Lucinoma canudai, Kiel & Aguilar & Kase, 2020

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 : 602-603

Lucinoma canudai sp. nov.

Fig. 14 . Zoobank LSID: urn:lsid:zoobank.org:act:AD227C3A-40D4-45BC-B82A-F075D98C6810

Etymology: In honour of Francisco Canuda (Mines and Geosciences Bureau of the Philippines) for his invaluable assistance with field work. Type material: Holotype NMP-2167, articulated, inflated specimen with attached burrow. Paratypes: three specimens (NMNS PM 28157– 28159) from the type locality.

Type locality: Cambantug Point , Leyte, Philippines .

Type horizon: Lower Pleistocene part of the Bata Formation .

Material.—The type material only.

Dimensions (in mm).—NMP-2167, L = 77.0, H = 71.3, W = 50.3 (articulated).

Diagnosis.—Large, well-inflated Lucinoma , outline angular, umbones blunt, surface sculpture of numerous densely spaced, sharp commarginal ribs, several smaller sharp ridges in interspaces; distinct anterior ridge; posterior sulcus well-developed, lunule long, narrow; ligament long, deeply sunken.

Description.—Large, inflated shell; umbones elevated, blunt; greatest width at middle of shell; anterodorsal margin short, nearly straight, with broad angulation at transition to anterior margin; elevated, blunt ridge running from umbones to anterior end of shell, producing distinct anterodorsal area; posterior area broad, bordered by deep sulcus and distinct ridge running from umbones to posteroventral shell margin; ventral shell margin between ends of those two ridges evenly convex; escutcheon narrow lanceolate, ligament deeply sunken; lunule elongate, deep; surface sculpture of densely spaced, alternating, sharp commarginal ribs.

Remarks.— Lucinoma canudai and also L. velosoi sp. nov. and L. tinagoensis sp. nov., described below), are remarkably more inflated than many species of Lucinoma , both extant ( L. yoshidai Habe, 1958 , L. kastoroae , and L. dulcinea ) and fossil ( L. galathea Marwick, 1953 , L. gracilistriata Hirayama, 1954 , L. shinokii Hirayama, 1954 ) ( Marwick 1953; Hirayama 1954; Habe 1958; Okutani and Hashimoto 1997; Cosel and Bouchet 2008; Glover and Taylor 2016). Lucinoma canudai differs from the two other strongly inflated Lucinoma species reported here ( L. velosoi and L. tinagoensis ) by its blunt anterior ridge and corresponding broad anterodorsal area, and its much deeper posterior sulcus. Lucinoma saetheri Amano, Little, and Campbell, 2018 from the lower Miocene of New Zealand differs from L. canudai by lacking lamellar sculpture and by having smaller umbones ( Amano et al. 2018).

Stratigraphic and geographic range.—Early Pleistocene, Leyte, Philippines.

Figures

Fig. 14. The lucinid bivalve Lucinoma canudai sp. nov. from the Pleistocene Cambantug Point seep deposit, Leyte, Philippines. A. Holotype NMP-2167, large, articulated specimen with attached, filled burrow; outer surfaces of right (A1) and left (A2) valves; dorsal side (A3). B. Paratype NMNS PM 28157, small specimen showing ligament nymph of left valve. C. Paratype NMNS PM 28158, small specimen with remnants of two cardinal teeth in the left valve.