Hortia marshalli, Kantor, Yuri, Lozouet, Pierre, Puillandre, Nicolas & Bouchet, Philippe, 2014

Kantor, Yuri, Lozouet, Pierre, Puillandre, Nicolas & Bouchet, Philippe, 2014, Lost and found: The Eocene family Pyramimitridae (Neogastropoda) discovered in the Recent fauna of the Indo-Pacific, Zootaxa 3754 (3), pp. 239-276 : 258-261

Hortia marshalli new species

Figures 2 K, 11, 12A–D

Turridae sp. 74— Spencer et al. 2009: 211.

Type material. Holotype NMNZ M. 060448; paratypes: 4 NMNZ M. 310254, 1 MNHN IM- 2012-2525.

Type locality. New Zealand, South Island, SE of Cape Campbell, 42º00.80’S, 174º41.00’E, 939–1019 m.

Material examined. New Zealand, South Island: SE of Cape Campbell, 42º00.80’S, 174º41.00’E, 939–1019 m, R/V Tangaroa , 14.01.1979, 1 lv, 10 dd (holotype and 4 paratypes) ( NMNZ); northern Bounty Trough, 45º24.20’S, 173º59.80’E, 1373 m, R/V Tangaroa , 27.10.1979, 1 lv (paratype MNHN, radula examined) ( NMNZ M.307883); northern Bounty Trough, 45º24.20’S, 173º59.80’E, 1386 m, R/V Tangaroa , 27.11.1979, 1 dd ( NMNZ M.307884); Bounty Trough, 45º48.80’S, 174º30.50’E, 1588 m, R/V Tangaroa , 26.10.1979, 1 dd ( NMNZ M.307882).

Description (holotype) ( Fig. 11 A–C). Shell small, narrowly fusiform, with high elevated spire (LWL/SL 0.53) and attenuated, medium long canal, consisting of ca 1.25 protoconch whorls and 5.25 slightly convex teleoconch whorls. Protoconch paucispiral, globose, smooth, corroded, diameter around 800 Μm, height 650 Μm. Suture shallowly impressed. On first teleoconch whorl, axial sculpture of about 15 closely spaced, slightly sinuous, narrow, nearly orthocline ribs; on subsequent whorls axial sculpture limited to growth lines, some more raised and forming small beads when intersecting the stronger spiral elements; growth lines progressively becoming more sinuous and, on latter teleoconch whorls (including penultimate and last whorls), delineating a rather deep, broad, anal sinus on whorl periphery. Spiral sculpture consisting of narrow and low, irregularly spaced cords, covering the entire shell surface; on adapical teleoconch whorls, 4 cords above periphery, a slightly higher one on periphery, producing weak angulation, and 3 below periphery; on penultimate whorl, 5 cords above periphery and 6 below peripheral cord; on last whorl 6 cords above periphery, one more raised peripheral cord and 24 cords below it, including canal. Interspaces between cords flat, of uneven width, from 1 to 3 times cords width. Aperture medium high, narrow elongate, 0.42 (together with canal) of SL. Outer lip partially broken, weakly concave at transition to narrow canal. Columella short, slightly concave, smooth. Callus narrow, of thin transparent glaze overlying parietal region. Canal well differentiated from aperture, narrow, medium long, abaxially recurved. Shell colour off-white. Periostracum thin, obscuring the sculpture (removed prior to photographing the shell), peeling.

Measurements (holotype): SL 10.6 mm, LWL 5.6 mm, AL (with canal) 4.5 mm, SW 3.5 mm.

Radula ( Fig. 12 A–B) examined in paratype (shell: Fig. 11 F–G, SL 12.4 mm, AL 5.6 mm). Medium long, about 490 Μm long (8.8% of AL), consisting of about 48 rows of teeth, 4–5 nascent, with strong alary processes embracing anterior part of odontophore. Rachidian teeth with broad base, strongly arched anteriorly, and large cusp with much smaller dent at the cusp base. Lateral teeth high triangular, shallow scoop-shaped, attached by narrow base to membrane. Inner side adjoining rachidian with small additional denticles, varying from row to row in number and prominence.

Distribution. New Zealand, off South Island, alive in 1019–1373 m, shells to 1588 m.

Etymology. The specific epithet honors our good colleague Bruce Marshall, the active New Zealand scholar and expert on molluscs.

