OSTRACODS (CRUSTACEA) AND TAPHONOMY AS TOOLS INTEGRATED INTO CONSERVATION PALEOBIOLOGY

Taphonomy is a fundamental tool for understanding the evolution of environments over time, as it allows for a critical analysis of the processes that affect the preservation of fossils. Using taphonomic analyses, it is possible to identify the effects of postmortem alterations, as well as to reconstruct, with greater precision, the environmental conditions that favored, or not, fossilization. In order to understand which processes favor or hinder the preservation of fossils, the present study analyzes paleobiological data from Laguna Tramandaí (RS), southern Brazil. The research is developed through seasonal collections of bottom sediments and boreholes carried out at six fixed points (BG01 to BG06) of the lagoon. The bottom collections were made with a Van Veen dredger, and the sedimentary cores with PVC pipes (50 mm in diameter). Screening and analysis are carried out at the Laboratory of Limestone Microfossils at UFRGS, and ²¹⁰Pb dating was conducted at the Laboratory of Marine Inorganic Chemistry at USP.  A preliminary comparison between the current fauna and the fossil record reveals an interesting pattern. At point BG04, for example, the ostracod species Cyprideis riograndensis, Cyprideis multidentata and Perissocytheridea kroemmelbeini have been found currently. However, the first 40 cm of the sedimentary core do not have preserved carapaces. Nevertheless, historical data from 1984 indicate that, at the same point analyzed in this work, the species C. riograndensis occurred alive