Squatina sp.

Adolfssen, Jan S. & Ward, David J., 2015, Neoselachians from the Danian (early Paleocene) of Denmark, Acta Palaeontologica Polonica 60 (2), pp. 313-338 : 322-323

Squatina sp.

Fig. 3I–J .

Material.—Four teeth collected from the Ce of Stevns Kridtbrud (MGUH 29836, MGUH 29837, GMV2012-64 [batch number]) and a few specimens in private collections from the Br2 of Faxe.

Description.—Monocuspid teeth with a long narrow elongat- ed main cusp with continuous cutting edges. The shoulders are almost horizontal and long and low. The labial face of the crown is convex and smooth, with a well-demarcated apron that projects below the basal face of the root. The lingual face of the crown is strongly convex and smooth. The labial face of the root is low and wide and the basal face of the root is flat. The lingual face of the root has a protuberance with a foramen and several foramina below the crown-root junction on the shoulders.Teeth reaching 2.7 mm in height and 3 mm in width.

Remarks.—The separation of individual species of Squatina is extremely difficult ( Dalinkevičius 1935; Cappetta 1987; Rees 2005). Squatina cranei ( Woodward 1888) and S. decipiens ( Dalinkevičius 1935) from the Late Cretaceous and earliest Paleocene were demonstrated to be synonyms ( Guinot et al. 2012), the former being based on the teeth of juveniles and the latter, adults. This species demonstrates a higher degree of heterodonty than seen in Recent Squatina and was therefore placed in a separate subgenus, Cretascyllium Guinot et al. 2012 . It is probable that these specimens belong to S. cranei , however, while evidence of the heterodonty is absent from these specimens, they are better left in open nomenclature.

Stratigraphic and geographic range.— Squatina ranges from the late Jurassic to Recent, Worldwide. It is most likely that it will be subdivided into separate genera or subgenera.

Figures

Fig. 3. Hexanchiformes, Squaliformes, and Squatiniformes from the Danian of Stevns Kridtbrud, Kulstirenden, and Faxe kalkbrud. A. Chlamydoselachus sp., MGUH 29828, DK635 (Ce) lateral tooth in labial (A 1), lingual (A 2), and distal (A 3) views. B–E. Squalus gabrielsoni Siverson, 1993. B. MGUH 29829 (Ce) lower anterior tooth in labial (B 1) and lingual (B 2) views. C. MGUH 29830 (Ce) lower lateral tooth in labial (C 1) and lingual (C 2) views. D. MGUH 29831 (Br1) lateral tooth in labial (D 1) and lingual (D 2) views. E. MGUH 29832 (Br1) lateral tooth in labial (E 1) and lingual (E 2) views. F. Squaliodalatias sp., MGUH 29833 (Ce) lateral tooth in labial view (F 1), lingual (F 2), and distal (F 3) views. G, H. Centroscymnus praecursor Müller and Schöllmann, 1989. G. MGUH 29834 (Ce) lower tooth in labial (G 1) and lingual (G 2) views. H. MGUH 29835 (Ce) lower tooth in labial (H 1) and lingual (H 2) views. I, J. Squatina sp. I. MGUH 29836 (Ce) lateral tooth in labial (I 1) and lingual (I 2) views. J. MGUH 29837 (Ce) lateral tooth in labial (J 1) and lingual (J 2) views. K. Parasquatina cappettai Herman, 1982, MGUH 29838 (Ce) tooth in labial view (K ), lingual (K ), and distal (K ) views.