Squalicorax cf. intermedius Glückman

Vullo, Romain, Cappetta, Henri & Néraudeau, Didier, 2007, New sharks and rays from the Cenomanian and Turonian of Charentes, France, Acta Palaeontologica Polonica 52 (1), pp. 99-116 : 106

Squalicorax cf. intermedius Glückman in Glückman and Shvazhaite, 1971

Fig. 2F .

Material.—A single isolated tooth (UM PDI 1) from Le Puits des Insurgés, Madame Island, Upper Cenomanian, unit D, lithological level Dm.

Description.—This tooth is broader than high and rather thick. The cusp is sharp and distally inclined at an angle of about 45 °. The mesial cutting edge is relatively straight, with a light concave sinuosity on its lower third. The distal cutting edge is rectilinear and oblique. The distal heel is not very high and slightly convex. The cutting edges are rather strongly but regularly serrated. The distal notch makes an angle of about 90 °. In profile view, the tooth is clearly concave labially. The labial face of the crown overhangs the root by a strong and salient bulge cut out by some irregular foraminae that are larger medially. The root is thick and very well separated lingually from the crown; its lingual face shows three irregularly placed foramina.

Remarks.—By its size and morphology, our specimen can be related to the Squalicorax falcatus “species−group”. This “group” probably contains numerous undescribed species and requires revision, out of the scope of this article. One species has been described from the Upper Turonian of western Kazakhstan, S. intermedius Glückman in Glückman and Shvazhaite, 1971. The original illustration is rather poor but a dozen of well preserved specimens from Kazakhstan have been studied by one of us (HC). Our specimen shows a dental morphology that is similar to S. intermedius , especially in respect to the basal labial bulge of the crown. In S. cf. intermedius , however, the cutting edges of the cusp, and particularly the distal one, are straight, when they are clearly convex in S. intermedius .

Figures

Fig. 2. Teeth of the hemiscylliid Almascyllium Cappetta, 1980a, the ginglymostomatid Cantioscyllium Woodward, 1889, the cretoxyrhinid Archaeolamna Siverson, 1992 and the anacoracid Squalicorax Whitley, 1939 from the Cenomanian and Turonian of Charentes, SW France. A. Almascyllium sp., Font−de−Benon, Lower Cenomanian; labial view of UM FBN 1. B. Cantioscyllium cf. decipiens Woodward, 1889, l’Amas, Upper Cenomanian; labial (B1), and occlusal (B2) views of UM AMA 1. C. Archaeolamna sp., l’Amas, Upper Cenomanian; labial (C1), and lingual (C2) views of UM AMA 2. D. Squalicorax baharijensis Stromer, 1927, Le Mas, Upper Cenomanian; labial (D1), and lingual (D2) views of UM LMS 1. E. Holotype of Squalicorax coquandi sp. nov., Port−des−Barques, basal Turonian; labial (E1), distal (E2), and lingual (E3) views of UM PDB 1. F. Squalicorax cf. intermedius Glückman in Glückman and Shvazhaite, 1971, Le Puits des Insurgés, Upper Cenomanian; labial (F1), mesial (F2), and lingual (F3) views of UM PDI 1.