Galeodinopsis tiberiana ( Coppi, 1876 )

Garilli, Vittorio & Parrinello, Daniela, 2014, Taxonomy and palaeobiogeography of the Cenozoic Euro-Mediterranean rissoid gastropod Galeodinopsis and its relationship with close genera, Acta Palaeontologica Polonica 59 (2), pp. 379-406 : 396-398

Galeodinopsis tiberiana ( Coppi, 1876)

Figs. 2 , 14A–C, F, G .

1862 Rissoa tuba nov. sp.; Doderlein 1862: 17 (nomen nudum).

1876 Rissoa Tiberiana nov. sp.; Coppi 1876: 201–202.

1990 Manzonia fariai nov. sp.; Rolán and Fernandes 1990: 64–65, pl. 1: 4–6.

1

3

4

1994 Alvania (Alvania) tiberiana ( Coppi, 1876) ; Bernasconi and Robba 1994: 79–80, pl. 4: 1, 2.

1999 Alvania fariai ( Rolán and Fernandes, 1990) ; Gofas 1999: 88–89, figs. 39–42.

2004 Alvania fariae ( Rolán and Fernandes, 1990) ; Landau et al. 2004: 41, pl. 7: 3, 4.

2008 Galeodinopsis tiberiana ( Coppi, 1876) ; Garilli 2008: 43, figs. 90–99.

Type material: More than 100 possible syntypes (not seen) in Coppi coll., at MPOB, IPUM 13721 from the Pliocene of Emilia Romagna, N Italy .

Type locality: “Tagliata” (see Garilli 2008: 43), Gagliardella , Maranello, Modena, Emilia Romagna, N Italy .

Type horizon: Coppi (1876: 202) reported “tabiano” at “Tagliata”, which may be referred to the Zanclean–Piacenzian terrigenous succession of the Emilia Romagna Apennines .

Material studied.—Those shells listed by Garilli (2008), including 31 Recent shells in MNHN, from the coasts of West Africa, originally classified as Alvania fariai ( Rolán and Fernandes, 1990) ; 205 shells in MF, some at MZPD Mal 2034–2035, from different Italian Neogene sites including type locality (“La Tagliata”, Maranello, Modena, N Italy), most of them originally identified as Alvania tiberiana Coppi, 1876 ); 44 shells at MGUP, Doderlein coll., from the Mio-Pliocene of N Italy, originally identified as Rissoa tuba Doderlein (nomen nudum); 33 shells ex AR, as Alvania tiberiana, MZPD Mal 2032 , from the Pliocene of Altavilla Milicia, Palermo, Sicily. For measurements of the shells housed in MNHN see Gofas (1999), who cited this species as A. fariai ( Rolán and Fernandes, 1990) .

Description.—Shell conical, sturdy, reaching 3.75 mm in height and 2.75 mm in width. Ht/W ratio 1.3–1.5. Protoconch multispiral, conical, with 2–2.2 convex whorls, nucleus rather immersed. Protoconch 1 of about 0.7–0.8 whorls, with netted sculpture, consisting of 7–8 very thin spiral lirae and numerous, irregular, short, very narrow axial segments occurring in interspaces between lirae. Protoconch 2 sculptured with very small, sparse granules, fused into 2–4 discontinuous ridges on central and abapical portions of latter part of last whorl. Some groups of granules form very short, prosocline segments on central area, mainly close to protoconch/teleoconch transition, which is marked by thin, quite sinuous lip. Teleoconch of 3–3.5 convex whorls, sculptured with a primary pattern of strong, slightly sinuous, opisthocline ribs; 12–14 (rarely 15) on penultimate whorl, becoming very weak or lacking towards base. Ribs covered with secondary spiral sculpture, formed by narrow, flat cords; 3, 4–5 and 8–10 (rarely 11–13) cords on first, penultimate and last whorls, respectively. Much weaker subsutural cord present on some specimens. Cords bear pitted microsculpture, consisting of microscopic subcircular pores forming 8–10 spiral alignments. Numerous, closely spaced, very fine spiral ridges occur between cords, formed by rough prismatic, tooth-like elements, extending perpendicularly from shell surface. At their base, each ridge has a lamella-like expansion, which covers the interspaces between two ridges. Weak subsutural cord lacking pitted surface, consisting of raised, very fine threads. Last whorl inflated, well-expanded, 0.6 to 0.75 of total shell height, many specimens bearing 1 or 2 varices with angles from about 100° to 270°, just before the outer lip on most specimens. Aperture ovate, very rounded anteriorly, weakly angulated posteriorly, comprising about 0.40–0.55 and about 0.7–0.75 (rarely about 0.6) of total shell and last whorl heights, respectively. Outer lip sinuous, weakly opisthocline; internally smooth, with thin rim on its edge; externally with very marked varicose swelling, covered with spiral sculpture, with narrow ridge on its base, towards aperture, forming double rim. Inner lip weakly curved, with very narrow columellar thickening, forming obsolete umbilical chink. Recent specimens white. After Garilli (2008), modified.

