Carcharhinus brevipinna
Müller & Henle, 1839(Fig. 2 A-C)
Carcharhinus brevipinna Müller & Henle, 1839: 31, pl. 9.
REFERRED SPECIMENS. — One isolated upper tooth under the specimen number PUKPS-784. LOCALITY AND HORIZON. — Middle Miocene (Langhian age) greyish coarse sandstone gravelly lag bed of Chhasra Formation at Palasava site, Kutch, Gujarat.
DESCRIPTION
Specimen PUKPS-782 is a small size tooth, crown is triangular in shape, distally inclined, both the mesial and distal cutting edges are finely serrated (Fig. 2 A-C). The serration is slightly coarser towards the median portion of the cusp. The lingual face of the tooth is convex while the labial face is slightly flattened towards the apex, convex at the median portion and slightly concave towards the base of the crown. The mesial edge of the cusp is distally inclined and the distal edge forms a nearly vertical notch to the heel. The crown of the tooth is curved lingually (Fig. 2C). The root is bilobate, wider than the height, with a prominent median groove that separates each lobe and the base of the root is nearly straight to slightly concave. The crown-root boundary is convex. The crown height of the tooth is 2.45 mm, width of the root is 6.76 mm and the total height of the tooth is 4.44 mm.
REMARKS
Carcharhinus brevipinna (Müller & Henle, 1839) is distinguished from other Carcharhinus taxa in having a short cusp with a lingually curved crown (Perez et al. 2017). The upper teeth of C. brevipinna are closely similar to C. limbatus, however it differs in having a shorter cusp, asymmetric crown and finer serration at teeth shoulder (Perez et al. 2017). The upper teeth of C. limbatus are differentiable from C. brevipinna in having coarser serrations at the heels especially at the distal heel (see, Perez et al. 2017). The differentiation of the present specimen into upper or lower tooth is very difficult. However, we prefer to describe it as upper tooth of C. brevipinna, which is often slightly broader (also see Perez et al. 2017). The present specimen resembles to those of C. brevipinna reported from the late Miocene of Lago Bayano, Panama (Perez et al. 2017) in having a shorter and more asymmetric crown, lingually curved towards the apex and extended root. Previously, dermal denticle of C. brevipinna had been reported from the late Miocene deposit of Baripada beds as C. maculipinnis (Sahni & Mehrotra 1981). This is the first report of C. brevipinna from the Miocene sediments of Kutch, India.
Publication Date: 2022-12-14