Fish otoliths from the Messinian of Strada degli Archi (Tuscany, Italy) - Taxonomy and paleoecology.

The taxonomy and paleoecology of a fish otolith assemblage deriving from the early Messinian terrigenous deposits of the Strada degli Archi section, Fine Basin, Tuscany, have been investigated. The assemblage displays an evident oligotypic character and consists of 11 species-level taxa belonging to five families: Atherinidae, Cyprinodontidae, Gobiidae, Hemiramphidae and Polynemidae. Gobiids strongly dominate the taxonomic structure with seven taxa representing more than 93 % of the specimens examined, followed by atherinids (4.67 %), and cyprinodontids (0.77 %). Hemiramphids and polynemids are extremely rare, both represented by juveniles. The composition of the assemblage indicates a coastal lagoon permanently connected to the sea as the original depositional environment. The analysis of the ecotrophic guilds (ecological guilds, habitat, substratum preference, food preference) has revealed some structural and physiographic features of the original depositional environment, which was possibly characterized by a moderate degree of confinement, a soft and densely vegetated bottom, and a reduced spatial complexity. Finally, the analysis of the stratigraphic distribution of the recognized taxa has revealed that some of them are also members of the late Messinian ‘Lago-mare’ assemblages, implying that structurally similar marine-dependent brackish fish communities possibly occur in the Mediterranean throughout the whole Messinian.