First Mediterranean record of Micropilina minuta Warén, 1989 (Monoplacophora: Neopilinidae)

The lilliputian and elusive monoplacophoran Micropilina minuta Warén, 1989 is recorded for the first time from the Mediterranean basin upon various records of empty shells trawled between 270 and 700 m in the Tuscan Archipelago (northern Tyrrhenian Sea). Our data reveal that Micropilina minuta often co-occurs with the only other monoplacophoran previously recorded in the Mediterranean, Veleropilina reticulata (Seguenza G., 1876).Micropilina minuta Warén, originally described on material from Iceland, was later found in the lower Pleistocene of Archi (Reggio Calabria, Italy). Although some shells are definitely fresh, the absence of live collected specimens leaves open the possibility that the species is no longer living in the Mediterranean Sea.Micropilina minuta differs from V. reticulata for the more ovoidal outline, constricted toward the apex and the presence of about seven deep pits instead of shallow, not well-defined pits, on the apical cup.