Bivalve Seashells of Tropical West America

Transcription

1 Santa Barbara Museum of Natural History Monographs Number 6 Studies in Biodiversity Number 4 Bivalve Seashells of Tropical West America Marine Bivalve Mollusks from Baja California to Northern Perú Part 1 Eugene V. Coan and Paul Valentich-Scott Digital Imaging by Patricia S. Sadeghian SANTA BARBARA MUSEUM OF NATURAL HISTORY 29 Fe b r u a r y 2012

2 Bivalve Seashells of Tropical West America Marine Bivalve Mollusks from Baja California to Northern Peru Eugene V. Coan and Paul Valentich Scott Santa Barbara Museum of Natural History Monographs Number 6 Studies in Biodiversity Number Santa Barbara Museum of Natural History 2559 Puesta del Sol Road Santa Barbara, California USA Library of Congress Cataloging-in-Publication Data Coan, Eugene V. Bivalve seashells of tropical west America : marine bivalve mollusks from Baja California to northern Peru / Eugene V. Coan and Paul Valentich-Scott ; digital imaging by Patricia S. Sadeghian. -- 1st ed. p. cm. -- (Santa Barbara Museum of Natural History monographs number 6 studies in biodiversity ; no. 4) Includes bibliographical references and index. ISBN ((hardcover) : alk. paper) 1. Bivalves--Pacific coast (America)--Classification. 2. Bivalves- -Pacific coast (America)--Identification. 3. Bivalves--Pacific coast (America)--Pictorial works. 4. Bivalves--Tropics-- Classification. 5. Bivalves--Tropics--Identification. 6. Bivalves--Tropics--Pictorial works. I. Valentich Scott, Paul. II. Title. QL430.6.C ' dc ISBN (13) First Edition All rights reserved. This book may not be reproduced in whole or in part for any purpose whatever, without written permission from the publisher (Santa Barbara Museum of Natural History) and the authors. Cover photography by Patricia S. Sadeghian. Digital imaging by Patricia S. Sadeghian and Paul Valentich-Scott. File photos courtesy of Santa Barbara Museum of Natural History. Cover design by Marie G. Murphy and Paul Valentich-Scott. Book design by Marie G. Murphy. Layout by Adrianne Calbreath, Sarah Gwinn, and Paul Valentich-Scott. Printed and bound in China by Everbest Printing Company through FCI Print Group.

3 Order VENERIDA Order Venerida J. E. Gray, 1854 Literature: Matsukuma (2000c). Superfamily CARDIOIDEA Superfamily Cardioidea Lamarck, 1809 Family CARDIIDAE Family Cardiidae Lamarck, 1809 Shell aragonitic, with outer fibrous prismatic, crossed-lamellar middle, and complex crossed-lamellar inner layers; ovoid to rounded, equivalve, inflated, frequently higher than wide; sculpture of radial ribs, sometimes spinose or frilled; sculpture absent in a few; periostracum thin, adherent; umbones prominent; hinge plate wide, with two conical, hooked cardinal teeth in each valve; cardinal teeth cruciform when valves interlocked; left valve with one anterior and one posterior lateral tooth; right valve with one anterior and one or two posterior lateral teeth; ligament short, external, opisthodetic, in groove; dimyarian, with subequal adductor muscles, to monomyarian in the Tridacninae; mantle lobes with wide pedal opening, usually with small area of fusion setting off inhalant and exhalant apertures; small siphons sometimes present; foot long, geniculate; ctenidia synaptorhabdic, plicate, heterorhabdic; labial palps small, narrow; alimentary canal with type 5 stomach; ducts to digestive diverticula numerous, in right and left clusters; style sac joined to mid-gut; intestine passing through ventricle of heart. Family Cardiidae 407

