Timoclea keegani, Raines & Huber, 2012

Raines, Bret & Huber, Markus, 2012, 3217, Zootaxa 3217, pp. 1-106 : 86-88

Timoclea keegani sp. nov.

Figures 44 A–H

Veneridae — Luke, 1995: p. 106.

Chione sp. — Trego, 1997: p. 199.

Type Material. Holotype: LACM 3177, 1 articulated specimen, 10.2 mm x 9.1 mm, ( Figs. 44 A–D). Paratype 1–2: LACM 3178, 2 juvenile live taken specimens, 2–2.6 mm, from type locality. Paratypes 3–4: LACM 3179, 2 single valves, 5.2–10 mm, from EI, Mataveri Bay , 30–60 m. Paratypes 5–6: LACM 3180, 2 single valves, 4.2–4.6 mm, from EI, Hanga Roa, 80–100 m. Paratype 7: SIO M1448 , 1 RV, 8.7 mm x 7.6 mm, from EI, La Perouse Bay , 40– 100 m, 1957/58 Downwind Expedition (DWHD-76), ( Figs. 44 E–F) . Paratypes 8–12: Coll. BR, 5 single valves, 4.5–6.7 mm, from type locality. Paratypes 13–15: Coll. MHU, 3 single valves from EI, Mataveri Bay , 30-60 m, 5- 6.5 mm .

Type Locality. Dredged at 30–80 m in fine sand, off the western coastline near Tahai, Easter Island, 27°07’20” S, 109°26’30” W .

Description. A small, colorful Timoclea species , solid, with elevated umbones. Shell small (up to 10.2 mm in length), solid, ovate, equivalve, somewhat inflated. Umbones elevated well above the hinge line. Prodissoconch well defined, turned obliquely under the umbo and not visible in adults, P1 round, smooth, ca. 85 µm length by 77 µm height, P2 ovate with weak commarginal ridges, ca. 170 µm length by 140 µm height. Exterior surface of adult valves highly sculptured with pronounced radial cords crossed by commarginal ridges, which form small raised nodes at each intersection giving a scalloped appearance. Secondary intercalated radial cords near ventral margin. Lunule well marked, inset, commarginally striate. Interior margins crenulated, pallial sinus weak and shallow. Hinge strong, consisting of the typical three cardinals in each valve and additionally a strong anterior tubercle, occasionally divided into two portions. Color creamy white with irregular reddish orange blotches.

Comparative diagnosis. None of the known twenty-five Timoclea species from South Africa to Japan matches the new EI species. Young T. keegani may appear similar to a few other Indo-Pacific Timoclea species , namely, T. infans (E.A. Smith, 1885) , T. scabra ( Hanley, 1844) or T. siamensis (Lynge, 1909) , but all differ in shape, sculpture, color and hinge. The hinge of T. keegani is most similar to that found in T. mindanensis ( Smith, 1885) , but here the shape, sculpture and color differ. Lastly, the European type species, T. ovata lacks anterior tubercular teeth.

Remarks. There are no Timoclea species known from the Hawaiian Islands, nor have any been collected from the Marquesas Islands. A single valve from the 1957/58 Downwind Expedition, noted as Veneridae by Luke (1995) and Chione species by Trego (1997) in the SIO Benthic Collection, M1448 ( Figs. 44 E–F) is consistent with T. keegani .

Distribution. Timoclea keegani is commonly found at many locations off Easter Island, sublittoral from ca. 30–100 m — E1.

Etymology. The name given to this species is in honor of the senior author's son Keegan Raines.