Pachygaleus lefevrei ( Daimeries, 1891 )

Adnet, Sylvain & Cappetta, Henri, 2008, New fossil triakid sharks from the early Eocene of Prémontré, France, and comments on fossil record of the family, Acta Palaeontologica Polonica 53 (3), pp. 433-448 : 441-442

Pachygaleus lefevrei ( Daimeries, 1891)

Fig. 7A–C .

1891 Galaeus lefevrei sp. nov.; Daimeries 1891: 74 (no figure).

1905 Galeus lefevrei ( Daimeries, 1891) ; Leriche 1905: pl. 11: 54–58.

1946 Eugaleus lefevrei ( Daimeries, 1891) ; Casier 1946: pl. 1: 13.

1992 Pachygaleus lefevrei ( Daimeries, 1891) ; Cappetta 1992: 644–645.

1994 Galeorhinus lefevrei ( Daimeries, 1891) ; Kemp 1994: pl. 16: 7, 8.

1994 Galeorhinus lefevrei ( Daimeries, 1891) ; Case 1994: pl. 8: 165, 166.

1995 Pachygaleus lefevrei ( Daimeries, 1891) ; Bault and Genault 1995: pl. 7: 5, 6, pl. 8: 1, 2.

1999 Galeorhinus lefevrei ( Daimeries, 1891) ; Müller 1999: pl. 5: 2.

1999 Pachygaleus lefevrei ( Daimeries, 1891) ; Kent 1999a: pl. 2.2: P.

Material.—65 teeth.

Description.—This species has been frequently described and illustrated, so detailed treatment here is unnecessary. The teeth are medium sized (up to 10 mm width) with an oblique, compressed crown having generally smooth enameloid. The mesial cutting edge is slightly convex and usually lacks cusplets or serrations, though serrations may occur on some teeth ( Fig. 7B ). The distal heel, very long and oblique, bears numerous well−developed cusplets that become smaller distally. The root is wide, moderately robust, expanding basally in two lobes with rounded extremities. It is overhung by the labial bulge of the crown which may sometimes present irregular wrinkles.

Comments.—The type species was originally described from material of the Saint−Gilles locality ( Belgium, Ypresian) by Daimeries (1891), who attributed it to the invalid genus Galaeus (typological mistake). Cappetta (1992) amended the diagnosis of this species with the description of the new genus Pachygaleus , characterized by the large size and the very peculiar thickness of their teeth. Pachygaleus lefevrei is known from Thanetian to Lutetian deposits of the of the U.S. Atlantic Coast to west European basins including south England, Belgium, northern and southwestern France ( Casier 1946, 1966; Dutheil 1991; Cappetta 1992; Kemp 1994; Bault and Genault 1995; Kent 1999a; Müller 1999; Adnet 2006). As Cappetta (1992) noted, the distribution of this triakid shark seems to have been restricted to the North Atlantic coasts during the Paleogene.

Figures

Fig. 7. Triakid shark Pachygaleus lefevrei (Daimeries, 1891). Prémontré Abbey, late Ypresian. A. UM−PRE 19, anterior tooth, labial face. B. UM−PRE 20, antero−lateral tooth, labial face. C. UM−PRE 21, lateral tooth, labial (C1) and lingual (C2) faces.