Fig. 19 in Silicified Mississippian brachiopods from Muhua, southern China: Rhynchonellides, athyridides, spiriferides, spiriferinides, and terebratulides

Fig. 19. Retzioid and nucleospiroid brachiopods from the Tornaisian Muhua Formation, southern China. A. Retzioid Hustedia sp.; nearly complete shell, PKUM02−0468, in dorsal (A1), lateral (A2), and enlarged dorsal (A3) views. B, F–I. Retzioid Acambona sp. B. Umbonal fragment of dorsal valve, PKUM02−0469, in interior (B1) and posterior (B2) views showing complexity of cardinalia. F. Slightly incomplete dorsal valve, PKUM02−0470, in interior (F1) and enlarged interior (F2) views. G, H. Umbonal region of two dorsal valves, PKUM02−0471 (G) and PKUM02−0472 (H), in anterior view with labelled morphology. I. Incomplete ventral valve, PKUM02−0473, in exterior (I1) and interior (I2) views. C–E. Nucleospiroid Nucleospira sp. C. Interior of incomplete dorsal valve, PKUM02−0474. D, E. Two posterior fragments of shell, PKUM02−0475 (D) and PKUM02−0476 (E), in anterior view showing cardinalia; ventral valve at the top. A, D, E, G, and H, SEM micrographs. Samples MH1 (A, C–E) and MH2 (B, F–I).