Tortonian fish otoliths from turbiditic deposits in Northern Italy: taxonomic and stratigraphic significance

Abstract Fish otoliths from the fossiliferous turbiditic sand deposits outcropping at the Borelli and Moncucco localities (Piedmont, Northern Italy) are herein analyzed. The studied section is Tortonian in age and belongs to the lower portion of the Sant’Agata Fossili Formation. The study reveals the presence of at least 90 otolith-based taxa of which 78 are identified at the species level. Two of these are named and described as new species: “Gobiida” bicornuta and “Gobiida” brioche . In addition, 19 taxa, including both still living and extinct ones, are recorded for the first time in Tortonian deposits. Among them, the still living Nansenia aff. oblita , ? Sagamichthys schnakenbecki , and Chaunax pictus are found as fossils for the first time. The high diversity of this well-preserved otolith assemblage improves the systematic knowledge of the Tortonian gobiids and other neritic taxa, which show a close affinity with the present-day Mediterranean fauna. Moreover, the stratigraphic distribution of both neritic and mesopelagic taxa, that were previously considered to enter the Mediterranean Basin in younger stratigraphic intervals, can now be extended back to the Tortonian.