Biodiversity of Marine Molluscs from Sambaqui da Tarioba, Rio das Ostras, Rio de Janeiro (Brazil)

Shellmounds are archaeological sites found in almost all coastal areas around the world that have been recognized as artificial constructions dating between 8.000 and 2.000 years B.P. The Sambaqui da Tarioba has a malacological inventory with a total of 47 species. This set of species was accumulated over long periods, therefore, constitute a sample of the past diversity of molluscs in this region. To assess the representativeness of the shellmounds as a sampler of the marine molluscs diversity, data from this archaeological site were compared with present day inventory of molluscs from Rio de Janeiro coast. To describe the malacological diversity, two indices were used: average taxonomic distinctness (AvTD), defined as the average taxonomic path length between any two randomly chosen species, traced through a phylogenetic classification of the full set of species involved and variation in taxonomic distinctness (VarTD), which reveals the evenness of the distribution of taxa across the hierarchical taxonomic tree. The results indicate that the set of species recorded for Sambaqui da Tarioba is able to recover the biodiversity of a random sample of 47 species from the total inventory of molluscs recorded for Rio de Janeiro. This means that the malacological taxonomic diversity recorde