Peruvispira, Chronic, 1949

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 : 16

Peruvispira sp.

( Fig. 12 )

Material. Two specimens: ESKU-19- LP 10, 68.

Dimensions (mm): ESKU-19- LP 10: height = c. 2.7; width = c. 2.0. ESKU-19- LP 68: height = c. 3.3; width = 3.1.

Description. Shell small, conical, moderately high-spired; suture distinct, situated just below basal edge; whorl face above selenizone slightly convex near suture, concave above selenizone, ornamented with very faint, obliquely elongated, prosocline/prosocyrt subsutural nodes; upper whorl face three times as wide as the lower whorl face; selenizone wide, concave, slightly raised, situated at lower half of whorl face, bordered above and below by pronounced spiral cords; lower cord forms periphery; the whorl face below selenizone concave, smooth; basal edge rounded; base convex, smooth; aperture subovate, outer lip convex angular, basal lip convex, lower half of the columellar lip slightly reflexed; base anomphalous.

Remarks. The whorl profile is very similar to that of Peruvispira turrita Yu, 1980 from the Permian of Guizhou, but it is not clear whether the latter species has subsutural nodes or not. P. allandalensis Fletcher, 1958 and P. trifilata ( Dana, 1847) from the Permian of Australia are other similar species but they differ in having collabral threads and a rather convex upper and lower whorl face.

Figures

FIGURE 12. Peruvispira sp., A–C, ESKU-19-LP 10. D, ESKU-19-LP 68. All scale bars represent 1 mm.