Thericium hartungi (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 : 29-30

Thericium hartungi (Mayer, 1862)

Plate 1 G 1 -G 2

* Cerithium Hartungi Mayer , in Bronn in Reiss 1862: 30, pl. 1, fig. 11.

Cerithium Hartungi Bronn [sic] in Reiss— Mayer 1864: 65, pl. 6, fig. 44 (47 in text; lapsus).

Type material. Single specimens, height 29.0 mm, width 13.0 mm, Pinheiros, Santa Maria Island , Azores; whereabouts unknown ( Beu 2017: 165) .

Original description. “ Eine nur unvollkommen erhaltene, aber durch ihre k̂rnelige Spiralstreifung ausgezeichnete Art. Es sind nur die 10 ersten Windungen eines einzigen Exemplars vorhanden, die in Ganzen einen regelmässigen, etwas ̧ber 1" langen Kegel vorstellen, der von genau halb so dick als lang ist. Die Umgänge sind eben und durch eine gerundet treppige Aufwulstung nach der Naht hin selbst etwas in der Mitte vertieft. Die ganze Oberfläche des letzten Umganges ist mit kaum sichtbaren Spiralstreifen bedeck, welche auch auf den fŗheren Umgängen bereits verschwunden sind. Vor (oder unter) der vertieften Mitte zeigen sich jedoch ausserdem zuerst 1-2 deutlichere einfache Spiral-Streifen und dann 6 fein Perlschnur-artig gek̂rnte, von welchen nur die erste noch etwas hinter der Naht auf allen Umgängen verfolgt werden kann, während die Naht selbst auf der zweiten verläuft und dadurch ein sehr fein-welliges Ansehen bekommt. Die 2 letzten setzen in die M̧ndung fort. (Der äussre Mund-Rand fehlt; der Kanal an dessen Grunde mag ziemlich längsläufig gewesen seyn.) [ A single imperfectly preserved specimen but distinguished by its granular spiral sculpture. Only the first 10 whorls of a single specimen, a little over 1" [inch?] represents a regular cone, which is exactly half as wide as it is long. The whorls are slightly stepped, rounded just below the suture, flattened and somewhat concave in the middle. The entire surface of the last whorl is covered with barely visible spirals, which have already disappeared on the earlier whorls. In front of (or below) the concave center, however, there are also first 1-2 clearer simple spirals and then 6 finely beaded ones, of which only the first can be followed slightly behind the suture on all whorls, while the suture runs into the second row of beads and becomes finely undulating. The last 2 continue into the aperture. (The outer edge of the aperture is missing; the canal at the bottom of which may have been rather long).]” (Bronn in Reiss 1862: 30).

Latin description. “ Testa conico-turrita, apice acuta, crassa et solida; anfractibus 10, angustis, spiraliter sulcatis, medio subconcavis, ad suturam saepe tumescentibus, contabulatis, saepe subgranulosis, inferne seriebus granorum minutorum duabus ornatis; sulcis tenuibus, confertis, impressis; ultimo aufractu satis magno, basi subdepresso, seriebus granulorum 6, distantibus, instructo; apertura magna , rotundato-ovata.” ( Mayer 1864: 65).

Discussion. Mayer (1864: 65) compared the single specimen from Santa Maria Island to Cerithium varicosum Brocchi, 1814 . The holotype is not complete, and it is missing the later teleoconch whorls and aperture. In its fine granulose sculpture, it is indeed most like Thericium varicosum , from the Pliocene to Lower Pleistocene Mediterranean, but in that species the fine spiral sculpture is not granulose, and varices run along the entire teleoconch. No varices are seen in the Azorean species. Moreover, in T. varicosum on intermediate and late teleoconch whorls, the central spiral becomes weakly tubercular. This does not occur in T. hartungi ( Mayer, 1864) , which is most like T. incultum (Mayer, 1862) , but differs in having weakly granular spiral. No further specimens are at hand to further characterise the species.

