CONEROICHNUS MARINUS ICHNOGENUS ET ICHNOSPECIES NOV., A FOSSIL TRACKWAY OF MARINE REPTILE IN THE MAIOLICA FORMATION (UPPER JURASSIC-LOWER CRETACEOUS) FROM MOUNT CONERO, MARCHE, ITALY

Abstract

An uncommon ichnofossil, constituted of a sequence of eleven imprints, named as Coneroichnus marinus ichnog. et ichnosp. nov., is described from Mount Conero, Province of Ancona, Italy. The trackway is impressed in whitish micritic limestone of the Maiolica Formation (Upper Jurassic–Lower Cretaceous), herein interpreted as the passage on the sea bottom of a marine reptile, softly interfering in the sediment-water interface. Its gait can be defined as half-swimming, that is the swimming in exploratory and punting propulsive contact with the mud at the bottom. We discuss the probable trackmaker and we suggest it was probably a pliosaurid Plesiosauria. The extreme rarity of ichnofossils of tetrapods on the deep-sea bottom in the whole world is herein confirmed.