Micromorphological, geochemical, and diagenetic characterization of sirenian ribs preserved in the Late Miocene paleontological site of Cessaniti (southern Calabria, Italy)

The site of Cessaniti (Vibo Valentia, Italy) has been well known since the 19th century for the richness andgood preservation of its Miocene fauna and flora. The sedimentary succession of the site represents a paralic system that evolved toward an open-marine environment recording the Tortonian transgression. The fossil assemblage containsrich invertebrate (corals, bivalves, gastropods, brachiopods, echinoids, benthic and planktonic foraminifers) and vertebratefaunas (proboscideans, rhinoceroses, giraffids, bovids, sirenids, marine turtles, and fish remains). The fossils recovered at the Cessaniti site have a relevant role in phylogeneticstudies and paleogeographic reconstructions of LateMiocene environments of the southern Italy. This researchis focused on the microstructure and preservation state ofthe fossil bones. Samples of Metaxytherium sp. bones havebeen analyzed to understand the diagenetic profile of thebone assemblages that characterizes the taphonomic history of the Cessaniti site. The analyses provided a comprehensive account of how bone mineral (bioapatite) has been altered and demonstrated that the post-burial processes did not significantly affect the micromorphological and biogeochemicalfeatures of the bones. The excellent preservationstate of the bones strengthens the importance of the Cessaniti site for studies of the Mediterranean Miocene vertebrate fauna.