Cryptonella sp. 1

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 : 836

Cryptonella sp. 1

Fig. 34A, B, D–F, J .

Material.—Four incomplete shells and 2 fragmentarily preserved dorsal valves from samples MH1, MH2, and GT.

Remarks.—There is no doubt that several representatives of terebratulidins are present in the Muhua fauna. Unfortunately the material is very fragmentary and it is not possible to determine how many and which taxa are actually present. Some of the specimens show a densely punctate, elongate shell, nearly straight and long ventral umbo, thin dental plates, and slightly concave, undivided and unsupported hinge plate with an apical perforation ( Fig. 34A, B, D–F, J ). The two almost complete shells attain 9.3 and 4.4 mm in length and 6.2 and 2.6 mm in width, respectively ( Fig. 34 A, B ). These internal and external characteristics suggest that the specimens should be placed within genus Cryptonella . Although the genus is known mainly from the Devonian, at least two species were recorded from the Carboniferous, i.e., C. minranensis Brunton, 1984 (Viséan, lower Carboniferous, Co. Fermanagh, Ireland; Brunton 1984) and C. simplex Pérez−Huerta, 2004 (late Moscovian, Pennsylvanian, Nevada, USA; Pérez−Huerta 2004).

Figures

Fig. 34. Terebratulide brachiopods from the Tornaisian Muhua Formation, southern China. A, B, D–F, J. Cryptonella sp. 1. A. Slightly damaged shell, PKUM02−0581, in dorsal (A1) and lateral (A2) views. B. Incomplete juvenile shell, PKUM02−0582, in dorsal (B1), ventral (B2), and lateral (B3) views. D. Incomplete ventral valve, PKUM02−0583, in interior (D1) and exterior (D2) views. E. Interior of incomplete dorsal valve, PKUM02−0584, showing well preserved cardinal plate and crural bases. F. Incomplete dorsal valve, PKUM02−0585, viewed from the interior (F1) and enlargement of the posterior region showing cardinalia (F2). J. Incomplete juvenile shell, PKUM02−0586, with well visible endopunctae. C, G, I. Cryptonella sp. 2. C. Interior of incomplete dorsal valve, PKUM02−0587, in general view (C1) and enlargement of slightly tilted posterior region showing cardinal plate, sockets and elongate muscle scars. G. Incomplete ventral valve, PKUM02−0588, viewed from the interior showing conjunct deltidial plates, teeth, and pedicle foramen. I. Interior of incomplete dorsal valve, PKUM02−0589, showing unsupported cardinal plate. H, K. Cryptonelloid gen. et sp. indet. H. Interior of incomplete dorsal valve, PKUM02−0590, showing divided hinge plates (damaged cardinal plate?). K. Incomplete dorsal valve, PKUM02−0591, in exterior (K1) and interior (K2) views showing probably damaged cardinal plate. E, F, J, SEM micrographs. Samples MH1 (A–E, G–I, K), MH2 (F), and GT (J). Scale bars 1 mm.