Tescheniceras gen. nov. (Ammonoidea) and the definition of the Valanginian/Hauterivian boundary in Butkov Quarry (Central Western Carpathians, Slovakia)

Jurassic and Lower Cretaceous successions of the Manin Unit Central Western Carpathians are exposed in Butkov Quarry Middle Vah Region, Slovakia. A significant part macrofauna belonging to neocomitid ammonites, formerly classified under genus Teschenites Thieuloy, 1971, occurs deposits spanning Valanginian/Hauterivian boundary. The original definition was accompanied by uncertainties taxonomic stratigraphic position its type species, i.e., Hoplites neocomiensiformis Uhlig, 1902. present contribution focuses on provides a possible solution establishing new Tescheniceras . In Quarry, includes five species. flucticulum (Thieuloy, 1977), is most abundant. callidiscum 1971), subzonal species for uppermost Valanginian (Thieuloy 1971b), only sporadically. Because Acanthodiscus radiatus (Bruguiere, 1789), index basal Hauterivian ( Zone) international ammonite zonation, does not occur locality, indicated first appearance Spitidiscus Kilian, 1910.