Crassispira somalica, Morassi, Mauro & Bonfitto, Antonio, 2013

Morassi, Mauro & Bonfitto, Antonio, 2013, Four new African turriform gastropods (Mollusca: Conoidea), Zootaxa 3710 (3), pp. 271-280 : 277-278

Crassispira somalica sp. nov.

Figures 1 . Q–S

Type material. Holotype (MZB 60076); 1 paratypes (MZB 60077); 1 paratype (MNHN-IM- 2012-2534).

Type locality. Offshore Mogadishu ( Somalia), trawled by local fishermen at unknown depth in 1989–1990.

Material examined. The type material.

Description. Shell rather solid (fig. Q-R), elongate-ovoid (b/l 0.42–0.46; a/l 0.43–0.47) with strongly gradate spire, last whorl not or weakly excavated with a relatively short rostrum. Protoconch narrowly domed of about 1¾ whorls, termination ill-defined, surface eroded. Protoconch diameter: about 1.2 mm. Teleoconch of 6–7 whorls with distinct, rounded shoulder at mid-whorl height, suture moderately deep bordered by a moderately strong, undulating subsutural fold. Sutural ramp wide, shallowly concave. Sculpture of broad, rounded, slightly opisthocline axial ribs extending from abapical suture to shoulder, rapidly vanishing on sutural ramp. Axial ribs separated by interspaces narrower than them, extending across upper part of base on last whorl. Seven to 8 axial ribs on penultimate whorl, increasing to 8–9 on last whorl (including a varicoid rib at level of outer lip). Spiral sculpture of shallowly incised grooves: 4–6 between shoulder and abapical suture on later two teleoconch whorls. Last whorl with 7–10 grooves on base and 5–7 cords on the rostrum. Whorls covered by dense, relatively rough axial growth lines particularly evident on sutural ramp. Aperture narrow, elongate-ovate. Columella straight with a thick callus, its outer edge free, fasciole strong, false umbilicus deep; parietal region with a low, rounded nodule at suture not significantly constricting opening of anal sinus. Siphonal canal short, narrow, deep, its anterior tip notched. Outer lip not or only feebly crenulated, preceded by a broad varix. No stromboid notch. Anal sinus relatively shallow, openly U-shaped with diverging sides. Color moderate brown with yellowish-white first teleoconch whorl and protoconch. Dimensions: Holotype: 21 x 8.9 mm, aperture height 9.2 mm; paratype (MZB): 20 x 9.2 mm, aperture height 9.5 mm (decollated); paratype (MNHN): 19.4 x 8.6 mm, aperture height 8.9 mm.

Etymology. Alluding to the fact that the new species is described from off Mogadishu ( Somalia).

Remarks. Crassispira somalica sp. nov. represents the first Recent species described from eastern Africa bearing “typical” Crassispira features. The new species differs distinctly from the few Tertiary Crassispira species reported from eastern Africa and the West Indian Ocean. In particular, Crassispira jamviniensis Cox, 1927 from the Miocene of Pemba Island has a narrower shell with well developed sculpture of numerous raised spiral cords rather than grooves. Harzhauser (2007) reported an undescribed Crassispira species from the Late Miocene of Oman, which differs from Crassispira somalica sp. nov. in possessing a much narrower and higher spire, more prominent subsutural fold, more deeply excavate sutural ramp and more deeply incised spiral grooves. The very variable European Tertiary Crassispira pustulata (Brocchi, 1814) may resemble C. somalica in shape and type of spiral sculpture, but the former has more deeply incised spiral grooves, more prominent subsutural fold and longer siphonal canal. Among described Recent species, Crassispira somalica sp. nov. is reasonably comparable only to the west African members of the genus. The new species resembles Crassispira consociata (E. A. Smith, 1877) in shape, dimensions (20.4 mm in length for the holotype) and number of axial ribs but otherwise differs in type of spiral sculpture (spiral grooves rather than spiral cords forming nodules at points of intersections with the axial ribs) and color (moderate brown rather than light brown to cream but Fernandes et al., 1995: 296 also reported almost white shells). Apart from the difference in type of spiral sculpture, the new species is further distinguished from other west African species such Crassispira carbonaria (Reeve, 1843) and Crassispira funebralis Fernandes, Rolán & Otero-Schmitt, 1995 in its much smaller dimensions (up to 21 mm versus 30 mm or more in length) and in possessing a lighter color (moderate brown versus dark brown-blackish).

Figures

FIGURE 1. A – H. Tropidoturris vizcondei sp. nov. A – B. Holotype (MNHN 26614), 11.1 x 4.3 mm. C – H. Paratype (MZB 60071). C. Shell, scale bar 1 mm. D. Penultimate whorl, scale bar 500 µm. E. Surface microsculpture, scale bar 40 µm. F – G. Protoconch, scale bar 200 µm. H. Microsculpture of protoconch, scale bar 100 µm. I – K. Iredalea adenensis sp. nov. I – J. Holotype (MZB 60072), 17.2 x 7.7 mm. K. Penultimate whorl. L – P. Buchema shearmani sp. nov. L – M. Holotype (MZB 60073), 9.9 x 3.5 mm. O. Protoconch. P. Detail of penultimate whorl. Q – S. Crassispira somalica sp. nov. Q – R. Holotype (MZB 60076), 21 x 8.9 mm. S. Penultimate whorl.