Squaliodalatias 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

Squaliodalatias sp.

Fig. 3F .

Material.—A single incomplete lower tooth from the Ce of Stevns Kridtbrud (MGUH 29833).

Description.—This tooth is strongly labio-lingually compressed, with a prominent principal cusp. The slightly triangular cusp has almost straight mesial cutting edge whereas the distal cutting edge is convex. The distal cutting edge and the small convex distal heel join into a notch. The labial face of the crown is slightly convex with a large and flat apron, the extremity of which is bifid, split by the labial marginal foramen and mesially delimited by the interlocking hollow. The lingual face is more convex than the labial face and the uvula is reduced to a small convexity in the crown-root junction. The mesial edge of the root is indented, the basal edge is damaged, but the labial marginal foramen is visible. The basal face of the root is large, labio-lingually concave and separated by the median lingual duct, which is connected to the median lingual foramen. The lingual face is limited to the minor transverse lingual bulge with the central foramen and a small mesio-lingual foramen. The distal lingual interlocking is apicobasally elongated and narrow. The tooth is 1.6 mm wide and 2.6 mm high.

Remarks.—Teeth described as Centrophorus (?) balticus by Dalinkevičius (1935) were referred to Squaliodalatias by Adnet et al. (2006) as were similar specimens from the Paleocene of California ( Welton 1979). There are some differences between the specimens described here and the specimens described by Adnet (2006) and Adnet et al. (2006), Dalinkevčius (1935), and Welton (1979) and the assignment of the above mentioned specimens to the same genus is open to discussion, due to a lack of material.

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.