Rhyssochonetes Johnson, 1970

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 : 383

Genus Rhyssochonetes Johnson, 1970 Rhyssochonetes ? sp. 1

Fig. 9A, B .

Material.— Two specimens, one of which is well preserved.

Remarks.—The current specimens are similar to species of Rhyssochonetes in their external morphology, such as the transverse outline, moderately to strongly concavoconvex profile, symmetrically arranged orthomorph oblique spines, distinct radial ornamentation of rounded costae (with intercalated costae from mid−length) crossed by fine, closely−spaced concentric fila, and in lacking accessory septa in the interior of the dorsal valve. They differ from species of Rhyssochonetes in lacking dorsal median septum.

Occurrence.—Central Hunan Province; in the Shetianqiao section (sample S−Y−2), late Frasnian.

Figures

Fig. 9. A, B. Rhyssochonetes? sp. 1, sample S−Y−2, ventral and dorsal views, PUM 00055; × 3. C–E, S. Rhyssochonetes? sp. 2, sample S−H−0. C. Ventral view, PUM 00062, × 3. D. Dorsal view showing the interarea, PUM 00048, × 5. E. Ventral view, note the orthomorph parallel arranged hinge spines (arrowed), PUM 00061b, × 3. S. Enlargement of arrowed area of E, × 11.5. F–H. Leioproductus hunanensis Liu, 1982, sample C−H, lateral, dorsal and ventral views, PUM 00031, × 2. I. Productella sp. 2, sample C1−0, dorsal view showing some spines present on the valve, PUM 00035, × 3. J, K. Productella lachrymosa var. asiatica Tien, 1938; sample C7. J. Ventral view, PUM 00002, × 1.5. K. Dorsal view, PUM 00032, × 2. L, M. Productella sp. 1, sample S−Y−4.L. Ventral view, PUM 00018, × 2. M. Dorsal view, PUM 00015, × 2. N–R. Praewaagenoconcha linglingensis (Wang, 1956), sample C−H. N. Dorsal view, PUM 00030, × 2. O. Dorsal view, PUM 00034, × 2. P, Q. Ventral and lateral views, PUM 00024; × 2. R. Dorsal interior showing the slit−like sockets, PUM 00059, × 3.3. T–V. Sinalosia rugosa gen. et sp. nov., sample S−Y−2. T. Showing the distinct interarea with ventral pseudodeltidium and dorsal chilidium, which is medially divided by cardinal process as to form a narrow V−shaped slit gap, PUM 01001, × 6. U, V. Lateral and internal views of cardinal process, PUM 01002; × 6.