Langella sp.

Sun, Yuanlin & Baliński, Andrzej, 2008, Silicified Mississippian brachiopods from Muhua, southern China: Lingulids, craniids, strophomenids, productids, orthotetids, and orthids, Acta Palaeontologica Polonica 53 (3), pp. 485-524 : 491

Langella sp.

Fig. 5A, B.

1999 Lingula sp. ; Baliński 1999: 441, fig. 3B.

Material.—Twenty two small fragments of both valves, nonsilicified.

Description.—Ventral valve is elliptical in outline with triangular posterior region. Propareas are quite prominent, triangular, elevated; flexure lines present. Pedicle groove narrow, deep and well−defined. Interior characters weakly impressed; very shallow, long, and narrow groove, slightly widening anteriorly, can be revealed. Dorsal valve is elongate elliptical with gently curved posterior margin. Dorsal pseudointerarea is raised, undivided, developed as rounded, arched thickened margin. Interior characters not visible except very weak median ridge which bifurcates at the anterior end. Ornamentation in form of dense concentric growth lines.

Remarks.—The available material is fragmented and some general morphological characters can be only outlined here. General shape of both valves, character of the ventral pseudointerarea as well as some internal markings suggest that the specimens may represent either Barroisella Hall and Clarke, 1892 or Langella Mendes, 1961 . Dorsal interior of the former genus, however, shows a short ridge intercalated at midvalve in the bifurcation of long median ridge which runs from the posterior region of the valve. In Langella the short ridge is not developed as is in the case of the Chinese material. These features indicate that the specimens described here should be assigned to the latter genus.

Stratigraphic and geographic range.—The species is very rare in the Muhua Formation. It was found in samples MH 1, MH 2, M2−8, Mu−42, D2, and D4.