Edriosteges poyangensis ( Kayser, 1883 )

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 : 358-359

publication ID	https://doi.org/ 10.5281/zenodo.13620199
persistent identifier	https://treatment.plazi.org/id/03C98792-D32C-2313-FCEB-F875E2E027BA
treatment provided by	Felipe
scientific name	Edriosteges poyangensis ( Kayser, 1883 )
status

Treatment

Edriosteges poyangensis ( Kayser, 1883)

Fig. 13C–G View Fig .

Strophalosia poyangensis n. sp.; Kayser 1883: 190, pl. 28: 8, 10. Aulosteges poyangensis (Kayser) ; Frech 1911: 134, pl. 20: 4a–d. Aulosteges poyangensis (Kayser) ; Chao 1928: 73–74, pl. 3: 23. Aulosteges poyangensis (Kayser) ; Huang 1932: 66–68, pl. 4: 7–13, pl. 5: 25.

Aulosteges poyangensis (Kayser) ; Wang et al. 1964: 345, pl. 56: 2–4. Edriosteges poyangensis (Kayser) ; Sarycheva 1965: pl. 32: 4–6. Edriosteges poyangensis (Kayser) ; Jin et al. 1974: 312, pl. 164: 14. Edriosteges poyangensis (Kayser) ; Zhan 1979: 73, pl. 7: 1–4. Edriosteges poyangensis plena subsp. nov.; Zhan 1979: 73–74, pl. 7: 5–8.

Edriosteges poyangensis (Kayser) ; Liao 1980b: pl. 3: 10–13. Edriosteges poyangensis (Kayser) ; Liang 1990: 148–150, pl. 17: 4, 5.

Locality and horizon: Daijiagou section; 1 st member of the Lungtan Formation; Chuanmu section; 5 th member of the Lungtan Formation.

Material.— Total 15 specimens; figured specimens: NMV P309629–633 About NMV .

Description.—Medium to large shells; outline semicircular in posterior view; slightly transversely trapezoidal in anterior view; hingeline slightly narrower than or equal with shell width; both valves geniculate anteriorly; trails short; ventral interarea relatively low; ears broad, slightly inflated; ventral umbo evenly convex; lateral slopes gentle; median sulcus variously developed, when present, originating anterior to umbo. Dorsal disc concave; median fold indistinct; corpus cavity moderately deep; ventral rugae irregularly spaced, conspicuous on discs, weakening anteriorly, sometime absent on trail; tubercules scatted over valves; spines scattered over ears, ventral corpus and trail, a row along hinge; radial striae fine, prominent when outer shell layer removed; shell thin.

Remarks.—This species is characteristic of the Lungtan Formation in South China. The allied species Edriosteges tumita Liao, 1980b is differentiated from E. poyangensis by an anteriorly convex and strongly geniculated ventral valve. E. subplicatilis Frech, 1911 (see also Liao 1980b: pl. 4: 15–17) is characterized by the presence of more pronounced rugae over the discs, E. acuminata Liao, 1980b is distinct in having the hingeline equal to the maximum shell width and pair of conspicuously projecting ears.