Novocrania philippinensis

Novocrania philippinenSiS (Dall, 1920) Stratigraphic range: Recent 1920: Crania philippinensis Dall Proc. U. S. Nat. Mus., 57, p. 272. 1986: Neocrania philippinensis (Dall), Lee & Brunton, Bull. Nat. Hist. Mus. (Geol.), 40 (4), p. 152. 2001: Novocrania philippinensis (Dall), Lee & Brunton, Bull. Nat. Hist. Mus. (Geol.), 57 (1), p. 5. 1921: Crania californica Berry Ann. Mag. Nat. Hist., 8, p. 210–212, pl. 11, figs. 1–3. 1986: Neocrania californica (Berry), Lee & Brunton, Bull. Nat. Hist. Mus. (Geol.), 40 (4), p. 152. 2001: Novocrania californica (Berry), Lee & Brunton, Bull. Nat. Hist. Mus. (Geol.), 57 (1), p. 5. Synonymy. Dall (1920) first named this species Crania philippinensis based on specimens from the Philippines. Berry (1921) named and described a single specimen from Santa Monica, California as Crania californica. Cohen et al. (2014, p. 140) stated the two species are “extremely similar and may refer to the same form” and found that they clustered together in their molecular analyses. The material examined included levels of morphological variation similar to other Novocrania species. Novocrania californica is placed in synonymy under N. philippinensis. All scale bars 2 mm unless indicated otherwise. NMNZ—Te Papa Tongarewa, National Museum of New Zealand, Wellington; OU—Geology Museum, University of Otago, Dunedin, New Zealand. Abbreviations: dvvm —dried ventral valve membrane. ncc —non crystalline calcitic material, rr —radial ribs, tsp —tiny spines. All scale bars 2 mm unless indicated otherwise. NMNZ—Te Papa Tongarewa, National Museum of New Zealand, Wellington; NMV—Museum Victoria, Melbourne, Australia; OU—Geology Museum, University of Otago, Dunedin, New Zealand. Abbreviations: aa —anterior adductor muscle scar; aaq —anterior adductor quick-muscle scar, aas —anterior adductor slowmuscle scar, dpa —dried posterior adductor muscle, dmc —dorsal mantle canals, dvvm —dried ventral valve membrane, ncc — non-crystalline calcitic material, oi —oblique internal muscle scar, pa —posterior adductor muscle scar, sam —small anterior muscle scar, sm —score mark, ss —support structure scar. Stratigraphic range. Novocrania philippinensis is provisionally restricted to Recent as I am unaware of any fossil material. However, the calibrated time-tree (App. Fig. 1; Table 3) gives an age of ~ 9.7 Ma for the (within the N.E. Atlantic clade) split between specimens of N. philippinensis from Taiwan and Vancouver Island, Canada (node G, see below) and the wide Recent geographical range of this species is shown herein (Fig. 5). It seems likely that this species will have a fossil history. Type specimens and type locality. The type material is held in National Museum of Natural History, Smithsonian Institute, Washington DC. (USNM 274128). The type locality is between Masbate and Leyte Islands, Philippines, 11.57°N, 123.68°E (Dall 1920). Material examined. The type specimen was borrowed from the Smithsonian Institute. Recent specimens were examined from Vancouver Island, Taiwan and Japan (Table 8). Images of specimens from Taiwan and Vancouver Island were supplied by Carsten Lüter of the Museum für Naturkunde, Berlin. Localities. Novocrania philippinensis is found in the Philippines (Dall 1920), off the California Coast (Berry 1921), along the coast of British Columbia, Canada, in Barkley Sound, Vancouver Island (Bernard 1972, Austin 1985; La Barbera 1986; Vasquez & Young 1996) and in Dean and Burke Fiords (Tunnicliffe & Wilson 1988), Taiwan (Cohen et al. 2014), and Japan (Cohen et al. 2014; this study). Localities are shown in Figure 5 and includes localities of material examined (Table 8) and published localities (Appendix 6). Description. The specimens vary in outline from sub-oval to sub-quadrate to sub-pentagonal (Fig. 14A–E), the posterior margin is often wide and may be straight or concave. Specimens from Vancouver Island are a mottled black and brown in colour (Fig. 14B, the white patches are epibionts), specimens from off Japan and the type specimen from the Philippines (Fig. 14A, F) are brown. The dorsal valve ornament varies from smooth to hummocky with concentric growth