Extinction and renewal patterns among Tethyan belemnites in the Verrucosum Subzone (Valanginian) of southeast France

• DOI: 10.1006/cres.2002.1019
• Publication Date: 2002-12-28T12:20:15Z
• Authors: Nico M.M. Janssen; Arnaud Clément
• Keywords: Extinction (optical mineralogy); Sequence (biology)

Abstract Significantly higher extinction compared to the normal background extinction is noted among Tethyan belemnites in the ‘Horizon a Neocomiensis’ (the upper part of the Verrucosum Subzone). Several genera and species of belemnites disappear at the base of this deposit. Certain morphological forms are no longer found, i.e., species with conical rostra and relatively deep alveolae. According to our stratigraphical data this extinction event is linked to sequence boundary Va 4 (type-1 sequence). Of general interest is the appearance of the Boreal belemnite Hibolithes cf.jaculoides Swinnerton, 1936 after the extinction event. One new genus, Mirabelobelus, and two new species, M. blainvillei and M. orbignyi, are described based on ‘Belemnites bicanaliculatus’ de Blainville, 1827.