Strobeus, de Koninck, 1881

Ketwetsuriya, Chatchalerm, Karapunar, Baran, Charoentitirat, Thasinee & Nützel, Al- Exander, 2020, Middle Permian (Roadian) gastropods from the Khao Khad Formation, Central Thailand: Implications for palaeogeography of the Indochina Terrane, Zootaxa 4766 (1), pp. 1-47 : 33

Strobeus ? sp. 1

( Fig. 22 A–C)

Material. Two specimens: ESKU-19- LP 49, 90.

Dimensions (mm): ESKU-19- LP 49: height = c. 10.4; width = c. 10.9; apical angle = 90 º. ESKU-19- LP 90: height = 6.5; width = 5.9; apical angle = 82 º.

Description. Subglobose, broad, low-spired shell with elevated, acute spire; approximately four whorls; whorl embracing above periphery; whorls smooth; spire-whorls very slightly convex; periphery convex. Rounded; bodywhorl very inflated, strongly convex, rounded; suture shallow; base evenly rounded, inductura seemingly thick; aperture acute adapically, broken abapically.

Remarks. The incomplete specimens resemble Strobeus welleri Knight, 1931 a (p. 219, pl. 23, fig. 1) from the Desmoinesian (Pennsylvanian) Labette Shale of Missouri, USA. This species has also been reported from the Permian of Cambodia ( Delpey, 1941; p. 61, fig. 54), the Middle Pennsylvanian of New Mexico ( Kues & Batten, 2001; p. 85, fig. 16.30) and the Permian of Mexico (Sour-Tovar et al. 2005). The present specimens also resemble several other Late species representing Strobeus but it more low-spired than most of them. However, the broken aperture prevents an identification; presence or absence of columellar folds are important characters that cannot be seen in the present material.

Figures

FIGURE 22. A–C, Strobeus? sp. 1, A–B, ESKU-19-LP 49. C, ESKU-19-LP 90. D–E, Strobeus? sp. 2, D, ESKU-19-LP 217. E, ESKU-19-LP 220. F, Girtyspira? sp., ESKU-19-LP 222. G, Heterosubulites longusapertura sp. nov. ESKU-19-LP 215, holotype. Scale bars represent: 2 mm (A–C); 200 μm (D–G).