Teremitra fallax, 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 : 266-268

Teremitra fallax new species

Figures 2 O, 15J–M, 16D–F

Type material. Holotype (lv) MNHN 26458.

Type locality. Solomon Islands, 10°13'S, 161°29'E, 381–383 m [ SALOMON 1 St. CP1837].

Material examined. Only known from the holotype.

Description ( Fig. 15 J–M). Shell small, elongated, terebriform, strong, with high elevated spire (LWL/SL 0.37) and attenuated short canal. Shell consisting of 1.25 protoconch whorls and 10 convex, imbricated, teleoconch whorls separated by distinct, impressed suture. Protoconch paucispiral, globular, smooth, diameter and height 600 Μm. Transition from protoconch to teleoconch clearly marked by appearance of teleoconch sculpture. Axial sculpture consisting of nearly straight, slightly opisthocline, ribs, 18–20 on penultimate whorl, 20–22 on last whorl. Spiral sculpture on adapical-most five teleoconch whorls consisting of three strong cords; after 5th whorl, subsutural cord subdivided in two closely spaced cords, thus 6th to penultimate whorls with four cords; last whorl with 7 major cords and 7–8 smaller cords on canal. Axial ribs forming beaded intersections with cords. Aperture narrow elongate, low (AL/SL 0.27). Columella with two relatively pronounced, oblique folds, better seen when shell is slightly turned counter clockwise. Inner lip covered with thin off-white glossy callus. Siphonal canal broad and weakly delimited from aperture. Shell color off-white, slightly glossy under thin, transparent to light olive, smooth, peeling periostracum.

Measurements (holotype): SL 11.8 mm, LWL 4.4 mm; AL (with canal) 3.3 mm, SW 3.1 mm.

Radula of holotype ( Fig. 16 D–F) only partially retrieved, total length unknown. Rachidian with broad and short base, shallowly arched on anterior margin, and with large cusp emanating from posterior margin, with indistinct additional serration on both sides. Lateral teeth high triangular, scoop-shaped, attached by narrow base. Inner side adjoining the rachidians with 5–6 distinct, short denticles.

Distribution. Known only from the Solomon Islands in 381– 383 m.

Etymology. The name reflects the possible confusion with T. efatensis in the absence of protoconch.

Remarks. Teremitra fallax is very similar to T. efatensis but can be distinguished by its paucispiral protoconch. In the absence of protoconch it is nearly impossible to discriminate between the two species, especially since the variability of the teleoconch is not known in T. fallax . Nevertheless, the teleoconch whorls seem to be more imbricated in T. fallax ; in the latter, there are also four spiral cords on penultimate and last whorls, instead of three in T. efatensis , and the adapical-most subsutural cords are more closely spaced.

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 15. Shells of Teremitra efatensis (Aubry, 1999) (A – I) and T. fallax n. sp. (J – M). Teremitra efatensis (Aubry, 1999) (A – I). A – C. Holotype (MNHN 2798), SL 10.75 mm. D – E. Paratype (MNHN 2799), Vanuatu, MUSORSTOM 8, st. DW 1045, SL 9.4 mm (radula illustrated). F – G. Paratype (MNHN 2817), Vanuatu or SW New Caledonia, SL 10.2 mm. H – I. Fiji islands, Lau Ridge, Vanua Balavu, BORDAU 1, st. DW 1432, SL 10.0 mm. Teremitra fallax n. sp. (J – M), holotype, SL 11.8 mm. All shells at the same scale.

FIGURE 16. Radulae of Teremitra (A – F) and Vaughanites? superstes n. sp. (G – H). A – C. Teremitra efatensis, paratype, Vanuatu, MUSORSTOM 8, st. DW 1045, 16 º 54 ' S, 168 º 20 ' E, 459 – 488 m, SL 9. 4 mm. A. Central part of the membrane, dorsal view. B. Enlarged part of bending plane. C. Entire radular membrane. D – F. Teremitra fallax n. sp., holotype. D. Dorsal view of the central part of the radular membrane. E. Enlarged rachidian teeth. F. Enlarged lateral teeth. G – H. Vaughanites? superstes n. sp., holotype. G. Dorsal view of the central part of the radular membrane. H. Enlarged part of bending plane to show the lateral teeth.