Pastinachus sp.

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

Pastinachus sp.

Fig. 30

Referred material.

CUF - NKNY - 7.1 (Fig. 30 A – F ), CUF - NKNY - 7.2 (Fig. 30 G – L ), CUF - NKNY - 8.1 (Fig. 30 M – R ) (3 teeth).

Description.

The crown is hexagonal to diamond-shaped in apical view, longer mesio-distally than labio-lingually. The crown surface is rather smooth to heavily pitted. The labial face of the crown displays a salient horizontal bulge. There is a well-developed horizontal groove in the basal part of the crown on the lingual face. The vascularisation of the teeth is holaulacorhize. There is a row of small foramina positioned under the crown on the labial face and between one and four foramina present in the groove separating the two branches of the root in basal view.

Taxonomic remarks and comparisons.

Heavily pitted crowns probably belong to non-functional teeth ( Adnet et al. 2019). Four species of cowtail rays ( Pastinachus ater , P. gracilicaudus , P. solocirostris , and P. stellurostris ) are known in Southeast Asia ( Last et al. 2016), all of them having been recorded in Thai waters ( Krajangdara et al. 2022). Regarding the nearby fossil record, teeth of Pastinachus were reported from India, Taiwan, and Borneo (see discussion in Kocsis et al. 2019).

Class Actinopterygii Klein, 1885

Infraclass Teleostei Müller, 1845

Order Scombriformes Rafinesque, 1810

Figures

Figure 30. Dasyatid ray teeth - Pastinachus sp. A – F specimen CUF - NKNY - 7.1 in A lingual B labial C, F profile D occlusal and E basal views G – L specimen CUF - NKNY - 7.2 in G lingual H labial I, L profile J occlusal and K basal views M – R specimen CUF - NKNY - 8.1 in M lingual N labial O, R profile P occlusal and Q basal views.