The belemnite family Holcobelidae (Coleoidea) in the European Jurassic: systematics, biostratigraphy, palaeobiogeography and evolutionary trends

The belemnite family Holcobelidae GUSTOMESOV, 1977 is revised, based on ca. 200 rostra from recent fieldwork as well as historical museum collections. The studied specimens originate from various European localities and are dated from the Early Aalenian to the Early Bajocian (Middle Jurassic). Eight species of the genera Holcobelus STOLLEY 1927 (including H. elmii n.sp.) and Calabribelus nov. gen. (with type species C. pallinii) are described. The evolution of the morphological characters at the family level is outlined and compared with acrocoelitids (Belemnitina) and pachybelemnopseids (Pachybelemnopseina); the possible phylogenetic links between the Holcobelidae and the latter are discussed. The stratigraphic and palaeobiogeographic distribution of holcobelids is analysed in respect to morphological changes, leading to a hypothesis on different lifestyles among the investigated taxa.The peculiar distribution pattern of Holcobelidae represents a colonization event by belemnites in the northern Tethys and a distinctive belemnitid Tethyan fauna developed during the Bajocian, dominated by Pachybelemnopsis and Hibolithes.