The Late Cretaceous belemnite family Belemnitellidae: Taxonomy and evolutionary history

Abstract

The Late Cretaceous belemnite family Belemnitellidae Pavlow, 1914 occurs only in the Northern Hemisphere and includes nine genera and two subgenera: Praeactinocamax Naidin, 1964b, Actinocamax Miller, 1823, Belemnocamax Crick, 1910, GonioteuthisBayle, lS7S,BelemnellocamaxNaidin, 1964b,Goniocamax Naidin, 1964b, Belemnitella d'Orbigny, 1840, Belemnella (Belemnella) Nowak, 1913, Belemnella (Pachybelemnella) Schulz, 1979, Belemnella (Neobelemnella) Naidin, 1975 and Fusiteuthis Kongiel, 1962. The latter is most likely a nomen dubium. Diagnoses of the genera and subgenera are provided. The origin of the family is poorly known. The number of genera and subgenera, fluctuated during the Late Cretaceous. It was one to two in the Cenomanian, increased gradually to a maximum of six in the Early Santonian, decreased gradually to one during most of the Late Campanian and increased to two or possibly three in the Maastrichtian. The belemnitellids occur in the North European and North American palaeobiogeographical Provinces of the North Temperate Realm, in additon to the northern European margin of the Tethyan Realm. The centre of evolution lay in the North European Province and all known genera and subgenera occur there. Species of five genera and two subgenera occur on the northern European margin of the Tethyan Realm and the majority of these are conspecific with species from the North European Province. Species of essentially two genera occur in the North American Province and these are endemic, with a few exceptions.