Hipponix sulcatus ( Borson, 1820 )

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 : 39-40

Hipponix sulcatus ( Borson, 1820)

Plate 2 G 1 -G 3

* Patella sulcata Borson 1820: 185 .

Hipponyx [sic] granulatus de Basterot 1825: 62 , pl. 4, fig. 14.

Pileopsis granulosa Grateloup 1836: 279 , pl. 1, figs. 29-30.

Pileopsis granulosa Grat. —Grateloup 1847: 1, figs. 29-30.

Hipponyx sulcatus Borson — Mayer 1864: 54.

Gadinia sulcata (Borson) —Cossmann 1895: 145, pl. 6, figs. 20-22.

Amalthea? sulcata (Bors.) —Sacco 1895: 44, pl. 5, fig. 24.

Amalthea? sulcata var. pyramidata Sacco 1895: 45 , pl. 5, fig. 25.

Amalthea? sulcata var. subcrenulata Sacco 1895: 45 , pl. 5, fig. 26.

Amalthea? sulcata var. plioparva Sacco 1895: 45 , pl. 5, fig. 27.

Amalthea? sulcata var. dertonatulina Sacco 1895: 45 , pl. 5, fig. 28.

Hipponyx [sic] sulcatus (Borson) —Cossmann & Peyrot 1919: 522, pl. 14, fig. 64, pl. 15, figs. 12-15.

Hipponyx [sic] sulcatus (Borson) — Lozouet et al. 2001: 40, pl. 15, fig. 3.

non Amalthea sulcata Borson, 1820 — Glibert 1949: 20, pl. 12, fig. 13 (= Hipponix helveticus Cossmann & Peyrot, 1919 ).

non Hipponix sulcatus ( Borson, 1820) — Chirli & Linse 2011: 93, pl. 27, fig. 3. [= Hipponix bistriatus ( Grateloup, 1827) ].

Santa Maria material examined. Maximum height 5.3 mm, diameter 14.0 mm. DBUA-F 937-1 (1), DBUA-F 469- B (1), Ponta do Castelo, Santa Maria Island, Azores, Touril Complex, Lower Pliocene.

Description. Shell medium sized, solid, relatively depressed, patelliform, with an elliptical profile. Protoconch eroded in all specimens. Apex placed just posterior to center. Dorsal sculpture of rounded ribs (74 in Azorean specimen) of equal strength, cut by numerous concentric growth lines, making ribs tuberculose. Ventral aspect smooth, except for horse-shoe shaped muscle scar.

Discussion. A single well-preserved Hipponix specimen from the Azores is identical to specimens of Hipponix sulcatus ( Borson, 1820) , which was originally described from the Lower-Middle Miocene of the Colli Torinesi, Italy (NHMW collection). Cossmann & Peyrot (1919: 524) correctly noted that the Atlantic Lower-Middle Miocene Aquitanian-Langhian specimens from the Aquitaine Basin of France were identical to those from the Colli Torinesi (see also Lozouet et al. 2001: 40, pl. 15, fig. 3). These specimens are characterised by having coarse radial ribs strengthening toward the periphery and an apex placed on the dorsum just posterior to center. Glibert (1959: 201), considered the Atlantic Middle Miocene Langhian specimens from the Loire Basin conspecific.Numerous specimens at hand from several localities in the Loire Basin (Ferrière-Larçon, Pauvrelay, Mathelan: NHMW collection) suggests this is not correct. Apart from being smaller, as noted by Cossmann & Peyrot (1919) and Glibert (1959), the radial sculpture is finer, and the apex is more pointed and placed far more posteriorly, and in fully adult specimen, overhangs the posterior margin. These differences were already noted by Cossmann & Peyrot (1919: 324), who erected the variety helvetica for the Loire Basin form. We agree with Peyrot (1938: 88), in separating these smaller specimens, and elevate the name to full-species rank: Hipponix helveticus Cossman & Peyrot, 1919 .

Although a predominantly Lower and Middle Miocene Atlantic species, Sacco (1895), reported it from the Upper Miocene of Italy and the single Lower Pliocene Italian locality of Bussana Vecchia, Imperia, Liguria. We are not aware of any subsequent Pliocene references to the species, and it is not present in the Pliocene of the Estepona Basin. Hipponix bistriatus ( Grateloup, 1827) , which does occur in the Estepona Basin deposit ( Landau et al. 2004a: 69, pl. 18, fig. 2), differs in being less depressed, in having the apex overhanging the posterior margin, and finer axial sculpture consisting of ribs of alternating strength. Hipponix explicatus Landau, Marquet & Grigis, 2004a , also from the Estepona assemblages, is characterised by a peculiar shell without axial sculpture and a strongly disjunct last whorl, quiet unlike H. sulcatus , H. bistriatus or H. helveticus .

Chirli & Linse (2011: 93, pl. 27, fig.3) illustrated a specimen from the Pleistocene of Rhodes Island as H. sulcatus . The specimen illustrated is far less depressed than usual for the species, the apex is placed at the posterior margin and there is a secondary rib between each primary. It probably represents H. bistriatus .

Hipponix sulcatus seems to have survived into the early Pliocene in the Mediterranean, now known from a single locality in Italy (Sacco 1895), and in the Atlantic, in the Azores (this paper). These records probably represent relict populations that did not survive the cooling events at the end of MPPMU1.

Distribution. Lower Miocene: Atlantic (Aquitanian and Burdigalian), Aquitaine Basin, France (de Basterot 1825; Grateloup 1836, 1847; Cossmann & Peyrot 1919; Lozouet et al. 2001); central Proto-Mediterranean, Colli Torinesi, Italy ( Borson 1820; Sacco 1895). Upper Miocene: central Proto-Mediterannean, Italy (Sacco 1895). Lower Pliocene: Atlantic, Santa Maria Island, Azores ( Mayer 1864); central Mediterranean, Italy (Sacco 1895).

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 3. A. A1-A2. Alvania mediolittoralis Gofas, 1989, DBUA-F 962-2, height 2.1 mm, width 1.2 mm, Ponta do Castelo. B. Alvania sleursi (Amati, 1987), DBUA-F 471-4, height 2.0 mm, width 1.1 mm, Ponta do Castelo. C1-C2. Alvania sleursi (Amati, 1987), DBUA-F 962-3, height 3.2 mm, width 1.8 mm, Ponta do Castelo. D1-D3. Rissoina pusilla (Brocchi, 1814), DBUA-F 488-1, height 5.2 mm, width 2.1 mm, Ponta do Castelo. E1-E3. Macromphalina depressa (Boettger, 1907), DBUA-F 1023-3, height height 1.0 mm, width 1.8 mm, Ponta do Castelo. F. Calyptraea chinensis (Linnaeus, 1758), DBUA-F 926-1, diameter 18.0 mm, Malbusca 2. G1-G2. Schilderia utriculata (Lamarck, 1810), height 24.0 mm, width 15.0 mm, unknown locality, LNEG collection (unnumbered). H1-H3. Erato mayeri nov. sp., Holotype DBUA-F 1189-C, height 7.7 mm, width 5.3 mm, Pedra-que-pica. I1-I3. Erato mayeri nov. sp., Paratype DBUA-F 1291-1, height 8.9 mm, width 6.0 mm, Ponta dos Frades. J1-J4. Pseudopusula parcicosta (Bronn, 1862), DBUA-F 469-1, height 9.0 mm, width 6.5 mm, Ponta do Castelo.