Hunanotoechia gamma ( Tien, 1938 )

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 : 386-387

Hunanotoechia gamma ( Tien, 1938)

Fig. 10J–Q .

Camarotoechia shetienchiaoensis var. (var. nov.); Tien 1938: 39–40, pl. 4: 13–15.

Camarotoechia gamma Tien ; Wang et al. 1964: 359, pl. 60: 5–8.

Material.—Seventy−two well preserved specimens.

Remarks.—Our specimens agree in general morphology with Tien’s species originally described from the Shetianqiao Formation of Xiangxiang County, for example, two to five sinal plications, zero to one parietal plication on each side, four to six sinal plications, and total number of shell plications (20–25: our observation shows that Tien’s type specimens have 20–25 shell plications, not 14–18 as originally reported by Tien 1938: 39). Rare specimens have only two sinal plications ( Fig. 10J ).

Tien (1938) described Camarotoechia shetienchiaoensis and its three varieties:,, and. Wang et al. (1964) recognized only two species: C. shetienchiaoensis (including var.) and C. gamma (including var.). Our observation shows that all those taxa probably should be assigned to the same species. However, we would rather follow the opinion of Wang et al. (1964) in this paper pending more topotype specimens available to study their morphologic variations. This species is assigned to Hunanotoechia on the basis of its small size and similar general shape and ventral posterior. H. tieni , the type species of Hunanotoechia , is different from this species by having more shell plications (40–50 vs. 20–25).

Occurrence.—Shetianqiao section; late Frasnian (Lower to Upper Pa. rhenana zones).

Figures

Fig. 10. A–F. Sinalosia rugosa gen. et sp. nov., sample S−Y−2. A–C. Ventral, dorsal and lateral views of holotype PUM 00017; × 2. D. Ventral view of paratype PUM 00019 showing its chevron ornamentation, × 2. E, F. Ventral and dorsal views of paratype PUM 00021; × 2. G–I. Hypothyridina linglingensis Wang, 1956a; sample S−Y−4, lateral, ventral and posterior views of PUM 00027; × 1.25. J–Q. Hunanotoechia gamma (Tien, 1938), sample S−Y−2. J. Ventral view of PUM 00042 showing the presence of only two sinal plications, × 3. K–O. Lateral, dorsal, posterior, anterior and ventral views of PUM 00051; × 3. P. Dorsal view of PUM 00041 showing a specimen with growth bizarre ventral beak, × 3. Q. Dorsal view of PUM 00054 showing the deltidial plates, × 5. R, S. Hunanotoechia tieni Ma, 1993; sample S−25−2, PUM 00053, enlarged dorsal view (R) showing the deltidial plates and the foramen, × 4 and ventral view (S), × 3.