Haedropleura secalina ( Philippi, 1844 )

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 : 43-44

Haedropleura secalina ( Philippi, 1844)

Figs. 7–12, 55–60

Pleurotoma secalinum Philippi, 1844: 170 , pl. 26, fig. 9.

Bellaspira secalina Nordsieck, 1977: 13 , pl. 1, fig. 8.

non Haedropleura secalina Bernasconi & Robba, 1984: 279 , pl. 3, fig. 2 (= H. formosa n. sp.). Haedropleura secalina Chirli, 1997: 36 , pl. 9, figs. 10–11, non fig. 12 (with synonymy). Haedropleura septangularis Ardovini & Cossignani, 1999: 67 , fig. 125.

Haedropleura secalina Cachia et al., 2001: 60 (in part), pl. 9, fig. 4 (with synonymy).

Haedropleura secalina Scarponi & Della Bella, 2004: 55 , figs. 84a, b, 91 (with synonymy).

Original description. [Pl. testa turrito-fusiformi, fulva; anfractibus rotundatis; costis longitudinalibus circa decem subflexuosis, subcontinuis, in ultimo anfr. abbreviatis; apertura oblonga, spira breviore; labro extus varicoso. Testa 4½’’’ alta, 1½’’’ lata, tenuissime transversim striata, (...)].

Type material. Only two syntypes from Naples are in the MNZHU, catalogue number: MB.Ga.459.1 and MB.Ga.459.2 (the original lot included 21 specimens). As the first syntype corresponds very well to the description, drawing and measurements cited by Philippi (1844: 170), it is here designated as the lectotype in accordance with the purpose of ensuring the name’s proper and consistent application of a taxon (see ICZN Code, 1999: article 74.7.3).

Type locality. Naples ( Italy).

Material examined. Pliocene – Zanclean: Villa Filicaia (Florence), 43°32’26”N, 10°55’38”E, 1 sh.; – Zanclean/early Piancenzian: Poggio alla Staffa (Siena), 43°26’40”N, 11°05’33”E, 5 sh.; – Piacenzian: La Speranza (Siena) 43°26’29”N, 11°06’01”E, 12 sh.; Melograni (Siena), 43°26’23”N, 11°03’05”E, 5 sh.; Terre Rosse (Siena), 43°19’32”N, 11°30’50”E, 1 sh. Pleistocene – Tarantian: Saracinello (Reggio Calabria), MGGC collection. Recent: Brindisi harbour ( Italy), 40°39’38”N, 17°57’30”E, 0m, 2 sh.; Campomarino ( Italy), 40°17’49”N, 17°34’13”E, - 5m, 3 sh.; Ceuta ( Spain), 35°52’38”N, 5°18’50”E - 16m, 8 sh.; Naples ( Italy), MNZHU collection, 2 sh.; Porto Cesareo ( Italy), 40°16’14”N, 17°52’34”E, - 4m, 3 sh.; Procida ( Italy), 40°45’06”N, 14°00’16”E, - 4m, 9 sh. and 1 spm.; St. Florent ( France), 42°40’35”N, 9°17’31”E, - 5m, 3 sh.

Distribution. Fossil specimens cited from the Miocene of the Loire Basin, France ( Glibert 1954) need further investigations. Upper Miocene (Tortonian) material from Piedmont, Italy ( Bernasconi & Robba 1984) is not attributable to this species. The lectotype of H. secalina has a paucispiral, papillate protoconch of 1.5 whorls (see Appendix 1), whereas the material from Piedmont has a multispiral mamillate protoconch of ~3 whorls. Haedropleura secalina is present, even if not very abundant, in the Plio–Quaternary of Italy ( Ruggieri 1948; Chirli 1997; Scarponi & Della Bella 2004). In the living fauna, H. secalina is known with certainty from the entire Mediterranean Sea and from the neighbouring Atlantic ((Madeira) Nordsieck 1977; Cachia et al. 2001).

Remarks. Haedropleura secalina has a solid, glossy, fusiform shell with a paucispiral, papillose protoconch (1.4 to 1.8 whorls; average diameter 0.64 mm, SD= 0.04 mm; see Appendix 1), indicating a non-planktotrophic larval phase. The protoconch is smooth, except for scanty punctate markings present near the suture and an obsolete, narrow axial fold marking the transition to the teleoconch (faint wrinkles are also present at the teleoconch transition on some specimens).

The teleoconch consists of max. ~7 whorls, regularly convex on their abapical half and slightly concave on their adapical part. The axial sculpture is very close to that of H. septangularis even though the ribs are more numerous and slender (8–11 on the last whorl; see also Appendix 1).

The aperture is elongate with a small parietal callus, ending in a poorly defined, very wide anterior canal. For features of the animal we refer to Cachia et al. (2001).

Haedropleura secalina has been long synonymised with H. septangularis , despite being readily diagnosed by its paucispiral protoconch (on average 1.5 whorls, SD=0.1). This is not surprising, especially during the 19th century where protoconch features were commonly overlooked. Indeed, the teleoconch outline, outer lip, anal sinus and sculpture show strong affinities to those of H. septangularis . If the protoconch is missing, only a few teleoconch features (unfortunately showing a certain degree of overlap) are useful to discriminate between the two species. H. secalina has a higher number of narrower axial ribs and the anterior canal is wider but less well-defined. However, with complete specimens the protoconch is a useful diagnostic feature that allows immediate separation of the two species. The specimen cited by Bernasconi & Robba (1984) as H. secalina from the Tortonian and Early Pliocene of Italy we consider to belong in H. formosa n. sp.