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

Figures

PLATE 1. A. Danilia pterostomus (Bronn, 1861), height 5.0 mm, width 4.0 mm, Forno da Cré (figure taken from Bronn in Hartung, 1861, pl. 19, fig. 2). B1-B2. Emarginula octaviana Coen, 1939, DBUA-F 487-1, height 1.8 mm, diameter 3.0 mm, Ponta do Castelo. C. Bolma cf. rugosa (Linné, 1767), DBUA-F 471-3, diameter 4.1 mm, Ponta do Castelo. D1-D5. Turbo hartungi Bronn 1861, DBUA-F 1295-1, height 9.0 mm, width 8.0 mm, Malbusca (east cave). E1-E3. Nerita cf. funata Dujardin, 1837, DBUA-F 917-1, height 4.0 mm, width 6.0 mm, Ponta do Castelo. F1-F2. Thericium crenulosum (Bronn, 1862), height 10.0 mm, width 6.0 mm, Ponta do Norte lighthouse, LNEG collection (unnumbered). G1-G2. Thericium hartungi (Mayer, 1862), height 29.0 mm, width 13.0 mm, Pinheiros (figure taken from Bronn in Reiss, 1862, pl. 1, fig. 11). H1-H2. Thericium incultum (Mayer, 1862), DBUA-F 1034-2, height 23.0 mm, width 10.0 mm, Macela viewpoint. I1-I2. Thericium incultum (Mayer, 1862), DBUA-F 1027-1, height 29.0 mm, width 11.0 mm, Malbusca II. J1-J2, K1-K2. Bittium miradouroense nov. sp., Holotype DBUAF 1034-5, height 6.8 mm, width 1.9 mm (J); Paratype DBUA-F 1034-6(1), height 5.3 mm, width 1.9 mm (K), Macela viewpoint. L1-L2, M1-M2. Bittium nov. sp., DBUA-F 488-2, height 4.5 mm, width 1.8 mm (L), height 4.2 mm, width 1.7 mm (M), Ponta do Castelo.

PLATE 2. A1-A2. Bittium nanum (Mayer, 1864), DBUA-F 1296-2, height 4.9 mm, width 2.0 mm, Malbusca. B. Tenagodus (Tenagodus) obtusus (Schumacher, 1817), DBUA-F 1283-2, height 12.0 mm, width 11.0 mm, Ponta do Castelo. C. Epitonium sp., DBUA-F 931-1, height 4.0 mm, width 2.8 mm, Pedra-que-pica. D1-D3. Janthina krejcii, SMF10135a, height 25.0 mm, diameter 32.0 mm, Macela viewpoint (pictures from Beu, 2017, fig. 26). E1-E3. Janthina typica (Bronn, 1861), DBUA-F-428, height 19.0 mm, diameter 21.0 mm, Ponta do Castelo, (pictures from Beu, 2017, fig. 25). F.Cheilea equestris (Linnaeus, 1758), DBUA-F 1283-1, diameter 30.0 mm, Ponta do Castelo. G1-G3. Hipponix sulcatus (Borson, 1820), DBUA-F 937-1, height 5.3 mm, diameter 14.0 mm, Ponta do Castelo. H1-H2. Euspira atlantica (Mayer, 1862), height 16.0 mm, diameter 19.0 mm, Ponta do Norte lighthouse, LNEG collection (unnumbered). I. Triphorid s.l., DBUA-F 471-5, height 3.2 mm, width 1.3 mm, Ponta do Castelo. J1-J2. Cerithiopsis cf. tubercularis (Montagu, 1803), DBUA-F 1023-1, height 3.0 mm, width 1.2 mm, Ponta do Castelo. K. Petaloconchus intortus (Lamarck, 1818), DBUA-F 946-2, height 13.0 mm, width 6.0 mm, Ponta dos Cedros. L. Thylacodes arenarius (Linnaeus, 1758), DBUA-F 869-1, height 33.0 mm, width 24.0 mm, Ponta dos Cedros. M1-M3. Alvania cancellata (da Costa, 1778), DBUA-F 1296-3, height 4.0 mm, width 2.2 mm, Malbusca.