Geotrochus kitteli Vermeulen, Liew & Schilthuizen

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 : 108-109

Taxon classification Animalia Stylommatophora Trochomorphidae

Geotrochus kitteli Vermeulen, Liew & Schilthuizen sp. n. Figure 89

Holotype. Malaysia, Sabah, West Coast Province , Kinabalu N.P. , Headquarters area , Silau Silau (leg. K. Kittel, RMNH.5003930 ).

Examined material from Sabah.

West Coast Province, Kinabalu N.P., Sayap-Nunuhon trail at 1776 m (leg. T.S. Liew, Dominik, J. Lapidin & Jasilin, BOR/MOL 4109).

Description.

Shell rather small, rather thin, about opaque, yellowish brown, whorls slightly darker brown towards the periphery, moderately low-conical with approx. flat sides; apex not protruding. Surface dull or slightly shiny above the periphery, shiny below. Whorls: Apical whorls moderately convex, outer slightly convex, slightly shouldered; suture somewhat impressed, coinciding with the periphery; last whorl acutely angular, slightly compressed at the periphery, rounded below the periphery. Protoconch c. 2 1/8 whorls, smooth (see remark, below). Teleoconch. Radial sculpture: above the periphery rather distinct growth lines, raised at irregular intervals and wrinkling the shell surface, most conspicuously so below the suture, and giving the shell surface a somewhat rough appearance; below the periphery indistinct growth lines only. Spiral sculpture: last whorl with a sharp, somewhat pinched peripheral keel; start of fifth whorl with c. 15 thin, moderately spaced spiral threads: 1-2 slightly more distinct close to the periphery, as well as 13-14 inconspicuous above these; no spiral sculpture below the periphery. Umbilicus closed. Peristome thickened and reflexed. Dimensions: Height c. 5.5 mm; width c. 10 mm; h/w c. 0.55; diameters of the first 4 whorls c. 1.2 mm, c. 2.2 mm, c. 3.3 mm, c. 4.8 mm respectively; number of whorls c. 6 3/8, height aperture c. 3.5 mm; width aperture c. 5 mm.

Habitat in Sabah and distribution.

Mixed montane forest, 1500-1800 m alt. Sabah: Mount Kinabalu only. Endemic to Sabah.

Cross diagnosis.

In size and general shape most similar to Geotrochus whiteheadi , it differs by the higher ratio h/w, and by the more distinct growth lines above the periphery, which give the shell surface a rough appearance. It differs from Trochomorpha rhysa by its somewhat pinched peripheral keel and the not-nodular spiral sculpture above the periphery.

Remarks.

The single shell available is somewhat worn in the apical region. Traces of what may be radial riblets are present in the suture of the protoconch, close to the transition to the teleoconch.

Etymology.

Named after Mr. Klaus Kittel, Germany, who collected the type specimen.