Published August 21, 2020 | Version v1
Taxonomic treatment Open

Amalda contusa

  • 1. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninski Prospect 33, 119071 Moscow.
  • 2. Institut de Systématique, Évolution, Biodiversité, ISYEB, UMR 7205 (CNRS, EPHE, MNHN, UPMC), Muséum national d'histoire naturelle, Sorbonne Universités, 43 Rue Cuvier, 75231 Paris Cedex 05, France.

Description

Amalda contusa (Reeve, 1864)

Figs 19 C–D, 20C–D

Ancillaria contusa Reeve, 1864: pl. 9, species no. 31.

Amalda contusa – Gratecap 2012: 19, 27, figs 1–2 (holotype illustrated), 3–5.

Amalda cf. contusa – Gratecap 2012: figs 9–10.

Type Material

Holotype

Holotype by monotypy; locality unknown; NHMUK 197836.

Material examined

Three sequenced specimens (Table 1).

Description

MEASUREMENTS. Shell small (SL up to 25 mm).

SHELL. Broadly ovate, with narrow base and low conical spire. Primary spire callus very thick, smooth and glossy, covering all whorls, except tip of protoconch, rendering measurements impossible. Secondary callus rather thick, with distinct anterior border, smooth and glossy, fusing without visible border with parietal callus, and reaching shell apex. Plication plate smooth, separated from anterior band by broad and deep groove, columella smooth. Olivoid groove shallow but distinct, labral denticle short, obtuse. Anterior band smooth, upper and lower anterior bands weakly convex. Primary callus milky-caramel with irregularly positioned sinuous, brownish axial lines, abapically bordered by interrupted narrow spiral, brown and lighter narrow lines. Secondary callus dark brown, turning very light above aperture. Body whorl cloak background caramel with irregularly spaced, orthocline, brown axial bands of uneven width and lighter spiral colour lines, olivoid band much lighter than cloak, of same tint, anterior band very dark brown, light brown near columella, very light brownish abapically.

RADULA (n =1, sequenced, Fig. 20 C–D). With rather short, hook-shaped lateral teeth. Central tooth broad, with broad lateral flaps, and three major cusps, median more than twice shorter and narrower than lateral ones. Lateral cusps serrated at their base as well as lateral flaps. 1–4 additional, smaller, irregularly shaped cusps between median and lateral major cusps.

Remarks

Our sequenced specimens correspond to what was treated and illustrated by Gratecap (2012: figs 9–10) as A. cf. contusa. This author also provided a lengthy discussion of the complex taxonomic history of A. contusa and concluded that there may be two similar but separate species, one in Natal, and the other in Mozambique and Natal. At present, the lack of comparative material does not allow us to clarify the situation and we provisionally consider our specimens to be the true A. contusa.

Distribution

KwaZulu Natal and Mozambique, in 15– 20 m.

Notes

Published as part of Kantor, Yuri I., Castelin, Magalie, Fedosov, Alexander & Bouchet, Philippe, 2020, The Indo-Pacific Amalda (Neogastropoda, Olivoidea, Ancillariidae) revisited with molecular data, with special emphasis on New Caledonia, pp. 1-59 in European Journal of Taxonomy 706 on pages 51-52, DOI: 10.5852/ejt.2020.706, http://zenodo.org/record/4010954

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Linked records

Additional details

Biodiversity

Collection code
NHMUK
Material sample ID
NHMUK 197836
Scientific name authorship
Reeve
Kingdom
Animalia
Phylum
Mollusca
Order
Neogastropoda
Family
Olividae
Genus
Amalda
Species
contusa
Taxon rank
species
Type status
holotype
Taxonomic concept label
Amalda contusa (Reeve, 1864) sec. Kantor, Castelin, Fedosov & Bouchet, 2020

References

  • Reeve L. A. 1864. Monograph of the Genus Ancillaria. In: Conchologia Iconica, 15. London, Reeve. Available from https: // www. biodiversitylibrary. org / page / 10972403 [accessed 29 Jul. 2020].
  • Gratecap D. 2012. Le genre Amalda en Afrique australe. Xenophora 140: 19 - 29.