Haedropleura formosa, Scarponi, Daniele, Bella, Giano Della & Ceregato, Alessandro, 2011

Scarponi, Daniele, Bella, Giano Della & Ceregato, Alessandro, 2011, The genus Haedropleura (Neogastropoda, Toxoglossa = Conoidea) in the Plio – Quaternary of the Mediterranean basin, Zootaxa 2796, pp. 37-55 : 44-46

Haedropleura formosa n. sp.

Figs. 19–27 , 64–66

Haedropleura sp. 1 Scarponi & Della Bella, 2004: 56, figs. 88a,b, 93. Haedropleura secalina Bernasconi & Robba, 1984: 279 , pl. 3, fig. 2.

Type material. Holotype and 14 paratypes (Appendix 1), in Della Bella Collection at MGGC (Bologna, Italy). Catalogue number 23459 (holotype) and 23460 (paratypes).

Type locality. Codrignano (Borgo Tossignano, Bologna), Italy, (see Ruggieri (1962) for information on the type locality).

Material examined. Pliocene – Zanclean: Villa Filicaia (Florence), 43°32’26”N 11°55’38”E, 1 sh. Plio/Pleistocene – Piacenzian/Gelasian: Pieve Vecchia (Pisa), 43°29’57”N 10°29’15”E, 1 sh. Pleistocene – Gelasian: La Sterza (Pisa), 43°30’11”N, 10°43’22”E, 3 sh.; Maiola (Bologna), 44°25’15”N 11°05’33”E, 4 sh.; – Calabrian: Codrignano (Bologna), 44°18’14”N, 11°38’55”E, 6 sh.

Description. Shell small (maximum length 11.2 mm, maximum diameter 4.7 mm), elongate-fusiform, solid, with conical spire (see Appendix 1). Protoconch multispiral (2.8–3.0 whorls; average diameter 0.84 mm, SD= 0.05 mm), with small, flattened tip and very convex, relatively wide remaining whorls (see Appendix 1). Protoconch mainly smooth except for punctate markings on last whorl, restricted to suture area. On last protoconch whorl, 3–5 arched, opisthocline axial plicae mark transition to teleoconch. Teleoconch glossy white when well-preserved, of max ~6.1 whorls, with high spire, whorl sides regularly convex below mid-whorl, straight or slightly concave over adapical half. Suture undulated by rib-terminations, slightly marginated. Aperture oblong, with parietal callus evident in specimens with>4 teleoconch whorls. Columellar lip straight, thin. Outer lip thin but backed by wide, round varix, present on all specimens with>4 teleoconch whorls; varix roundly arched, upper part spread forward, corresponding to broad, moderately deep subsutural sinus, then curving gently down, extending to ill-defined anterior siphonal canal; canal wide, with slight notch. Last whorl moderately to strongly rounded, especially in specimens with more than five whorls. Axial sculpture consists of slightly curved, rounded, opisthocline ribs and wellmarked growth lines. Axial ribs extend from suture to suture, prominent abapically, subdued and pinched adapically, 8–9 on spire whorls (see Appendix 1). Ribs on last whorl 8–9 on most specimens, reaching neck but not prominent towards base. Spiral sculpture consists of dense, close-set threads, wider towards base, narrower on anal fasciole, separated by very shallow, incised interspaces. Except for last whorl, spiral elements evident only on wellpreserved specimens.

Etymology. This species is named for its plump protoconch whorls.

Distribution. Haedropleura formosa n. sp. is known from sedimentary successions in Italy, surely from Zanclean to Calabrian (Plio–Pleistocene) (see above).

Remarks. Haedropleura formosa n. sp. displays all the principal characters of the genus Haedropleura . Furthermore, the teleoconch features studied overlap strongly (except for the number of axial ribs) with those of H. septangularis , the type species of the genus (see Appendix 1). However, the characteristic, taller protoconch outline coupled with its relatively large dimensions (highlighting a significant gap in protoconch morphometric measures) make H. formosa easily distinguishable from the type species ( H. formosa average protoconch length 0.84 mm, SD= 0.06 mm, vs. H. septangularis 0.64 mm, SD= 0.05 mm; see Appendix 1 for further details).

Figures

FIGURES 19 – 27. Haedropleura formosa n. sp. 19 – 21, # 54, Maiola (Bologna), Gelasian (Pleistocene); 22 – 24, # 46 holotype, 25 – 27, # 51 paratype, Codrignano (Bologna), Calabrian (Pleistocene). FIGURES 28 – 36. H. parva n. sp. 28 – 30, # 72, La Speranza (Siena), Piacenzian (Pliocene); 31 – 33, # 63 paratype, 34 – 36, # 62 holotype, Poggio alla Staffa (Siena), Zanclean (Pliocene). Scale bars 1 mm; # = shell number in Appendix 1.

FIGURES 64 – 75. SEM photographs of protoconch and of teleoconch details of fossil shells. SEM photos are apical and lateral views (scale bars = 0.1 mm). Details (right column) show ornamentation of last whorl of each shell between suture and aperture, corresponding to the sinus. FIGURES 64 – 66. Haedropleura formosa n. sp. 64 – 65, # 50 paratype, 66, # 46 holotype, Codrignano (Bologna), Calabrian (Pleistocene). FIGURES 67 – 69. H. parva n. sp. 67 – 68, # 65 paratype, 69, # 62 holotype, Poggio alla Staffa (Siena), Zanclean (Pliocene). FIGURES 70 – 72. Haedropleura sp. 1 70 – 71, # 81, 72, # 79, Pieve Vecchia (Pisa), Piacenzian / Gelasian (Plio / Pleistocene). FIGURES 73 – 75. Haedropleura sp. 2 73 – 74, # 84, Castell’Anselmo (Leghorn), Zanclean / Gelasian (Plio / Pleistocene); 75, # 82, Stirone River (Parma), Gelasian (Pleistocene). # = shell number in Appendix 1.