Vesicomya nakaii Okutani, 1962

Kiel, Steffen, Aguilar, Yolanda M. & Kase, Tomoki, 2020, Mollusks from Pliocene and Pleistocene seep deposits in Leyte, Philippines, Acta Palaeontologica Polonica 65 (3), pp. 589-627 : 607

Vesicomya nakaii Okutani, 1962

Fig. 19A .

1962 Vesicomya nakaii sp. nov.; Okutani 1962: 22, pl. 4: 1a.

2000 Vesicomya nakaii Okutani, 1962 ; Okutani 2000: 997, pl. 496: 1.

Material.—One left valve on small block from the Pleistocene of Cambantug Point: NMNS PM 28413 (L = 8.0 mm, H =

7.3 mm).

Remarks.— Cosel and Salas (2001) considered V.nakaii as belonging to Isorropodon , but the species has a distinct lunular incision and hence belongs to Vesicomya . The specimen illustrated here from Cambantug Point has the posterior ridge and truncate posterior margin of V.nakaii , whereas V.margotae from Liog-Liog Point is posteriorly more elongated. The specimen clearly shows a lunular incision. Unfortunately, the hinge of our specimen is concealed in rock matrix.

Stratigraphic and geographic range.—Early Pleistocene: Leyte, Philippines. Recent: west coast of Kyushu, Japan.

Figures

Fig. 19. Small vesicomyid bivalves from late Pliocene (B–D, Liog-Liog Point) and early Pleistocene (A, E, Cambantug Point) seep deposits in Leyte, Philippines. A. Vesicomya nakaii Okutani, 1961, NMNS PM 28413, isolated left valve, view on outer side. B–D. Isorropodon cf. perplexum Sturany, 1896. B. NMNS PM 28414, small left valve, outside view (B1) and dorsal view (B2). C. NMNS PM 28415, isolated left valve, insight view (C1); close-up on hinge (C2). D. NMNS PM 28416, isolated right valve, view on outer shell surface. E. Isorropodon cf. perplexum Sturany, 1896, NMNS PM 28417, left valve with shell broken off, showing anterior adductor muscle scar.