Tritia vetulum (Mayer, 1862)

Sacchetti, Claudia, Landau, Bernard & Ávila, Sérgio P., 2023, The Lower Pliocene marine gastropods of Santa Maria Island, Azores: Taxonomy and palaeobiogeographic implications, Zootaxa 5295 (1), pp. 1-150 : 74

Tritia vetulum (Mayer, 1862)

Plate 5 D

* Buccinum (Nassa) vetulum Mayer , in Bronn in Reiss 1862: 26, fig. 5.

Buccinum vetulum Mayer — Mayer 1864: 76, pl. 7, fig. 57.

Type material. Single specimen height 12.0 mm, width 6.0 mm, Pinheiros, Santa Maria Island , Azores; whereabouts unknown ( Beu 2017:165) .

Original description. “ In Form und Gr̂sse mit Buccinum corniculum Olivi ( B.fasciolatum Lk. )̧bereinstimmend, aber etwas schlanker. Die innre Lippe, wenn auch nicht sehr dick, doch fast ̧ber die ganze Bauch-Seite des letzten Umganges heŗber-geschlagen. Form konisch, halb so dick als lang, und der letzte Umgang von halber Länge der Schaale; die 6 Umgänge des Gewindes wenig geŵlbt, an der Naht fein Treppen-artig abgesetzt; die äussre Lippe aussen schwach gerandet (das Innere nicht sichtbar): die Oberfläche schwach spiral-streifig, am Grunde des letzten Umganges mit einigen schärfern Streifen [Consistent in shape and size with Buccinum corniculum Olivi ( B. fasciolatum Lk. ), but slightly slenderer. The inner lip callus, although not greatly thickened, but almost over the entire venter. Shape conical, half as wide as long, and the last whorl of half the length of the shell; the 6 whorls of the spire slightly curved, slightly scalate; the outer lip weakly varicose (the inside not visible): the surface weakly spirally sculpted with some sharper cords at the base.]” (Bronn in Reiss 1862: 26).

Latin description. “ Testa obovato-conica, crassiuscula, solida, transverssim tenuissime sulcata ; spira acuta; anfractibus 7, convexo-planis, subcontiguis, sutura subcanaliculata separatis, ultimo dimidiam testae longitudinis paulo superante, basi attenuato, multisulcato, sulcis profundis, dorsum versus sensim humilioribus, apertura angusta, ovata, in canalem obliquum, brevem, angustum, exeunte, labro incrassato, columella arcuata, callo mediocriter repando.” ( Mayer, 1864: 76).

Discussion. Buccinum vetulum Mayer , in Bronn in Reiss, 1862 clearly belongs within the Nassarius semistriatus species group of Landau et al. (2009: 12). The genus used for all these species now is Tritia Risso, 1826 . Mayer’s in Bronn in Reiss (1862: 26) original comment that the species was similar to T. semistriata ( Brocchi, 1814) and comparison to his new taxon T. atlantica (Mayer, in Bronn in Reiss, 1862) is correct. His later comment in Mayer (1864: 76) were he liked it to certain columbellids is odd, as the figure clearly represents a Tritia species. According to Mayer, in Bronn in Reiss (1862), T. vetulum differ from T. atlantica in being smaller and slenderer. From the illustration, it seems that the spiral sculpture may be a little stronger than that seen in the figure of T. atlantica . These differences are not totally convincing, and it might be that they represent extremes of a single species. However, in the absence of further material we maintain the two species separate.

Distribution. Lower Pliocene: Atlantic, Santa Maria Island, Azores (Mayer, in Bronn in Reiss 1862; Mayer 1864).

Figures

PLATE 5. A1-A2. Tritia atlantica (Mayer, 1862), DBUA-F 1295-2, height 13.0 mm, width 6.5 mm, Malbusca (east cave). B1-B2 C1-C2. Tritia serraticosta (Ĥrnes, 1852), DBUA-F 1292-A, height 6.2 mm, width 4.1 mm (B); height 8.1 mm, width 4.2 mm (C), Macela viewpoint. D. Tritia vetulum (Mayer, 1862), height 12.0 mm, width 6.0 mm, Pinheiros (figure taken from Bronn in Reiss, 1862, pl. 1, fig. 5). E1-E2. Aplus sp., height 7.5 mm, width 4.0 mm, Ponta do Castelo, LNEG collection (unnumbered). F1- F2. Orania cf. bellardiana (Foresti, 1884), DBUA-F 828-2, height 17.0 mm, width 12.0 mm, Ponta dos Frades. G1-G2. Favartia suboblonga (d’Orbigny, 1852), DBUA-F 946-3, height 19.0 mm, width 10.0 mm, Ponta dos Cedros. H1-H2. Bellardithala obsoleta (Brocchi, 1814), DBUA-F 542-4, height 5.9 mm, width 2.0 mm, Ponta dos Frades. I1-I2 J. Cancilla volvaria (Bronn, 1862), DBUA-F 937-2, height 10.9 mm, width 4.8 mm (I), Ponta do Castelo; height 15.5 mm, width 5.5 mm (J), Pinheiros (figure taken from Bronn in Reiss, 1862, pl. 1, fig. 4). K. Mitra (s.l.) peregrinula Mayer, 1864 species inquirenda, height 5.5 mm, width 2.5 mm, Feteirinhas (= Ponta das Salinas) (figure taken from Mayer, 1864, pl. 7, fig. 61). L1-L2. Mitra (s.l.) sp., DBUA-F 1295-3, height 12.9 mm, width 7.0 mm, Malbusca (east cave). M. Africonus trochilus (Mayer, 1864), length 16.0 mm, width 9.0 mm (incomplete spire fragment), Pinheiros, (figure taken from Mayer, 1864, pl. 7, fig. 60). N1-N2. Lautoconus cf. anomalomamillus (Sacco, 1893), DBUA-F 924-1, height 22.0 mm, width 11.0 mm, Malbusca. O. Plagioconus sp., height 35.5 mm, width 16.0 mm, unknown locality, LNEG collection (unnumbered). P1-P2 Q. Stephanoconus candidatus (Mayer, 1862), DBUA-F 913, diameter 19.0 mm (apical fragment of juvenile), Ponta dos Frades (P); diameter 40.0 mm, height 22.0 mm (incomplete spire fragment), Pinheiros (figure taken from Bronn in Reiss, pl. 1, fig. 1).