Palaeohypotodus aff. bronni (Agassiz, 1843)

Adolfssen, Jan S. & Ward, David J., 2015, Neoselachians from the Danian (early Paleocene) of Denmark, Acta Palaeontologica Polonica 60 (2), pp. 313-338 : 328-329

Palaeohypotodus aff. bronni (Agassiz, 1843)

Fig. 6J–L .

Material.—One anterior and one posterior tooth from the Ce of Stevns Kridtbrud (MGUH 29855, MGUH 29856) and one anterior tooth from the Br1 of Karlstrup kalkgrav (MGUH 298457).

Description.—An anterior tooth with a strongly elongated erect main cusp flanked by a pair of small but thick, acute, inwardly twisted cusplets. The labial face of the crown is convex and smooth with a large triangular sulcus originating from the base of the main cusp and reaching almost a third of the cusp length. The lingual face is strongly convex and smooth without any signs of folds or ornamentation. The crown is slightly sigmoid in lateral view and the cutting edge is prominent and reaches the base of the cusp, but is not continuous with the cusplets. The root is almost absent and cannot provide any useful information. The tooth measures 28 mm in height and 15 mm in width. Posterior teeth are low, with a triangular cusp and cusplets and carry strong irregular folds at the crown-root boundary.

Remarks.—These teeth correspond reasonably to those of Palaeohypotodus . Maastrichtian teeth of P. bronnii (Agassiz 1843) often have basal striation or folds on the labial crown base and often two pairs of cusplets. However, the latter has not been observed in these specimens. Because of this, and the limited material, this determination must be regarded as tentative. The genus Palaeohypotodus is kept within Odontaspididae , following Cappetta (1987, 2012).

Stratigraphic and geographic range.—Maastrichtian (Late Cretaceous) of northern Spain ( Kriwet et al. 2007), the Paris Basin ( Priem 1897), Belgium, the Netherlands (Agassiz 1843; Herman 1977; Geyn 1937b), and the north of Germany ( Herman 1982) to the Danian (early Paleocene) of Denmark.

Figures

Fig. 6. Lamniformes from the Danian of Stevns Kridtbrud, Karlstrup kalkgrav, and Faxe kalkbrud. A–C. Carcharias aff. gracilis (Davis, 1890). A. MGUH 29852 (Ce) anterior tooth in labial view. B. MGUH 29853 (Ce) anterior tooth in labial (B) and lingual (B) views. C. MGUH 29854 (Ce) anterior tooth in 1 2 labial (C) and lingual (C) views. D–H. Striatolamia cederstroemi Siverson, 1995. D. OESM-10046-5 (Br2) anterior tooth in labial (D) and lingual (D) 1 2 1 2 views. E. OESM-10046-6 (Br2) anterior tooth in labial (E) and lingual (E) views. F. OESM-10046-18 (Br2) anterior tooth in lateral (F), labial (F), and 1 2 1 2 lingual (F) views. G. OESM-10046-12 (Br2) lateral tooth in labial (G) and lingual (G) views. H. OESM-10046-11 (Br2) lateral tooth in labial (H) and 3 1 2 1 lingual (H) views. I. Odontaspis speyeri Dartevelle and Casier, 1943, OESM-10046-8 (Br2) anterior tooth in labial (I) and lingual (I) views. J–L. Palae2 1 2 ohypotodus aff. bronni (Agassiz, 1843). J. MGUH 29855 (Ce) anterior tooth in labial (J), basal (J), and lateral (J) views. K. MGUH 298457 (Br1) lower 1 2 3 anterior tooth in labial (K ), lingual (K ) views. L. MGUH 29856 (Ce) posterior tooth in labial (L ) and lingual (L ) views.