Giant scaphitid ammonites from the Maastrichtian of Europe

Journal article

Giant scaphitid ammonites from the Maastrichtian of Europe have generally been assigned to Acanthoscaphites NOWAK, 1911. Prior to the present study, this genus comprised five species: A. tridens (KNER, 1848), A. varians (LOPUSKI, 1911), A. verneuilianus (D'ORBIGNY, 1841), A. sp. of KENNEDY (1987) and A. sp. of KENNEDY and CHRISTENSEN (1997). Of the first-named taxon, material from Aachen-Schneeberg of Early Maastrichtian age, including the specimen illustrated by HOLZAPFEL (1887-89) long thought to have been lost, is described. Recently collected topotype material from Kazimierz Dolny, and from Rejowiec (Poland), of latest Maastrichtian age (Belemnella kazimiroviensis Zone), allows A. varians to be revised. Specimens from the late Early and early Late Maastrichtian of NW Europe, assigned to A. varians, differ consistently in details of ornament, and are assigned to a new subspecies, A. v. blaszkiewiczi n. subsp. Style of ribbing and tuberculation of the varians stock differs from that of A. tridens to such an extent that a new subgenus, Euroscaphites n. subgen., is erected, with varians as type species. The Late Maastrichtian 'Acanthoscaphites' verneuilianus, only known from phragmocones, is provisionally assigned to the new subgenus. The other two species previously reffered to Acanthoscaphites, viz. A. sp. of KENNEDY (1987) and A. sp. of KENNEDY and CHRISTENSEN (1997), both of Late Maastrichtian age, cannot be assigned confidently to either subgenus.

Authors: Jagt, J; Kennedy, W; Machalski, M

• Journal: Bulletin de l'Institut Royal des Sciences Naturelles de Belqique, Sciences de la Terre
• Volume: 69
• Pages: 133-154
• Publication date: 1999-01-01
• ISSN: 0374-6291
• Language: English
• Keywords: Late Cretaceous; New taxa; Europe; Scaphitidae; Ammonoidea