Dadagulella cresswelli Rowson & Tattersfield 2013, sp. nov.

Dadagulella cresswelli sp. nov.

urn:lsid:zoobank.org:act: B3362D6F- 2118 -4D1D-8B25-098E25B0C3B2

Figs 29, 57, 84; Table 1

Etymology

After Pete Cresswell, who collected the specimen.

Type material examined

TANZANIA: holotype NMW.Z.2012.042.00001: 1 ad., Ngorongoro Crater, Arusha Region, crater rim on southeastern side, heavy rainforest leaf litter, leg. P.L. Cresswell, 2 Jun.1996.

Other material examined

None.

Description

SHELL (Figs 29, 57). Medium-sized (3.70 mm high x 1.80 mm wide), of 7.0 whorls. Ovate-acuminate, spire coeloconoid (spire angle 52°). Apex sharply pointed. Embryonic whorls smoothly granulate. Later whorls with relatively fine ribs (13 per mm on penultimate whorl). Sutures shallow. Umbilicus narrowly open. Peristome complete. Outer palatal surface of aperture with a very deep, long, furrow-like depression corresponding to the palatal tooth. Dentition 5-fold, consisting of: one V-shaped parietal tooth; one bifid slab-like palatal tooth, forming a clear parieto-palatal sinus, with the upper cusp projecting into the sinus; a deep-set columellar baffle and two shallower columellar denticles. Shells and anatomy of juveniles unknown.

Range and habitat

Forest at the type locality in northern Tanzania. The vegetation is presumably of a montane type, since the crater floor is above 1700 m while the rim rises to over 2400 m or higher.

Remarks

This species is distinctive in its deep, long furrow on the outer palatal surface in combination with the coeloconoid spire and dentition. D. minerata sp. nov. shares these features, but differs in having weaker ribs and less complex dentition. It is the only Dadagulella gen. nov. species thus far collected in the volcanic (as opposed to block-faulted) highlands of Tanzania or Kenya.