Thaumastus (Thaumastus) melanocheilus (Nyst, 1845)

Breure, Abraham S. H. & Avila, Valentin Mogollon, 2016, Synopsis of Central Andean Orthalicoid land snails (Gastropoda, Stylommatophora), excluding Bulimulidae, ZooKeys 588, pp. 1-199 : 31-32

Taxon classification Animalia Stylommatophora Megaspiridae

Thaumastus (Thaumastus) melanocheilus (Nyst, 1845) Figs 21 C–D, 34

Bulimus melanocheilus Nyst 1845: 149, pl. 2 fig. 3; Breure 2011: 34, figs 4 A–B, 4i.

Thaumastus melanocheilus ; Richardson 1995: 379 (references, synonymy).

Thaumastus (Thaumastus) melanocheilus ; Ramírez et al. 2003: 282.

Type locality.

“l’Amérique meriodionale, au Pampas".

Type material.

RBINS/MT2361, lectotype ( Breure 2011: 34).

Diagnosis.

Shell relatively large, brownish with a somewhat lighter girdle at the periphery, sculptured with incrassate growth striae and an indistinct spiral striation, suture plicated below, descending in front, aperture elongate-ovate, peristome thickened, hardly expanded below.

Dimensions.

Shell height 78.5, diameter 36.6 mm.

Distribution.

Peru, Dept. Huánuco, Pampayacu ( Breure 2011).

Ecoregion.

Peruvian Yungas [NT0153], Southwest Amazon moist forests [NT0166].

Remarks.

We have found specimens that are intermediate between Thaumastus (Thaumastus) melanocheilus and Thaumastus (Thaumastus) sangoae (Tschudi in Troschel, 1852) on one hand, and between Thaumastus (Thaumastus) melanocheilus and Thaumastus (Thaumastus) robertsi Pilsbry, 1932 on the other hand. The variation and distribution records of these three taxa need more study; they might prove synonyms but molecular studies could help to clarify the systematic position of these species.