Cancilla volvaria
Creators: name: Sacchetti, Claudia
name: Landau, Bernard
name: Ávila, Sérgio P.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Neogastropoda
Mitridae
Cancilla
Cancilla volvaria

description: Cancilla volvaria (Bronn, 1862)
Plate 5 I 1 -I 2, J
* Mitra volvaria Bronn in Reiss 1862: 25, pl. 1, fig. 4.
Mitra volvaria Bronn — Mayer 1864: 82, pl. 7, fig. 62.
Type material. Single specimen height 15.5 mm, width 5.5 mm, Pinheiros, Santa Maria Island, Azores; whereabouts unknown (Beu 2017:165).
Santa Maria material examined. Maximum height 10.9 mm, width 4.8 mm. DBUA-F 937-2 (1), DBUA-F 470-1 (1), DBUA-F 1283 -E (1), Ponta do Castelo; DBUA-F 1291-2 (1), Ponta dos Frades; one specimen from LNEG collection (unnumbered), Ponta do Norte lighthouse, Santa Maria Island, Azores, Touril Complex, Lower Pliocene.
Original description. “ Eine ausgezeichnet Walzen-Spindel-f̂rmige ungerippte Art von 8'''-9''' Länge mit 5-6 am Gewinde kaum von einander abgesetzten Umgängen und 3-4 Spindel-Falten; die M̧ndung genau halb so lang als die ganze Schaale, deren Breite kaum ⅓ von der Länge beträgt. Die Schaale auf dem ganzen Gewinde spiral streifig; der letzte Umgang in der Mitte glatt, hinten mit 9-10, vorn wieder mit 2-3 Streifen versehen, welche alle deutlich ausgeprägt und etwas entfernt von einander sind. Die äussre Lippe scharf und einfach. Auf der inneren Seite ist vor den Spindel-Falten ein kurzes Nabel-Fältchen. Die M̧ndung fast durchaus gleichbreit. Diese Art ist bei ihrer geringen Gr̂sse vor andern sehr ausgezeichnet durch ihre Form, ihre lange M̧ndung und Art der Streifung [A fine spindle-shaped, unribbed species of 8'''- 9''' (lines?) in length with a spire of 5-6 whorls hardly separated from each other and 3-4 columellar folds; the aperture is exactly half the height of the entire shell, the width is barely ¼ of the length. The spire whorls bear spiral cords; the last whorl bears 9-10 cords in the upper half, smooth mid-whorl, a further 2-3 cords below, which are all clearly delimited and somewhat distant from each other. The outer lip sharp and simple. On the ventral view there is a small umbilical chink in front of the columellar folds. The aperture is almost the same throughout. This species is very distinguished, due to its small size and its shape with a long aperture and the type of cords.]” (Bronn in Reiss 1862: 25).
Latin description. “ Testa cylindraceo-fusiformi; anfractibus 6, plano-convexis, sutus vix separatis; spira brevi, acuta, transversim striata; ultimo anfractu maximo, ¾ testae efformante, superne et ad basim transversim striato; apertura elongata, dimidiam teste longitudinem vix superante, angusta; labro tenui, perpaulum arcuato; columella quadriplicata.” (Mayer, 1864: 82).
Revised description. Shell small to medium sized, relatively solid, fusiform. Earliest spire whorls missing. Three slightly scalate whorls preserved, bearing four prominent spiral cords. Suture narrowly impressed, linear. Last whorl broadly rounded, weakly constricted at base, bearing flattened spiral cords, subobsolete mid-whorl. Aperture narrow, outer lip simple, anus sinus not developed, siphonal canal relatively short, notched at tip. Columella bearing four oblique folds shortening abapically.
Discussion. We have placed this species in the genus Cancilla Swainson, 1840 based on the presence of relatively strong spiral sculpture. Cancilla species are also characterised by weak cancellate sculpture on the earliest spire whorls (Harzhauser & Landau, 2021: 7), but these are missing in the Santa Maria shell.
The specimen here illustrated (Figs. 5 I 1 -I 2) does not fit exactly with the figure of the holotype (Fig. 5 J), which is slenderer and bullet-shaped. They do concur in the strong spiral sculpture and the presence of four strong folds on the columella. None of the fragments at hand agree with the holotype. Further material would be necessary to assess the number of mitrids present in the Santa Maria assemblages. Nevertheless, its presence is important as it is a marker of warm-water conditions.
Distribution. Lower Pliocene: Atlantic, Santa Maria Island, Azores (Bronn in Reiss 1862; Mayer 1864).
description: Published as part of Sacchetti, Claudia, Landau, Bernard & Ávila, Sérgio P., 2023, The Lower Pliocene marine gastropods of Santa Maria Island, Azores: Taxonomy and palaeobiogeographic implications, pp. 1-150 in Zootaxa 5295 (1) on pages 78-79, DOI: 10.11646/zootaxa.5295.1.1, http://zenodo.org/record/7965273