Gen. et sp. indet, BAUR, 1891

Métais, Grégoire, Bartolini, Annachiara, Brohi, Imdad Ali, Lashari, Rafiq A., Marivaux, Laurent, Merle, Didier, Warar, Mashooque Ali & Solangi, Sarfraz H., 2021, First report of a bothremydid turtle, Sindhochelys ragei n. gen., n. sp., from the early Paleocene of Pakistan, systematic and palaeobiogeographic implications, Geodiversitas 43 (25), pp. 1341-1363 : 1358

Gen. et sp. indet . ( Fig. 10 )

EXAMINED MATERIAL. — Fragment of a carapace constituted of two right peripherals with adjacent peripherals and costal parts, CPAG-RANKT-V-4.

LOCALITY. — Lower part of the Khadro Formation of the Ranikot Group, early Paleocene, locality K18-12, in the proximity of Ranikot Fort, Jamshoro District, Sindh Province, Southern Pakistan ( Fig. 1 ).

DESCRIPTION AND COMPARISONS

The specimen (17 cm long × 10 cm wide) includes a right bridge portion of carapace with the posterior part of the peripheral 5, the complete peripherals 6 and 7, with a small part of the peripheral 8, sutured to the lateral end of the costals 3 (part), 4 (complete extremity) and 8 (minimal part). In dorsal view ( Fig. 10B, C ), the peripherals (complete 6 th and 7 th) are wide and display an incurved surface. The free border is thick but neither rounded nor acute. In ventral view ( Fig. 10A ), the posterior extremity of the bridge is positioned at first third of the 7th peripheral. The sutured border of the plates with the plastron is weakly indented to receive the corresponding weak indentations of the hypoplastron. The fragment was colonized by a perforating animal, such as the pholad bivalve, which nested forming rounded cavities. That occurred once the carapace was dislocated in the marine-littoral water ground, because the cavities are distributed as well on the external face, on the periphero-hypoplastral suture and in the inner bridge cavity, being of various sizes.

The fragment is noticeable by its ornamentation, which does not substantially differ from that of S. ragei n. gen., n. sp., being made of wide protruding polygons ( Fig. 10C ) but which are more marked. The polygons are very elongated and well defined and as elongated as in some plates of S. ragei n. gen., n. sp., ( Fig. 8C, E ), but more protruding, perhaps because of a better preservation at this location. The only certitude is that it does not correspond to any other decorated bothremydid examined above by comparison with Sindhochelys . Although similar to Sindhochelys by the marked decoration and different from taphrosphyines and other examined bothremydids from France and India, the fragment remains undetermined.

Figures

FIG. 10. — Fragmentary part of a carapace of an undetermined Bothremydidae, from the Paleocene of Ranikot, locality K18-12, CPAG-RANKT-V4, Southern Pakistan: A, B, ventral and dorsal views; C, detail of the dorsal decoration. Abbreviations: cost3, costal 3; cost5, costal 5; pcs, suture of the peripheral border with the border of plastral processes; per 5-8, peripherals 5, 6, 7, 8; perf, pholad perforations. Scale bars: A, B, 4 cm; C, 1 cm.

FIG. 1. — Location and stratigraphic position of fossil material: A, location of the Laki Range in eastern Sindh Province, southern Pakistan, and simplified geological map of the Ranikot Fort area (adapted from Schelling 1999); B, stratigraphic position of the fossil assemblage within the Waddi Sawri section. Note that the base of this section is close to the base of the Khadro Formation; in this area the thickness of the Khadro Formation is c. 80 m, and the fossil locality K18-12 is in the lower Khadro Formation.

FIG. 8. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Ranikot, locality K18-12, Southern Pakistan. A-D, decoration in various parts of the shell: A, isolated piece with the imprint of the mesoplastral external surface; B, marginal part of peripheral 10, dorsal view; C, left costal 1 part, posterior border at mid-width, dorsal view; D, a costal lateral border, in dorsal view; E, right hyoplastral part, ventral view. Scale bar: 5 cm.