Geotrochus kinabaluensis (E.A. Smith, 1895)

Vermeulen, Jaap J., Liew, Thor-Seng & Schilthuizen, Menno, 2015, Additions to the knowledge of the land snails of Sabah (Malaysia, Borneo), including 48 new species, ZooKeys 531, pp. 1-139: 102-103

publication ID

http://dx.doi.org/10.3897/zookeys.531.6097

publication LSID

lsid:zoobank.org:pub:C845838E-C912-4BD8-AB4E-07980F91959E

persistent identifier

http://treatment.plazi.org/id/665E4ED1-D614-2AC6-4586-9C2904F505F5

treatment provided by

ZooKeys by Pensoft

scientific name

Geotrochus kinabaluensis (E.A. Smith, 1895)
status

 

Taxon classification Animalia Stylommatophora Trochomorphidae

Geotrochus kinabaluensis (E.A. Smith, 1895)  Figure 84

Trochonanina kinabaluensis  E.A. Smith, 1895: 105. Type from Malaysia, Sabah, Mount Kinabalu.

Trochonanina kinabaluensis E.A. Smith var. pallida  E.A. Smith, 1895: 106. Type from Malaysia, Sabah, Mount Kinabalu.

Examined material from Sabah.

Interior Province. Crocker Range N.P., West of the km 10 marker on the road Tambunan-Ranau, Mahua Waterfall (leg. Suhaili, BOR/MOL 3372). West Coast Province. Kinabalu N.P., Poring Hot Springs, leg. M. Schilthuizen & P. Koomen, BOR/MOL 2933); Sayap-Nunuhon trail at 1152 m (leg. T.S. Liew, Dominik, J. Lapidin & Jasilin, BOR/MOL 4025); Serinsim-Nombuyokon trail at 5.6-6 km (leg. T.S. Liew, BOR/MOL 4026); Kiau-Spurs route at 2800 m (leg. T.S. Liew, J. Lapidin & Safrie, BOR/MOL 4027).

Description.

Shell medium-sized, rather thin, opaque, brown, sometimes a slightly paler brown just below the suture, periphery pale brown to dull white; shell low-conical with approx. flat sides, apex not or hardly protruding. Surface with a silky luster above the periphery, shiny below. Whorls: slightly convex; suture impressed in the inner whorls, not so in the outer, coinciding with the periphery; last whorl acutely angular, moderately compressed at the periphery, slightly convex below the periphery. Protoconch c. 2 1/8 whorls, smooth. Teleoconch. Radial sculpture: above and below the periphery scattered inconspicuous growth lines, locally grading into inconspicuous riblets; next to this a very fine (just visible at 40 times magnification) radial wrinkling of the shell surface is locally present. Spiral sculpture: last whorl with a sharp, slightly pinched peripheral ridge; start of fifth whorl with 15-17 somewhat spaced, low and thin spiral threads, the 2-5 threads close to the periphery slightly more distinct, the others inconspicuous; no spiral sculpture below the periphery. Umbilicus closed. Peristome thickened and reflexed, basal edge most strongly curved towards the columellar side, approx. straight or slightly concave towards the periphery. Dimensions: Height 7.4-10.0 mm; width 17.6-24.5 mm; h/w 0.41-0.42; peripheral keel of the last whorl at 0.40-0.45 of the shell height, measured from the apex; diameters of the first 4 whorls 1.5-1.6 mm, 2.4-2.6 mm, 3.4-4.6 mm, 5.8-6.5 mm respectively; number of whorls 6 1/2-6 3/4, height aperture 4.0-5.5 mm; width aperture 9.0-13.0 mm.

Habitat in Sabah and distribution.

Primary and secondary forest on sandstone and shale bedrock, 600-2800 m alt. Lives on decaying wood. Sabah: Mount Kinabalu, Crocker Range. Endemic to Sabah.

Cross diagnosis.

See under Geotrochus labuanensis  . The limited material seen of Geotrochus kinabaluensis  suggests that the shells are usually higher and wider than those of Geotrochus labuanensis  , and that the aperture is usually larger.

Remarks.

The exact morphology of a very fine radial wrinkling of the supra-peripheral part of the shell needs to be investigated.

Geotrochus kinabaluensis  is a submontane species, contrary to Geotrochus labuanensis  .