Platyspirifer paronai ( Martelli, 1902 )

Ma, Xue-Ping, Sun, Yuan-Lin, Hao, Wei-Cheng & Liao, Wei-Hua, 2002, Rugose corals and brachiopods across the Frasnian- Famennian boundary in central Hunan, South China, Acta Palaeontologica Polonica 47 (2), pp. 373-396 : 393-394

Platyspirifer paronai ( Martelli, 1902)

Fig. 15A–E .

Schizophoria Paronai sp. nov.; Martelli 1902: 365–367, pl. 14: 21–24.

Platyspirifer paronai ( Martelli, 1902) ; Grabau 1931: 355–357, pl. 37: 2–4;

Platyspirifer paronai ( Martelli, 1902) ; Hou et al. 1996a: 161, pl. 1: 4–6, pls. 5–6, text−fig. 4.

Material.—Thirty well preserved complete specimens.

Remarks.—This species is characterized by short hinge, low and flat plications, very narrow interspaces, shallow sinus and internally with a long, thick delthyrial plate in ventral valve and a well developed large comb−like cardinal process ( Hou et al. 1996a: 160, text−fig. 4). All previous authors have recorded the delthyrium as open without a pseudodeltidium. We have found that this structure is present in some specimens and hence it would have been present in all specimens when they were alive.

Wang et al. (1964: 470) pointed out that a young specimen of P. paronai (Cat. No. 784) is very similar to P. subparonai Grabau, 1931 in shell indices, outline, and bifurcation pattern of plications. Whereas Hou et al. (1996a: 161) suggested that “ Platyspirifer subparonai Grabau, 1931 may be rejected from genus Platyspirifer because its cardinal angles truncate and project sharply beyond the shell margins”. Based on our observations we concur with the opinion of Hou et al. (1996a).

Occurrence.— Shaanxi Province ( Martelli 1902), but not proved by recent geological investigation; in the Jiangjiaqiao section (Qidong County), early Famennian .

Figures

Fig. 15. A–E. Platyspirifer paronai (Martelli, 1902), sample C−H.A. Interarea view of PUM 00026 showing the convex pseudodeltidium, × 2.75. B, C. Lateral and ventral views of PUM 00022; × 1.5. D, E. Dorsal and anterior views of PUM 00038; × 1.2. F–J. Cyrtiopsis? cyrtiopsiformis (Yang, 1977), sample C−H, anterior, ventral, dorsal, lateral, and posterior views of PUM 97011; all × 2 except I × 1.5. K–O. Sinospirifer subextensus (Martelli, 1902), sample C−H, anterior, posterior, dorsal, ventral and lateral views of PUM 00023; × 1.3. P, Q. Lamarckispirifer hayasakai (Grabau, 1931), sample C−H, anterior and posterior views of PUM 00028; × 1.3. R. Sinospirifer gortanioides Grabau, 1931; sample C−H, anterior view of PUM 98014, × 1.3.