Middle Permian (Roadian) gastropods from the Khao Khad Formation, Central Thailand: Implications for palaeogeography of the Indochina Terrane
Author
Ketwetsuriya, Chatchalerm
Author
Karapunar, Baran
Author
Charoentitirat, Thasinee
Author
Nützel, Al- Exander
text
Zootaxa
2020
2020-04-17
4766
1
1
47
journal article
10.11646/zootaxa.4766.1.1
ed4d1bf6-284a-4898-952a-58943d5a3026
1175-5334
3763907
urn:lsid:zoobank.org:pub:B1B5DA41-5035-4783-8D47-28857B6305AE
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.