Fósseis da formação Ponta Grossa no Parque Vila Velha sob o olhar da divulgação científica

Abstract

The Campos Gerais region in the state of Paraná has a rich record of marine fossils preserved mainly in rocks in the three different cities: Jaguariaíva, Tibagi and Ponta Grossa. This record, internationally known as the fauna of the Malvinokaffric Province, occurs in rocks of the Ponta Grossa Formation with occurrence of invertebrates from the Devonian period, such as brachiopods, trilobites, cnidarians, mollusks, echinoderms, among others. The Ponta Grossa Formation also outcrops in the Vila Velha State Park, a place of natural beauty and great tourist importance in the country, known for its unique rock formation, which also includes other geological units, such as the Furnas Formation and the Itararé Group (Vila Velha Sandstone). The park's fossil record is located on the so-called "Fossil Trail", a site that, although it has a sign indicating marine fossils, does not offer visitors the opportunity to learn about the animals in this important geological context, either due to the poor state of preservation of the specimens that are found inside a wooden enclosure, which has been severely affected by weathering, or due to the lack of information on site, which only shows an image of small shells with no indication of which marine animal it is. Since Vila Velha is a tourist location with a high visitor rate, it would be extremely important, from the point of view of scientific dissemination in paleontology, to provide precise information on the record of Brazilian Malvinokaffric fauna to the thousands of visitors who come to see the park every year. This study’s objective was to verify which fossils from the Ponta Grossa Formation occur in Vila Velha and to prepare scientific dissemination material to contribute precise information on the local fossil record. The study was based on detailed bibliographical research on fossils from the Ponta Grossa Formation and three field studies to collect samples, the specimens of which were analyzed at the Paleontology Laboratory (LAPALEO) of UTFPR, Ponta Grossa campus. A total of 170 samples were collected, and the analyses resulted in the identification of four phyla: Brachiopoda, Molusca (Bivalvia), possibly Cnidaria (Conularidae) and Bryozoa, the latter of which may be the first occurrence in this stratigraphic unit, in addition to Tentaculitoidea. Of the total samples analyzed, 84,8% are Brachiopoda Rhynchonelliformea, 1% are Brachiopoda Linguliformea, 1% are Mollusca, 1,9% Conularidae, 8,6% Bryozoa and 2,9% Tentaculitoidea. The fossil occurrence of Vila Velha State Park is much more diverse than expected, considering that only Brachiopoda were mentioned in a single previous study. Based on the results obtained, a scientific dissemination poster was created on the geological context of the Devonian period, containing images of the fossil animal groups present. After completing this work, there are intentions to propose to the company that manages the park that the poster may be installed as a complementary sign to the one found at the fossil site and thus contribute with more precise information about the Brazil’s Malvinokaffric fauna to a large number of visitors.