Sulcatostrophia Caster, 1939

Ma, Xue-Ping, Becker, Ralph Thomas, Li, Hua & Sun, Yuan-Yuan, 2006, Early and Middle Frasnian brachiopod faunas and turnover on the South China shelf, Acta Palaeontologica Polonica 51 (4), pp. 789-812 : 793-794

Genus Sulcatostrophia Caster, 1939 Sulcatostrophia? bunapica Veevers, 1959a

Fig. 4A .

1912? Orthothetes crenistria Phillips ; Mansuy 1912: 66–67, pl. 12: 3.

1931? Shellwienella crenistria (Phillips) ; Grabau 1931: 20, pl. 1: 2 (Mansuy’s specimen re−illustrated, with English translation of original description).

1959 Nervostrophia bunapica sp. nov.; Veevers 1959a: 65–69, text−figs. 36, 37, pl. 7: 1–8.

Material.—One poorly preserved specimen, with broken margins, sample PY5 (see Fig. 2 ).

Discussion.—This shell has an unequally parvicostellate ornament, with about 6 to 12 radial striae between adjacent costae or costellae. Other features include: hinge entirely denticulate; ventral interarea with 18 vertical ridges per 5 mm; dorsal interarea about 1/2 to 2/5 height of ventral interarea, and chilidium convex and semi−cylindrical, covering entire notothyrium. Nervostrophia has intermittently discontinuous, tear−drop shaped, radial costellae ( Cocks and Rong 2000: 286), which does not allow the assignment of the present species in the genus. The present species is similar in outline and ornament to members of Parapholidostrophia Johnson, 1971 , but differs in having dense radial striae. Internal differences in Veevers’ (1959a) type specimens are the absence of a dorsal median septum and the presence of a longitudinally grooved, bifid cardinal process. Veevers (1959a) equated Sulcatostrophia? bunapica with “ Orthothetes crenistria ” (Phillips, 1836) , described by Mansuy (1912) from eastern Yunnan. Mansuy’s shell is a ventral valve on a slab that does not allow complete comparisons. The studied specimen can be distinguished from Middle Devonian (Givetian) Nervostrophia guanwushanensis Chen in Xu et al. 1978 by its larger size and more numerous striae between adjacent costae or costellae (6–12 versus 3–6). It also differs from Douvillina cf. interstrialis ( Phillips, 1841) described from the Early Frasnian by Xu et al. (1978: 302–307) in that the latter species has a much more transversely oval outline and fewer striae (2–3 in number) between adjacent costae or costellae.

Occurrence.—This species was first described by Veevers (1959a) from the Frasnian Sadler Formation of the Fitzroy Basin, western Australia. The studied specimen is from the Panxi section of eastern Yunnan Province; middle part of the Yidade Formation (approximately the Frasnian Mesotaxis falsiovalis – Palmatolepis punctata zones).

Figures

Fig. 4. Strophomenid and rhynchonellid brachiopods from the Early and Middle Frasnian of the Panxi and Caiziyan sections. A. Sulcatostrophia? bunapica Veevers, 1959a, PUM05001, sample PY5, Panxi section, Middle Frasnian, dorsal (A1), ventral (A2), area (A3) views, and enlargement of framed area in image A1 (A4). B. Phlogoiderhynchus squamosus (Wang, 1956), PUM05002, sample PY3, Panxi section, Early Frasnian, dorsal (B1), lateral (B2), and posterior (B3) views. C. Phlogoiderhynchus depressus (Wang, 1956), PUM05003, sample PY2, Panxi section, Early Frasnian, dorsal view. D. Pugnax cf. triplicata (Chen in Xu et al. 1978), PUM05004, sample GC20, Caiziyan section, Early Frasnian, lateral (D1: ventral beak broken), dorsal (D2), and anterior (D3: left anterior broken, right lateral anterior slightly broken) views. E. Coeloterorhynchus sp., PUM05005, sample GC21−24, Caiziyan section, Early Frasnian, dorsal (E1: right anterior and right lateral broken), posterior (E2), and lateral (E3) views.

Fig. 2. Stratigraphy and distribution of Early and Middle Frasnian brachiopods in South China. Most but not all known brachiopods are described and illustrated in this paper. For the distribution of atrypids in the Dushan section, for example, see Ma et al. (2005). The stratigraphy of Panxi and the occurrence of Cyrtospirifer sp. are based on Yunnan compiling group (1978) and the occurrence of Stringocephalus in the lower part of the Yidade Formation is as in Xian et al. (1988: 148). The stratigraphy of Dushan and the occurrence of Stringocephalus sp. are as in Liao et al. (1979); the Caiziyan section was re−measured by Long−Ming Wei, Xue−Ping Ma, and Hua Li (personal communication 2005), with coral identifications by Wei−Hua Liao. The stratigraphy of Qiziqiao is based on data of Z.−X. Hu and Z.−Q. Deng in Tan et al. (1987), and the occurrence of Yunnanella sp. is based on Zu−Han Liu (personal communication 2001). Abbreviations: calc., calcareous; argill., argillaceous; C., Cyrtospirifer; Pa., Palmatolepis; Po., Polygnathus; S., Spinatrypina.