Paleoenvironmental Reconstruction Through Phytolith Analysis in the Casa Da Pedra Shellmound Archaeological Site, São Francisco Do Sul, Santa Catarina, Brazil

Abstract Shellmounds, or middens, are artificial accumulations constituted by food remains, sediments, artifacts, and vestiges of daily life and funerary rituals, and built by groups of fishermen-hunter-gatherers. These archaeological sites contain groups of organisms representative of the fauna and flora existing at the time they were formed, enabling the recovery of paleoenvironmental aspects related to species biodiversity and biogeography, studies with 14 C dating, and analysis of changes in the patterns of marine biodiversity and ocean circulation. This paper uses the Casa de Pedra Shellmound under rock, located in São Francisco do Sul, Santa Catarina, to infer aspects of the paleoenvironment through analyses of phytoliths extracted from the archaeological matrix of the site. The material presents a good quantity of well-preserved phytoliths and sponge spicules. Among the phytoliths, those from grasses predominate with the presence of some trees and palms, with no variation in vegetation type during the period of site occupation, between 5,470 and 4,460 years BP. Despite the vegetation stability, a small densification of the tree cover was identified from the base to the top, which may be related to an increase in humidity, and is in agreement with other paleoenvironmental studies carried out in the southern region of Brazil.