Wareniconcha sp.

Kiel, Steffen, Fernando, Allan Gil S., Magtoto, Clarence Y. & Kase, Tomoki, 2022, Mollusks from Miocene hydrocarbon-seep deposits in the Ilocos-Central Luzon Basin, Luzon Island, Philippines, Acta Palaeontologica Polonica 67 (4), pp. 917-947 : 932-933

Wareniconcha sp.

Fig. 15 .

Material.— Three specimens from block F ( NRM Mo 192537–192539). Upper Miocene of the “shale quarry” within the Northern Cement Corporation quarry in Pangasinan province, Luzon, Philippines .

Dimensions (in mm).—NRM Mo 192539: L = 49.0, H = 34.0, W (single) = 13.0; NRM Mo 192538: L = 40.0, H = 33.0, W = 22.0; NRM Mo 192537: L = 44.0+, H = 41.0, W (single) = 15.0.

Description.—Medium-sized, moderately inflated, oval shell; umbones elevated, prosogyrate; blunt posterior ridge creating broad posterodorsal area, no escutcheon and lunule; hinge plate narrow, RV with three thick cardinal teeth arranged more-or-less parallel to dorsal shell margin.

Remarks.—The available specimens are too poorly preserved for species-level identification.

Vesicomyidae gen. et sp. indet. 1

Fig. 16A .

Material.— 15 specimens from block E ( NRM Mo 192438– 192453), many specimens on a rock sample from the NCC collection. Upper Miocene of the “shale quarry” within the Northern Cement Corporation quarry in Pangasinan province, Luzon, Philippines .

Dimensions (in mm).—NRM Mo 192439: L = 15.6, H = 13.0, W = 8.9; NRM Mo 192440: L = 20.8, H = 15.7; NRM Mo 192442: L = 23.2, H = 19.4; NRM Mo 192444: L = 22.3, H = 17.3, W = 12.4; NRM Mo 192446: L = 20.0, H = 14.6, W = 11.3.

Remarks.—This locally very abundant, small-sized vesicomyid defies a more precise classification because the available material does not show internal characters such as hinge, muscle scars and pallial line. It is smaller and more elongate than Pliocardia ballesterosi . Its overall shell outline is similar to that of Isorropodon cf. perplexum Sturany, 1896 , from Pliocene seep deposits in Leyte Island, Philippines ( Kiel et al. 2020a), but that species lacks a lunular incision, clearly visible in vesicomyid sp. 1 reported here.

Figures

Fig. 15. The vesicomyid bivalve Wareniconcha sp. from Upper Miocene seep deposits of the Amlang Formation in Pangasinan province, Luzon, Philippines. A. NRM Mo 192537, large, slightly disarticulated specimen, view on RV (A1), view on LV and RV hinge plate (A2), and close-up on RV hinge with cardinal teeth numbers indicated (A3). B. NRM Mo 192538, articulated, medium-sized specimen, view on LV (B1) and on dorsal side showing inflation and lack of lunular incision (B2).

Fig. 16. Small vesicomyid bivalves from Upper Miocene seep deposits of the Amlang Formation in Pangasinan province, Luzon, Philippines. A. Vesicomyidae gen. et sp. indet. 1, NRM Mo 192444, articulated specimen, view on LV (A1) and view on dorsal side showing lunular incision and ligament (A2). B. Vesicomyidae gen. et sp. indet.2, NRM Mo 192426, articulated specimen, view on LV (B1) and view on dorsal side showing lunular incision and escutcheon (B2).