Middle Jurassic Monte Fallano Plattenkalk (Campania, southern Italy): first report on terrestrial plants, decapod crustaceans and fishes

Abstract

A new Jurassic fossiliferous Plattenkalk has been discovered at Monte Fallano (Caserta, Campania, southern Italy). Biostratigraphic analyses indicate a Bajocian/Bathonian age (Middle Jurassic). The fossil assemblage consists of terrestrial plants, invertebrates (bivalves, gastropods, decapod crustaceans, isopods and insect larvae) and vertebrates (fishes). This study takes terrestrial plants, fishes, and decapod crustaceans into account, giving systematic, taphonomic and palaeoenvironmental considerations. The land flora consists of impressions of sterile and fertile shoots of microphyllous conifers; leaves with parallel venation of unknown taxonomy are also present. The genera Cupressinocladus, Brachyphyllum and Araucarites are documented and their microscopical characters are examined. Plant remains possibly represent a stable biotope, as floral composition presents no variation along the section studied. Taphonomic considerations on plant fossils suggest parautochtonous deposition. The study of the rich decapod crustacean fauna includes Acanthochirana liburiaensis n. sp. (Aegeridae Burkenroad, 1963), Casertanus sabellicus n. gen., n. sp. (Sergestidae dana, 1852), Eryma osciensis (Erymidae Van Straelen, 1925) and Tethyseryon campanicus n. gen., n. sp. (Eryonidae de Haan, 1841). Casertanus sabellicus n. gen., n. sp. is the oldest representative of Sergestidae in the fossil record, extending the stratigraphic range of this family into the Middle Jurassic. Tethyseryon campanicus n. gen., n. sp. is the earliest species in which juveniles have been identified within the Eryonidae; the presence of both juveniles and adults in the depositional environment of Monte Fallano suggests that this species was autochthonous or parautochthonous. Preliminary data on fossil fishes sample have lead to the identification of leptolepid, macrosemiid among which Notagogus (Neonotagogus) denticulatus, pleuropholid (Pleuropholis) and pycnodontid fishes; other primitive teleosts and incomplete and indeterminate “ganoid” fishes are also reported. Based on the sedimentological data and the characteristics of decapod crustaceans and fishes, the investigated record of the Monte Fallano section represents the product of depositional process in shallow water carbonate platform settings.