Carcharhinus cf. amblyrhynchoides ( Whitley, 1934 )

Jirapatrasilp, Parin, Cuny, Gilles, Kocsis, László, Sutcharit, Chirasak, Ngamnisai, Nom, Charoentitirat, Thasinee, Kumpitak, Satapat & Suraprasit, Kantapon, 2024, Mid-Holocene marine faunas from the Bangkok Clay deposits in Nakhon Nayok, the Central Plain of Thailand, ZooKeys 1202, pp. 1-110 : 1-110

Carcharhinus cf. amblyrhynchoides ( Whitley, 1934)

Fig. 18 A – E

cf. Gillisqualus amblyrhynchoides Whitley, 1934: 189 – 191 , text-fig. 4. Type locality: Cape Bowling Green, Queensland.

cf. Carcharhinus amblyrhynchoides . Compagno 1984: 458 – 459, with in-text figs. Krajangdara et al. 2022: 49, with in-text figs.

Referred material.

CUF - NKNY - S 3 - 2 (Fig. 18 A – E ) (1 upper tooth).

Description.

The crown of CUF - NKNY - S 3 - 2 is triangular and erect with fine serrations and displays well-developed heels mesially and distally. Its lingual face is distinctly more convex than the labial one. Its base presents a damaged lingual face.

Habitat.

Tropical, inshore and offshore, coastal-pelagic species, found over the continental and insular shelves ( Compagno 1984).

Distribution.

Gulf of Aden and Indian Ocean; Indo-West Pacific, from southern China to Australia ( Compagno 1984).

Record in Thailand.

Gulf of Thailand and Andaman Sea ( Compagno 1984; Krajangdara et al. 2022).

Taxonomic remarks and comparisons.

The specimen CUF - NKNY - S 3 - 2 represents an anterior upper tooth. Several species of Carcharhinus have similar upper teeth in terms of morphology. Additional teeth and larger assemblages are needed for a more precise identification. Nevertheless, the tooth most resembles the upper teeth of C. amblyrhynchoides ( Garrick 1982: fig. 20). Male individuals of C. brachyurus have somewhat similar upper teeth ( Garrick 1982: fig. 51), but the mesial cutting edge of their crown is often more convex. Carcharhinus limbatus also shows the same characters, but the serration on the cusps at the base of the crown is much finer ( Bass et al. 1973: pl. 5; Garrick 1982: fig. 18). The pattern of serration also resembles that of the lower teeth of C. sorrah , although in the latter, the base of the root is more concave and the heels of the crown are better developed, the teeth being longer mesio-distally than high baso-apically ( Voigt and Weber 2011). Regarding the fossil record in Southeast Asia, similar teeth have been reported from the Late Miocene deposits of Brunei in Borneo ( Kocsis et al. 2019).

Figures

Figure 18. Carcharhinid shark teeth A – E Carcharhinus cf. amblyrhynchoides, specimen CUF - NKNY - S 3 - 2 in A lingual B labial C mesial D distal and E apical views F – J Carcharhinus cf. amblyrhynchos, specimen CUF - NKNY - S 3 - 10 in F lingual G labial H mesial I distal and J apical views.