plant’s reproductive structures.
Recovering the in situ spores was a complex yet decisive step. The solution came from the itt Oceaneon Technological Institute at the University of Vale do Rio dos Sinos (Unisinos), which specializes in extracting microfossils like pollen, spores, and marine organisms. The itt Oceaneon team implemented a successful protocol tailored for recovering spores in situ.
Connecting the dots: from micro to macro
The spores found in Franscinella riograndensis have a morphology that aligns with the palynological genus Converrucosisporites, which is prevalent in Permian deposits within the Paraná Basin. This link is significant, as it directly connects the macrofossil record (the visible parts of the plant) with the microfossil record (the spores and pollen), helping researchers gain a fuller picture of past vegetation and ecosystems.
This integration allows scientists to generate more comprehensive interpretations of Permian plant communities, blending insights from various lines of evidence. Furthermore, it enhances biostratigraphy studies that utilize fossils to date and correlate sedimentary rock layers.
Why is this discovery noteworthy?
The reclassification of Franscinella riograndensis highlights the potential of revisiting known fossils with modern tools to uncover groundbreaking insights. Many fossil groups, including lycopodids, were traditionally classified under broad genera like Lycopodites due to a lack of detailed information. However, these classifications often shift as new data comes to light.
From a paleobotanical perspective, finding lycopsids with in situ spores in the Paraná Basin paves the way for a richer understanding of Permian flora and the evolution of vascular plants. Globally, this research adds to our knowledge of the diversity and distribution of herbaceous lycopsids during the Permian in Gondwana, representing only the fifth known record of this occurrence, making it a remarkable find. It also opens up avenues for comparing similar records from other parts of the world, enhancing our understanding of these plant groups’ evolution and ecology during the Paleozoic.
The collaboration behind the research
This research was spearheaded by scientists from Univates, with significant contributions from the itt Oceaneon team at Unisinos in the palynological preparation. Collaborations also involved the Federal University of Rio Grande do Sul (UFRGS) and researchers from international institutions, including Senckenberg in Germany. The project was supported by technical assistance from Tecnovates (Univates Science and Technology Park) and received funding from key Brazilian scientific development agencies, including the National Council for Scientific and Technological Development (CNPq) and the Coordination for the Improvement of Higher Education Personnel (CAPES).
Glossary
Paraná Basin — A large sedimentary basin encompassing parts of Brazil, Paraguay, Uruguay, and Argentina, containing rocks from various geological periods.
Biostratigraphy — A geology branch that employs fossils to correlate and date layers of sedimentary rocks.
Converrucosisporites — A palynological genus based on the morphology of specific fossil spores.
Verrucate sculpture — A surface texture of spores or pollen marked by rounded, wart-like projections.
Trilete spores — Spores characterized by a “Y” shaped mark from the cell division process during spore formation.
Gondwana — A supercontinent that existed from the end of the Paleozoic to the Mesozoic, grouping the current Southern Hemisphere continents, including South America, Africa, Antarctica, Australia, and India.
In situ — A Latin term meaning “in the original place”; in paleobotany, it indicates that the microfossil is preserved in its original position.
Lycopods (Lycopsida) — A group of primitive vascular plants that includes modern representatives like Selaginella and Lycopodium, and were much more diverse in the past.
Type material — The set of fossils or specimens used to officially describe a new species.
Transmitted light microscopy — A technique that utilizes light passing through a sample to reveal its internal structures.
Scanning electron microscopy (SEM) — A method that employs a beam of electrons to produce high-resolution images of a sample’s surface.
Vinyl polysiloxane silicone (VPS) molding — A process for creating detailed molds of surfaces, commonly used in dentistry.
Upper Paleozoic — A division of the geological time scale covering the Carboniferous and Permian periods, approximately 359 to 252 million years ago.
Palynomorphs — Microfossils from organic sources, such as pollen grains, spores, and some algae.
Clastic rocks — Sedimentary rocks formed through the accumulation and compaction of fragments (clasts) from pre-existing rocks or minerals.
Summary: Brazilian researchers have redefined a fossil plant from the Permian era by establishing a new genus, Franscinella, and species, Franscinella riograndensis. This significant finding, which links macro and micro fossil records, enhances our understanding of past ecosystems. Utilizing advanced microscopy and interdisciplinary collaboration, the researchers unearthed in situ spores, offering novel insights into the evolution and diversity of ancient vegetation.