Remarks. Paratypes are rather similar to holotype. They are covered with an easily peeling, fibrous periostracum, obscuring the sculpture. Shell color off-white to very light yellow. The largest specimen (paratype, Fig. 11 F–G) has SL 12.4 mm, LWL 6.9 mm, AL 5.6 mm, SW 3.9 mm. A juvenile paratype has a better preserved protoconch ( Fig. 11 H–I) consisting of 1.5 convex whorls, diameter 800 Μm, height 800 Μm, covered with microscopic spiral striae. Protoconch-teleoconch transition weakly differentiated, marked by the onset of 15, nearly orthocline, axial ribs, distinct from the growth lines recognizable by the anal sinus.

The three lots from Bounty Trough were collected at greater depths (1373–1588 m) and differ from specimens from the type lot in having slightly thinner shells with higher last whorl (about 0.6 SL), chalky surface and thinner periostracum. Two specimens have an intact outer lip, showing the shape of the anal sinus ( Fig. 11 K). The protoconch and adapical teleoconch whorls of these Bounty Trough specimens are strongly corroded, preventing detailed comparison, but the protoconch of these specimens seems taller. The radula ( Fig 12 C–D; shell: Fig. 11 L) of one such specimen appeared rather similar to that of the paratype, although lacking any inconspicuous lateral denticle on the central cusp of the rachidian. It is also longer (length 730 Μm, or 11.5% of AL vs. 8.8% in the paratype), and consists of more rows of teeth (70 vs. 48). We consider these differences as part of bathymetric variation within the species.

Hortia marshalli differs from its congeners by its finer spiral sculpture and very weak axial sculpture limited, on most teleoconch whorls, to slightly raised growth lines producing very small beads when intersecting the spiral cords.

Figures

FIGURE 2. Overview of fossil and Recent Pyramimitridae. A. Endiatoma quadricincta (Cossmann, 1883), MNHN. F. A 47757, Lower Eocene, France. B – C. Pyramimitra terebraeformis (Conrad, 1848), MNHN. F. J 08748, Middle Eocene, USA. D – E. Pyramimitra quadralirata Dockery, 1977, MNHN. F. A 47750, Middle Eocene, USA. F. Hortia priabonica n. sp., MNHN. F. A 47752, Upper Eocene, France. G. Hortia arriuensis Lozouet, 1999, MNHN. F. A 47751, Upper Oligocene, France. H. Hortia pseudotaranis n. sp., New Caledonia, SL 8.4 mm. I. Hortia macrocephala n. sp., New Caledonia, SL 10.4 mm. J. Hortia paradrillia n. sp., New Caledonia, SL 8.1 mm. K. Hortia marshalli n. sp., New Zealand, SL 10.6 mm. L. Hortia spenceri n. sp., New Zealand, SL 9.0 mm. M. Hortia aotearoa n. sp., New Zealand, SL 9.0 mm. N. Hortia solitaria n. sp., South of Madagascar, SL 6.5 mm. O. Teremitra fallax n. sp., Solomon Islands, SL 11.8 mm. P. Teremitra efatensis (Aubry, 1999), Vanuatu, SL 10.8 mm. Q. Teremitra? hortensis (Vinassa de Regny, 1898), Upper Eocene, France. R. Teremitra sp., Taiwan, SL 16 mm. S. Vaughanites? superstes n. sp., Philippines, SL 19.1 mm.

FIGURE 11. Hortia marshalli n. sp. A – C. Holotype, SL 10.6 mm. D. Paratype, SL 12.0 mm. E. Paratype, SL 12.1 mm. F – G. Paratype, SL 12.4 mm (radula examined, MNHN IM- 2012 - 2525). H – I. Paratype, SL 5.2 mm (H—enlarged protoconch). J – K. Northern Bounty Trough (NMNZ M. 307884), SL 8.8 mm. L. Northern Bounty Trough (NMNZ M. 307883), SL 12.0 mm. All shells (except I) at the same scale.

FIGURE 12. Radulae of Recent Hortia species. A – D. Hortia marshalli n. sp. A. Dorsal view of the central part of the radular membrane of paratype (MNHN IM- 2012 - 2525, shell on 11 F – G). B. Same, enlarged anteriormost part of radular membrane. C – D. Northern Bounty Trough (NMNZ M. 307883, shell on 11 L). C. Dorsal view of the central part of the radular membrane, D. Enlarged central and right lateral teeth. E – F. Hortia spenceri n. sp., holotype. E. Dorsal view of the central part of the radular membrane. F. Enlarged central and right lateral teeth.