Stratigraphic and geographic range.— Galeodinopsis tiberiana lives in the eastern Atlantic, from Mauritania to northern Angola (see also Garilli 2008, with references). In the Mediterranean area it occurs in the Miocene (Tortonian) of northern Italy (northern Apennines) and the Pliocene of northern, central and southern Italy, of southern Spain, and of Algeria. In the Atlantic, it is recorded from the Portuguese Pliocene (Piacenzian) of the Mondego Basin ( Garilli 2008, with references).

Figures

Fig. 2. Rissoid gastropod Galeodinopsis tiberiana (Coppi, 1876), type species of Galeodinopsis Sacco, 1895 from Rio Grizzaga sands, Gagliardella, Fogliano, Maranello, Modena, N Italy, type locality, Piacenzian, Pliocene. A. Specimen ex MF, MZPD Mal 2035a, in apertural view. B. Specimen ex MF, MZPD Mal 2035b, in dorsal view. C. Specimen ex MF, MZPD Mal 2035c showing typical Manzonia-like teleoconch microsculpture (C 1) and detail of protoconch 1 with netted sculpture (C 2). Black arrows indicate the protoconch 1/protoconch 2 boundary. Scale bars: A, B, 1 mm; C, 20 μm.

Fig. 14. Rissoid gastropods Galeodinopsis tiberiana (Coppi, 1876) (A–C, F, G) and G. cf. tiberiana (D, E), from the Neogene of the Mediterranean area. Altavilla Milicia, Palermo, NW Sicily, Late Zanclean–early Late Piacenzian, Pliocene (A, D, E); Stirone River, San Nicomede, Parma, N Italy, Pliocene (B); Rio Grizzaga sands, Gagliardella, Fogliano, Maranello, Modena, N Italy, Piacenzian, Pliocene (C, F, G). A. Specimen ex AR, MZPD Mal 2032, in apertural view, showing the typical G. tiberiana-morph. B. Specimen ex MF, MZPD Mal 2034 in profile view, showing the sinuous outer lip curved backwards in the lower part. C. Specimen ex MF, MZPD Mal 2035d, in apertural view, showing more axial and spiral elements. D. Specimen ex AR, MZPD Mal 2033a, in apertural (D 1), profile (D 2), and dorsal (D 3) views, somewhat transitional between specimen as in C and galeodiniform specimens as in E and in Fig. 15; protoconch in profile view (D 4). E. Galeodiniform specimen ex AR, MZPD Mal 2033b, in apertural (E 1) and profile (E 2) views, tentatively assigned to G. tiberiana. F. Specimen ex MF, MZPD Mal 2035e, showing detail of teleoconch sculpture with marked axial ribs. G. Specimen ex MF, MZPD Mal 2035f, showing protoconch in profile view. Black and white arrows indicate the protoconch 1/protoconch 2 and protoconch/teleoconch boundaries, respectively. Scale bars: A–C, D –D , E, 1 mm; D , F, G, 100 μm.