Oospira luneainopsis Man & Panha, 2023

Man, Nem Sian, Lwin, Ngwe, Sutcharit, Chirasak & Panha, Somsak, 2023, Further notes on the taxonomy of the land snail family Clausiliidae Gray, 1855 (Stylommatophora, Helicina) from Myanmar with description of two new species, ZooKeys 1160, pp. 1-59 : 1

12 Oospira luneainopsis Man & Panha sp. nov.

Figs 16A-C , 18P

Type material.

Holotype CUMZ 13062 (Fig. 16A ). Measurements: shell height 20 mm, shell width 5.8 mm, and 7 whorls. Paratypes CUMZ 13063 (8 shells; Fig. 16B, C ), NHMUK 20220504 (2 shells).

Type locality.

Limestone outcrop at Zwegabin Mountain, Hpa-an Township, Hpa-an District, Kayin State, Myanmar (16°48'44.5"N, 97°40'25.5"E).

Etymology.

The specific name luneainopsis is a compound of ‘lun-eain’, which in the Myanmar language refers to a bobbin used for traditional Myanmar weaving, and the Greek suffix - opsis meaning 'having the appearance of or like’. It refers to the bobbin shape of the shell of this species.

Diagnosis.

Shell ovate-fusiform, decollated with smooth surface and dense striations near suture. Last whorl neck subquadrate; aperture nearly roundish; peristome detached. Inferior lamella straight ascending and reaching at peristome; palatal plicae four, distinct, equally, and parallelly arranged, and superior lamella developed.

Description.

Shell ovate-fusiform, decollated, opaque, pinkish brown; spire blunt. Shell surface smooth to with fine growth lines on last whorl, denser near suture and last whorl neck subquadrate; suture impressed and distinct. Whorls 7-8, convex, regularly growing, and bluntly attenuated to apex. Aperture nearly round; peristome detached, thickened, expanded and little reflexed. Superior lamella developed, continuous with spiralis, and slightly low at transition to spiralis. Inferior lamella steeply ascending, distant from superior lamella and ending at peristome. Subcolumellaris emerged and invisible in oblique view. Principalis running along lateral-dorsal side and anterior end visible through oblique apertural view. Palatal plicae lateral, four: first and fourth plicae strong and longest; remaining plicae parallel and equal length; sometimes tiny lowest plica present. Clausilium plate lateral side, narrow and slightly pointed at tip.

Distribution.

Oospira luneainopsis sp. nov. is only known from the type locality.

Remarks.

No ethanol preserved specimens were available for anatomical study. This species can be distinguished from O. gouldiana , O. magna , and O. zediopsis sp. nov. by its small size, decollated, fewer whorls, roundish aperture, more spiral inferior lamella, and equal palatal plicae. This new species is clearly distinct from O. decollata by its spiral inferior lamella visible from aperture, smoother shell, pink color, and more bulging whorls.

Compared to the Vietnamese dextral species, O. duci Maassen & Gittenberger, 2007 exhibits thinner and oblique aperture, sinus higher, obviously emerged subcolumellaris, very fine striations and more ventrally unequal palatal plicae than this species.

Figures

Figure 16. Shell and clausilial apparatus of A-C Oospira luneainopsis sp. nov. A shell of holotype CUMZ 13062 from Zwekabin Mountain, Kayin State B, C paratypes CUMZ 13063 from the type locality B clausilial apparatus C shell and D-F Oospira zediopsis sp. nov. D clausilial apparatus of paratype CUMZ 13065 from the type locality E shell of holotype CUMZ 13064 from Weibyan Cave, Kayin State and F shell of paratype CUMZ 13065 from the type locality.

Figure 18. Synoptic view of the clausiliid species recorded from Myanmar A Indonenia admirabilis, holotype NHMUK 20200185 B Oospira andersoniana, specimen CUMZ 13054 C Oospira arakana, lectotype NHMUK 1888.12.4.1037 D Cylindrophaedusa bacillum, specimen NHMUK 1906.2.2.345 E Oospira bulbus, possible syntype NHMUK 1903.7.1.1278 F Phaedusa burmanica, holotype NHMUK 1888.12.4.1058 G Oospira decollata, paratype ZISP H Indonenia excellens, specimen NHMUK 20200189 I Oospira fusiformis, holotype NHMUK 1906.2.2.380 J Oospira gouldiana, lectotype NHMUK 196548 K Oospira gracilior, lectotype NHMUK 1907.12.30.243 L Oospira insignis, lectotype USNM 117120 M Phaedusa kazueae, holotype NHMUK 20200187 N Phaedusa lemani (after Gude, 1914: fig. 107) O Oospira limborgi, holotype NHMUK 1903.7.1.1266, and P Oospira luneainopsis sp. nov., holotype CUMZ 13062.