New species, misidentifications and problematic taxonomy of some Atlantic South American marine mollusks: a review Author Simone, Luiz Ricardo L. text Papéis Avulsos de Zoologia 2024 2024-08-09 64 1 104 https://doi.org/10.11606/1807-0205/2024.64.031 journal article 10.11606/1807-0205/2024.64.031 1807-0205 14705562 Superorder Imparidentia Order Lucinida Superfamily Lucinoidea Family Lucinidae Genus Lucinoma Dall, 1901 Lucinoma apocalyptica new species ( Fig. 57 ) https://zoobank.org/ FCF81E9E-956D-43D3-9FE3-39799DA3A13B Type: Holotype MZSP 162656 , shell. Type locality: BRAZIL . Pará ; off Salinópolis, 01°04′N 46°18′W , 250 m [Femorale-Ex collection Vanin ; RV Oregon col., o.t., xi.1957 ] . Figure 57. Lucinoma apocalyptica holotype MZSP 162656 shell (L 79.3 mm): (A) left valve, outer view; (B) right valve, outer view; (C) whole dorsal view; (D) left valve, inner view; (E) Right valve, inner view; (F) hinge of both valves almost articulating, ventral view;(G) hinge,left valve, right view; (H) hinge, right valve, left view.Scales:= 10 mm. Diagnosis: N Brazilian species of large size (~ 80 mm ), thick walled. Sculpture simple, uniform, lacking undulations, carina or abrupt slope. Outline rounded. Umbo broad. Description: Shell ( Fig. 57 ), of ~ 80 mm ; outline rounded; walls heavy, thick. Color white, opaque. Maximum inflation ~half length ( Fig. 57C ). Umbones central, slightly prosocline,anterior to it slightly concave edges,posterior to it slightly convex edges. Anterior, ventral and posterior edges performing soft rounded profile ( Fig. 57A, B, D, E ); posterior slope very weakly undulated, less acuminated than anterior region. Sculpture concentric, low scales, rather irregular, discontinuous; interspaces equivalent to 3-4 times each scales′ width; sculpture uniform from umbo up to margins ( Fig. 57A, B ). Pre-umbonal lunula present ( Fig. 57C ), sculptures only by very narrow,crowd- ed, longitudinal lines. Ligament wide, mostly external, almost half of dorsal edge ( Fig. 57C ). Hinge ( Fig. 57 F-H) thick, ~8% of shell height; with pair of cardinal teeth in both valves, being anterior most tooth in right valve; posterior tooth in right valve and anterior tooth of left valve slightly bifid; weak anterior lateral tooth present, clearer in right valve ( Fig. 57G, H ); no detectable posterior lateral tooth. Ligament groove wide, from umbo up to almost posterior edge. Scar of anterior adductor muscle elongated, ~7 times longer than wide, situated ~18° in relation to vertical axis, ~13° in relation to adjacent pallial line. inner surface pure white, barely radially beaded ( Fig. 57D, E ). Scar of posterior adductor muscle elliptic, ~1.5 times longer than wide, with ~half of anterior muscle′s size. Scar of anterior pedal retractor muscle just superior and posterior to scar of anterior adductor muscle, rather rectangular, ~20 times smaller than adductor muscle. Pallial line complete, wide, anterior half nodulous; its anterior insertion in dorso-anterior edge of anterior adductor muscle edge; its posterior insertion in ventral end of posterior adductor muscle. Etymology: The specific epithet is based on the Church Latin ‘apocalypsis,′ meaning "revelation, disclosure," as well as from Greek ‘apokalyptein,′ meaning "uncover, disclose, reveal," being an allusion to a large specimen being so far undiscovered in the north Brazilian deep waters. Distribution: So far known from the type locality.