Cylichna sp.

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 : 93

Cylichna sp.

Plate 6 H 1 -H 2

Santa Maria material examined. Maximum height 10.0 mm, width 5.0 mm. DBUA-F 1034-1 (78), Macela viewpoint, Santa Maria Island, Azores, Touril Complex, Lower Pliocene.

Description. Shell small to medium sized, relatively solid, ovate-cylindrical. Last whorl making up entire shell height, rounded at apex and base, narrowly umbilicate adapically. Aperture entire height, elongate, narrow adapically reaching slightly higher than apex, widening adapically, rounded adapically. Columella short. Columellar callus thickened, sharply delimited with small fold delimiting medial border of siphonal canal, not extending to parietal area.

Discussion. Cylichna sp. clearly differs from the European Miocene to recent C. cylindracea ( Pennant, 1777) and the Lower to Upper Miocene Atlantic C. pseudoconvoluta ( d’Orbigny, 1852) in being thicker shelled, less cylindrical, and more ovate. It is closely similar to C. ligeriensis (Glibert, 1952) from the Atlantic Middle and Upper Miocene of France, but that species tends to be narrowly swollen or subangular mid-whorl (see Landau et al. 2020a: pl. 19, figs. 1-3).

Distribution. Lower Pliocene: Atlantic, 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.

PLATE 6. A1-A2. Conus s.l. sp. A, DBUA-F 1292-1, height 19.0 mm, diameter 13.0 mm, Ponta dos Frades. B. Tomellana sp., height 25.0 mm (apical fragment), Ponta do Norte lighthouse, LNEG collection (unnumbered). C, D. Crassopleura maravignae (Bivona, 1838), height 12.0 mm, width 4.5 mm, Pinheiros (figure C taken from Bronn in Reiss, pl. 1, fig. 9 and figure D taken from Mayer, 1864, pl. 6, fig. 50). E1-E2. Psilaxis simplex (Bronn, 1831), DBUA-F 828-3 height 1.5 mm, width 4.5 mm, Ponta dos Frades. F. Mathilda quadricarinata (Brocchi, 1814), DBUA-F 1023-2, height 1.9 mm, width 1.1 mm, Ponta do Castelo. G1-G2. Acteon semistriatus (Férussac, 1822), DBUA-F 191-9, height 7.3 mm width 3.9 mm, Malbusca. H1-H2. Cylichna sp., DBUA-F 1034-1, height 10.0 mm, width 5.0 mm, Macela viewpoint. I1-I3. Roxania utriculus (Brocchi, 1814), DBUA-F 1027-2, height 8.2 mm, width 4.5 mm, Malbusca II. J1-J2. Scaphander lignarius (Linnaeus, 1758), height 27.0 mm, width 15.5 mm, unknown locality, LNEG collection (unnumbered). K1-K2. Pyrgostylus cf. abreui (Peñas & Rolán, 2000), DBUA-F 471-2, height 6.0 mm, width 3.0 mm, Ponta do Castelo. L1-L3. Clathrella clathrata (Philippi, 1844), DBUA-F 471-1, height 6.0 mm, width 7.0 mm, Ponta do Castelo. M, N. Ranella bicoronata Bronn, 1862 species inquirenda, height 19.0 mm, width 15.0 mm, Pinheiros (figure M taken from Bronn in Reiss, 1862, pl. 1, fig. 8 and figure N taken from Mayer, 1864, pl. 7, fig. 53).