Changshunella yangi Sun, Baliński, Ma, and Zhang, 2004

Sun, Yuanlin & Baliński, Andrzej, 2011, Silicified Mississippian brachiopods from Muhua, southern China: Rhynchonellides, athyridides, spiriferides, spiriferinides, and terebratulides, Acta Palaeontologica Polonica 56 (4), pp. 793-842 : 824-825

Changshunella yangi Sun, Baliński, Ma, and Zhang, 2004

Fig. 24 .

2004 Changshunella yangi gen. et sp. nov.; Sun et al. 2004a: 269–273 , figs. 2–6.

2008 Changshunella yangi Sun, Baliński, Ma, and Zhang, 2004a ; Baliński and Sun 2008: 113–114, fig. 9.

Material.—15 ventral valves and 26 dorsal valves from Muhua III section ( Hou et al. 1985) where it was found in sample MH 1 taken from the base of the Muhua Formation.

Description.—See Sun et al. (2004a) and Baliński and Sun (2008) for detailed descriptions of the genus and species.

Remarks.—This bizarre micro−spiriferid is one of the most interesting discoveries in the Muhua fauna. Its small size and unique external form of the shell, invariably dominated by three very strong and opposed (not alternating) plications on both valves are very characteristic features ( Fig. 24 ). Its length generally does not exceed 4 mm although these shells unquestionably represent mature or even gerontic, individuals. The type of shell plication in C. yangi indicates that it may be close to some other verneuiliid spiriferoids, such as Verneuilia Hall and Clarke, 1893 and Nugushella Tiazheva, 1960. Noteworthy is also a certain external similarity between C. yangi and Scenesia extensa Cooper and Grant, 1976 , the later being described from the Permian of West Texas ( Cooper and Grant 1976: 2756–2758, pl. 724: 36–66) and included by Carter et al. (1994) in the superfamily Paeckelmanelloidea .

Stratigraphic and geographic range.—Known exclusively from the type locality and horizon.

Figures

Fig. 24. Verneuiliid brachiopod Changshunella yangi Sun, Baliński, Ma, and Zhang, 2004 from the Tornaisian Muhua Formation, southern China. A. Ventral valve, PKUM02−0505, in posterior (A1), lateral (A2), and ventral (A3) views. B. Ventral valve, PKUM02−0506, in posterior (B1), anterior (B2), and ventral (B3) views. C. Dorsal valve, PKUM02−0507, in exterior (C1), lateral (C2), and posterior (C3) views. D. Dorsal valve, PKUM02−0508, viewed internally. E. Dorsal valve, PKUM02−0509, in exterior (E1) and posterior (E2) views. F. SEM micrograph of the dorsal valve, PKUM02−0510, interior showing cardinalia and accessory sockets (arrowed). G. SEM micrograph of the incomplete ventral valve, PKUM02−0511, viewed from the interior (antero−ventral view) showing partially preserved interarea and accessory denticles (arrowed). All from sample MH1. Scale bars 1 mm.