Naticopsis, McCoy, 1844

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 : 27

Naticopsis sp. 1

( Fig. 20 A–C)

Material. One specimen: ESKU-19- LP 47.

Dimensions (mm): ESKU-19- LP 47: height = c. 8.3; width = 11.3; apical angle = 115º.

Remarks. The present specimen at hand shows 3 teleoconch whorls that are inflated and rapidly increasing. The shell is low-spired. Whorls are convex and the whorl profile is quite elongated. The surface of whorls is smooth. The suture is impressed and embraces the upper whorl surface. The aperture is broken, but it seems to be ovate with distinctly thickened callus on the parietal area. Judging from a single shell exhibiting the spire and half of the last body-whorl, the whorl profile of the studied specimen is similar to Naticopsis khurensis Waagen, 1880 (p. 100, pl. 9, fig. 10) from the Permian of Pakistan (Salt Range) but the latter differs in the absence of a callus. In contrast to the type specimen, the specimens illustrated and described as N. khurensis by Batten (1979, p. 13, fig. 15) from the Permian of Perak, Malaysia exhibits a callus. Nevertheless, the present specimen differs from the Malaysian specimen in having a more swollen upper whorl surface of the body-whorl. The specimens identified as Neritina khurensis by Delpey (1941, p. 271, fig. 13) from the Permian of Cambodia has a lower spire and its upper whorl surface is less inflated. Batten (1979) discussed that the degree of whorl curvature is highly variable in N. khurensis , so we cannot completely rule out the possibility that the studied specimen is conspecific to Naticopsis khurensis .

Figures

FIGURE 20. A–C, Naticopsis sp. 1, ESKU-19-LP 47. D–F, Naticopsis sp. 2, ESKU-19-LP 46. G–I, Naticopsis? sp. 3, ESKU- 19-LP 32. J, Naticopsis? sp. 4, ESKU-19-LP 52. K–L, Naticopsis cf. heshanensis Pan & Erwin, 2002, ESKU-19-LP 44. Scale bars represent: 2 mm (A–J); 5 mm (K–L).