lines (Fig. 14A, B) to having a few to 100+ minute spines or pustules (Fig. 14C, G). The pustules/spines may be randomly scattered, or grow in concentric rings (Fig. 14C) and are up to ~ 300µm long (Fig. 14G). The largest complete specimen examined was 23.7 mm long, 27.5 mm wide and 11.2 mm high, All scale bars 5 mm unless indicated otherwise. OU—Geology Museum, University of Otago, Dunedin, New Zealand; UMUT—Tokyo University Museum, Tokyo, Japan; USNM—National Museum of Natural History, Smithsonian Institution, Washington, USA. Abbreviations: aaq —anterior adductor quick-muscle scar, aas —anterior adductor slow-muscle scar, cmr —concave marginal rim, dmc —dorsal mantle canal, mp —median process, oi —oblique internal muscle scar, pa —posterior adductor muscle scar, rp —raised pedestal, sam —small anterior muscle scar, ss —support structure scar. All scale bars 2 mm. Image A taken by Sarah Long, Natural History Museum, London; image C taken by Jun Nemoto, Tokohu University Museum, Sendai; IGPS—Tokohu University Museum, Sendai, Japan; OU—Geology Museum, University of Otago, Dunedin, New Zealand; ZMB—Museum für Naturkunde, Berlin, Germany. Abbreviations: aa —anterior adductor muscle scar, pa —posterior adductor muscle scar, ro —rostellum; sm —small mound, ss —support structure scar, tu —tubercles, vmc —ventral mantle canals. the dorsal valve was up to 0.45 mm thick and the ventral valve up to 2 mm thick (IGPS 58850 from off Sado Island, Sea of Japan). The posterior adductor muscle scars are sub-oval to irregular in shape, the anterior adductor slow-muscle scars are commonly convex and may be on the valve floor (Fig. 14D, H) or raised on pedestals (Fig. 14E, I–K) and are commonly thinner at the lateral ends than in other Novocrania species. The anterior adductor scars may face ventrally (Fig. 14D, E) or be tilted towards the posterior (Fig. 14J, K). The support structure scars are often placed at the lateral ends of the anterior adductor slow-muscle scars (Fig. 14E, I–K) making the latter scars seem elongated. The support structure scars are often raised and face medially. The small anterior muscle scars attach to a single median process of variable length. The valve surface is densely punctate. The dorsal valve is often deeper than the ventral valve and has a concave marginal rim up to 2 mm wide (Fig. 14E, F, I, J) that is sometimes tuberculate on the inner edge. The dorsal mantle canal main stem often runs closely beside the anterior adductor muscles, thus the mantle canal branches may appear to open from the anterior side of the anterior adductor muscles (Fig. 14E, I). The ventral valve is a densely-punctate shallow bowl with tubercles on the wide convex marginal rims and a calcitic rostellum (Fig. 15A–E). The dorsal valve varies from sub-conical to conical (Fig. 15D, E). The posterior adductor muscle scars are irregular in shape. The rostellum has a rounded tip where the oblique internal muscles attach (but no spike as in N. turbinata). The anterior adductor muscle scars have deep quick-muscle dimples (Fig. 15A–C). The ventral mantle canals may be strongly incised into the valve floor (Fig. 15A). A cutaway 3D image (Fig. 15D) and vertical slice down the midline (Fig. 15E) shows the ventral valve may be very thin around the rostellum. Ecology. In the Barkley Sound area of Vancouver Island, Canada, N. philippinensis is found on the rock walls of the northern fjords and where it occurs it is usually the most abundant organism present with densities of at least 500/m2 (Tunnicliffe & Wilson 1988). It has a depth range of 35–510 m but is most common at less than 200 m and is usually on “sloping rock faces where sediment can accumulate” (Tunnicliffe & Wilson 1988, p. 126). In Japan the known depth range is 43–316 m (Table 8). Dall (1920) reported that the type specimens from the Philippines were collected at 208 m on green mud. La Barbera (1986) noted that in this species the feeding current enters the valves at the anterior and exits laterally; this is the opposite of N. anomala where the currents enter laterally and exit anteriorly (Chuang 1974).

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