Hortia solitaria, 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

Hortia solitaria new species

Figures 2 N, 10D–E

Type material. Holotype MNHN 25727.

Type locality. Southern Madagascar. 24º23’S, 47º32’E, 400 m [ ATIMO VATAE, st. DW3525].

Material examined. Known only from the holotype.

Description (holotype) ( Fig. 10 D–E). Shell small, narrowly fusiform, with elevated spire (LWL/SL 0.55) and attenuated, medium long canal. Shell consisting of 1.25 protoconch and 5.2 slightly convex teleoconch whorls with deeply impressed suture. Protoconch paucispiral, bulbous, smooth, diameter 680 Μm, height 1 mm, separated from teleoconch by 2–3 fine, arched folds. Besides numerous very fine growth lines, axial sculpture consisting of narrow, nearly orthocline ribs, running from suture to suture on spire whorls, and becoming obsolete on shell base at transition to canal, 11 ribs on penultimate and 12 on last whorl. On spire, spiral sculpture consisting of a narrow subsutural cord and two main, regularly spaced, cords. Ribs and cords form very regular cancellation with small rounded beads on their intersections. Last whorl with 4 strong cords and 7 finer, and more closely spaced ones, on canal. Aperture medium high, narrow elongate, 0.36 (together with canal) of SL. Outer lip broken, concave at transition to long and narrow canal. Columella short, slightly convex, without columellar plait. Callus narrow, of thin transparent glaze overlying parietal region. Siphonal notch not observed. Canal partially broken, well differentiated from aperture, narrow, long, abaxially recurved.

Measurements: SL 6.5 mm, LWL 2.4 mm, AL (with canal) 2.5 mm, SW 3.6 mm.

Distribution. Known only from the type locality, off Southern Madagascar.

Etymology. From the Latin adjective, solitarius —alone, isolated, with reference to the geographical isolation of this species.

Remarks. Hortia solitaria stands apart from other species of Hortia by its bulbous protoconch and its sculpture forming a regular, reticulated pattern. The Eocene Hortia priabonica has a similar pattern but differs in having three spiral cords on adapical teleoconch whorls, instead of two in H. solitaria . In addition, these two species differs markedly in protoconch morphology.

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 10. Hortia pseudotaranis n. sp. A – B. Holotype, SL 8.4 mm. C. BIOGEOCAL, st. KG 227, 21 º 33 ’ S, 166 º 24 ’ E, 500 m, SL 6.3 mm. Hortia solitaria n. sp. D – E. Holotype, SL 6.5 mm.