Carcharhinus cf. leucas (Valenciennes, 1839)

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. leucas (Valenciennes, 1839)

Fig. 19

cf. Carcharias (Prionodon) leucas Valenciennes in Müller & Henle, 1839: 42 – 43. Type locality: Antilles.

cf. Carcharhinus leucas . Compagno 1984: 478 – 481, with in-text figs. Krajangdara et al. 2022: 52, with in-text figs.

Referred material.

CUF - NKNY - Q 04 (Fig. 19 A – I ), CUF - NKNY - SA- 1 (Fig. 19 J – N ), CUF - NKNY - SB- 3, CUF - NKNY - SC- 5 (4 upper teeth).

Description.

Crowns show well-developed serrations, becoming larger and more complex in the basal part of the distal side of the crown. In labial or lingual view, the mesial side is almost straight, whereas the distal one is concave in its lower third. The outline of the base of the crown is more concave on the lingual face than on the labial one. The root is deep, slightly concave at its base, and does not display a nutritive groove in lingual view.

Habitat.

Close inshore in reef-associated marine habitats, mostly in water less than 30 m depth ( Compagno 1984; Krajangdara et al. 2022).

Distribution.

Cosmopolitan in tropical and subtropical seas, but also reported from estuaries and rivers, tolerant of freshwater conditions ( Compagno 1984).

Record in Thailand.

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

Taxonomic remarks and comparisons.

Teeth of C. amboiensis are very similar to those of C. leucas so that it is very difficult to differentiate them ( Kocsis et al. 2019). As a result, ten incomplete teeth may belong either to C. leucas or C. amboiensis : CUF - NKNY - S 2 - 1, CUF - NKNY - S 3 - 9, CUF - NKNY - S 5 - 1, CUF - NKNY - S 5 - 5, CUF - NKNY - SA- 6, CUF - NKNY - SB- 2, CUF - NKNY - SC- 10, CUF - NKNY - SD - 7, CUF - NKNY - SE- 3 and CUF - NKNY - SE- 9.

Figures

Figure 19. Carcharhinid shark teeth - Carcharhinus cf. leucas A – I specimen CUF - NKNY - Q 04 in A lingual B labial and C – F different apical views G – I close-ups on the serrations of the distal cutting edge at the level of G distal heel and mesial cutting edge at the level of H upper part of the cusp and I heel. J – N specimen CUF - NKNY - SA- 1 in J lingual K labial L mesial M distal and N apical views.