Genus Amatholedonta gen. nov.

urn:lsid:zoobank.org:act: 18997261-62F4-455F-BE93-F786B3F27553

Type species

Afrodonta bimunita Connolly, 1939 .

Diagnosis

Shell relatively large (max. diameter ±2.0 mm), biconcave with deeply sunken spire; umbilicus moderate to wide; whorls deep and tightly coiled, strongly rounded apically and basally, less so at periphery; last adult whorl not descendant. Protoconch smooth, apical cap noticeably swollen, almost circular; teleoconch with fine, close-set, axial riblets; riblets compound, composed of several periostracal lamellae; intervals between riblets with fine intermediary axial threads; spiral sculpture faint, mostly scarcely evident. Aperture narrowly lunate; parietal dentition absent; palatal region with 1–3 axially aligned rows of denticles set back up to ⅓ whorl behind outer lip.

Etymology

From the Amathole Mountains, and donta: a contraction of Afrodonta . Gender feminine.

Remarks

Amatholedonta gen. nov. is proposed for two deeply biconcave species from neighbouring regions in the Amathole Mountains. The genus is characterised by the deep shell, fine axial teleoconch sculpture, smooth globose protoconch and episodic deposition of palatal denticles. Species of Costulodonta gen. nov. may be similar, but they have less deep whorls, a flat or slightly raised spire, and a costate protoconch.