Early Pleistocene shallow marine decapod crustaceans fauna from Fabro Scalo (western Umbria, central Italy): taxonomic inferences and palaeoenvironmental reconstruction

A decapod crustacean fauna from the Gelasian-Calabrian sands of San Lazzaro quarry, Fabro Scalo, (Terni, Umbria, central Italy) is reported. The studied specimens have been assigned to Calliaxina cf. C. punica (DE SAINT LAURENT & MANNING, 1982) (CALLIANASSIDAE DANA, 1852), Pagurus sp. (Paguridae LATREILLE, 1802), Petrochirus sanctilazzari n. sp. (Diogenidae ORTMANN, 1892) and Ranina propinqua RISTORI, 1891 (Raninidae DE HAAN, 1839). Ranina propinqua, previously described from the "Pliocene" of Citta della Pieve (Perugia, Umbria), is re-described and compared with the other Italian Ranina species. Calliaxina cf. C. punica, already known from the early Pliocene of Tuscany, is reported for the first time from the early Pleistocene record of Umbria. Petrochirus sanctilazzari n. sp. is the youngest species of this genus in the fossil record from the Mediterranean area. The discovery of decapod crustaceans from Fabro Scalo enlarges the very scarce knowledge on fossil decapod communities and their distribution in the palaeo-Mediterranean from the Pleistocene of central Italy. The available sedimentological and biostratigraphical data allow an updating of the original specimen described by riStOri to the early Pleistocene. As the Citta della Pieve and Fabro Scalo areas belong to the same geological and palaeoenvironmental scenery, palaeoecological and sedimentological inferences about the documented decapod fauna are proposed.