Integricardium (Integricardium) bannesianum (Contejean, 1860)

Fuersich, Franz T., Alberti, Matthias, Pandey, Dhirendra K. & Ayoub-Hannaa, Wagih S., 2022, Jurassic bivalves from the Spiti area of the Himalayas, northern India, Zitteliana 96, pp. 153-178 : 153

Integricardium (Integricardium) bannesianum (Contejean, 1860)

Plate 5, fig. 9

1860 Cardium bannesianum Contej. - Contejean: 276, pl. 15, figs 1-5.

1959 Cardium bannesianum Contejean - Jaboli: 59, pl. 7, fig. 9.

1995 Integricardium (Integricardium) bannesianum ( Contejean 1860) - Jaitly et al.: 115, pl. 12, figs 14-18, text-figs 27-28.

Material.

A single right internal mould with remains of shell from the Ferruginous Oolite Formation near Zangla (SNSB-BSPG 2020 XCIX 41).

Description.

Specimen relatively small for the species (H: 32 mm), suborbicular, nearly equilateral, moderately inflated. Margins slightly damaged but anterior and posterior margins apparently regularly rounded, ventral margin broadly curved. Umbo mesial, orthogyrate. With very faint posterior umbonal ridge. Shell surface covered with commarginal growth lines but lacking posterior radial striae.

Remarks.

The latter feature distinguishes species the genus Integricardium from Protocardia . The specimen falls in the range of variation of I. (I.) bannesianum and therefore has been placed in that species. According to Dietrich (1933), the closely related I. (I.) propebanneianum (Dietrich, 1933, p. 50, pl. 6, figs 92-93) differs in possessing, in contrast to I. (I.) bannesianum , a pallial sinus, a stronger posterior umbonal ridge and a less strongly curved ventral margin. A detailed investigation of the type material is required to clarify the relationship of the two species.

Figures

Plate 5. (1 - 6) Pruvostiella (Pruvostiella) hermanni (Oppel, 1863). 1. Crushed articulated specimen from the lower member at Langza (SNSB-BSPG 2020 XCIX 53). a, left valve view; b, dorsal view. 2. Crushed articulated specimen from the lower member close to the pass to Tashigeng (SNSB-BSPG 2020 XCIX 54 a). a, left valve view; b, right valve view. 3. Crushed articulated specimen from the lower member at the Kaza-Hikkim road cut (SNSB-BSPG 2020 XCIX 55 a). 4. Articulated specimen from the lower member at Langza (SNSB-BSPG 2020 XCIX 59 b). a, right valve view; b, left valve view. 5. Articulated specimen from the lower member close to the pass to Tashigeng (SNSB-BSPG 2020 XCIX 54 b). a, right valve view; b, dorsal view; c, left valve view. 6. Crushed articulated specimen from the lower member at the Kaza-Hikkim road cut (SNSB-BSPG 2020 XCIX 55 b). (7) Nicaniella (Nicaniella) cf. polymorpha (Contejean, 1860). Articulated specimen from the lower member at the Kaza-Hikkim road cut (SNSB-BSPG 2020 XCIX 42). a, right valve view, natural size; b, enlarged; c, dorsal view; d, left valve view. (8) Cryptocardia sp. Right internal mould with remains of shell from the lower member close to the pass to Tashigeng (SNSB-BSPG 2020 XCIX 40). (9) Integricardium (Integricardium) bannesianum (Contejean, 1860). Right internal mould with remains of shell from the Ferruginous Oolite Formation near Zangla (SNSB-BSPG 2020 XCIX 41). a, lateral view; b, dorsal view.