Perigeyerella costellata Wang, 1955

Chen, Zhong-Qiang, Campi, Monica J., Shi, Guang R. & Kaiho, Kunio, 2005, Post-extinction brachiopod faunas from the Late Permian Wuchiapingian coal series of South China, Acta Palaeontologica Polonica 50 (2), pp. 343-363 : 350

Perigeyerella costellata Wang, 1955

Figs. 7B, C, 8 .

Perigeyerella costellata n. sp.; Wang 1955: 102–103, pl. 6: 1–10. Perigeyerella costellata Wang ; Feng and Jiang 1978: 239, pl. 87: 1. Perigeyerella costellata Wang ; Liao 1980a: pl. 2: 28. Perigeyerella costellata Wang ; Liao 1980b: pl. 2: 10, 11. Perigeyerella costellata Wang ; Xu and Grant 1994: fig. 13. Perigeyerella costellata Wang ; Zeng et al. 1995: pl. 1: 13, 14.

Locality and horizon.—Daijiagou section; 1 st member of the Lungtan Formation.

Material.— NMV P309619–620.

Remarks.—The materials examined agree perfectly with Wang’s (1955) description of the species. This species is defined by its transversely oval to subcircular outline, conical ventral umbo, and rectimarginate anterior commissure. Its external surfaces are weakly rugose and multicostellate, about 35 costellae in 10 mm at the midlength of the shell. Two thin, high dental plates are convergent toward the valve floor ( Fig. 7). The Changhsingian Perigeyerella altilosina Xu and Grant, 1994 is the most closely allied species to P. costellata , from which the Changhsingian species is differentiated by its more elongate outline and proportionally higher ventral interarea. A transversely oval outline and a low ventral interarea of our specimens also recall those of P. tricosa Grant, 1976 , but the loss of a dorsal median sulcus distinguishes Grant’s species from P. costellata .

Figures

Fig. 8. Reconstruction of ventral interior of Perigeyella costellata Wang, 1955 (based on specimen NMV P309620).