Warthia cf. welleri Yochelson, 1960

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 : 7

Warthia cf. welleri Yochelson, 1960

( Fig. 5 A–D)

cf. Warthia welleri Yochelson, 1960: 255–256 , pl. 48, figs 20–26.

Material. One specimen: ESKU-19- LP 24.

Dimensions (mm): ESKU-19- LP 24: height = 6.5; width = 6.5; thickness = 6.6.

Description. Involute, globose and inflated shell; minutely phaneromphalous; dorsum moderately arched; inductura thick, smooth; whorls smooth with a distinct slit, approximately 20 percent of body-whorl circumference; lips thin; lateral lips gently curved joining anterior lips smoothly; anterior lips evenly straight and slightly curved back forming a slit; aperture gently expanded, kidney-shaped in transverse section with U-shaped indentation.

Remarks. This specimen has a smooth involute shell with a slit representing the genus Warthia . This specimen is the most similar to Warthia welleri Yochelson, 1960 from the Permian of the Southwestern USA in shape and having a short slit, but the aperture of W. welleri is more arcuate than in the present material. The present specimen has a wing-like turnout of lateral lips (see Mazaev 2015) covering large parts of the umbilicus, which differs from W. welleri with gently sickle-shaped lateral lips.

Figures

FIGURE 5. A–D, Warthia cf. welleri Yochelson, 1960, ESKU-19-LP 24. E–G, Warthia sp. 1, ESKU-19-LP 20. H–J, Warthia? sp. 2, ESKU-19-LP 57. All scale bars represent 2 mm.