4 Species Characteristics of the Family Cardiidae Taxa Shell shape Radial ribs Posterior / Anterior ends External color Acrosterigma pristipleura 31-41, flat centrally posterior rib tops with nodes white to yellow, with red-brown blotches Dallocardia senticosum 32-40, covered by short spathate scales scales most prominent on ends white, with red and purple blotches Trachycardium consors 30-34, covered by horseshoe-shaped imbricate scales posterodorsal radial ribs raised, lamellar buff, pink, to yellow with rusty brown patches or bands Trachycardium procerum 22-23, very heavy, covered by weak crossbars (in some) radial ribs more flattened on anterior and posterior ends white, with brown flecks (in some) Trachycardium belcheri 23-26, with sawtoothed crests sawtooth crests most prominent on posterior end white to light yellow, with orange or pink sections Papyridea aspersa 43-50, high, rounded posterior end with strong spines white, with red blotches horseshoe-shaped imbricate scales short spathate spines weak crossbars sawtooth crests 408 Bivalve Seashells of Tropical West America

5 Taxa Shell shape Radial ribs Posterior / Anterior ends External color Papyridea crockeri 43-48, low, rounded posterior end with small spines cream, mottled with rosy red, and yellow zones Papyridea hiulcum 33-40, heavy, trigonal posterior end with moderate spines cream, with orange mottling (especially near beaks) Apiocardia obovale 18-22, crossbars on crests posterior slope with finer, more closely spaced radial ribs white Ctenocardia biangulata 26-28, broad, flat, with weak crossbars posterior end set off by sharp keel yellow to tan, sometimes varigated with brown Ctenocardia planicostata 30-33, with numerous, fine, closely spaced crossbars angle between central and posterior slope sharper than Ctenocardia biangulata cream to brown, with brown blotches Trigoniocardia granifera 16-20, nodose, triangular posterior end with more closely spaced radial ribs white to light tan low, rounded radial ribs heavy, trigonal radial ribs low, flat radial ribs Family Cardiidae 409

6 Species Characteristics of the Family Cardiidae - continued Taxa Shell shape Radial ribs Posterior / Anterior ends External color Laevicardium clarionense 45-55, very low, visible as light and dark color patterns not demarcated cream, mottled with red-brown Laevicardium elatum 45-48, low, smooth, widely spaced not demarcated yellow to brown Laevicardium substriatum 31-47, very low, closely spaced, usually only visible on internal ventral margin not demarcated pale yellow to gray Lophocardium annettae > 55, absent anteriorly, stronger posteriorly posterior end truncate pink to red Lophocardium cumingii > 70, very fine; absent anteriorly, low posteriorly posterior end produced, sharply rounded pink to red Microcardium panamense 51-60,central and anterior ribs rounded, with serrate sides posterior end evenly rounded white Microcardium pazianum 50-75, central and anterior ribs narrow, with pits posterior end truncate white, pink dorsally 410 Bivalve Seashells of Tropical West America

7 A family of large, attractive shells, commonly called cockles, containing at least 20 genera with approximately 265 species, predominantly superficial infauna of shallow seas. Three of the five subfamilies are present in the tropical eastern Pacific, with the Cardiinae and Tridacninae not occurring in this province. Hertlein & Strong (1947: ) reported having dredged a single specimen of the western Atlantic Dinocardium robustum (Lightfoot, 1786) from Bahía Santa Inés, Baja California, presumed to have been brought there through human agency. We appreciate the advice of Jan Johan ter Poorten on this family Morphology and Biology: Ansell (1967a), V. C. Barber & Wright (1969), P. F. Berry & Playford (1997), Breum (1970), Creek (1960), Drost (1889), Feder (1967), M. A. Farmer et al. (2001), Grobben (1898), Isaji et al. (2001), Johnstone (1899, 1900), Kingston (1974), Kirkendale (2004), Kishinouye (1894), B. Morton (1970a), Nakazima (1964a), J. H. Norton et al. (1992), Popov (1970, 1974, 1977, 1980b), Purchon (1939a), Savazzi (1983, 1985b), Simkiss (1960), Stasek (1962a), Trueman et al. (1966a, b), Vidal (2001), Wernstedt (1942), Whyte (1975), Yonge (1980b), Zugmayer (1904). Systematics: Broderip (1833b), Clench & Smith (1944), Dall (1901a), Fischer-Piette (1977), Hylleberg (2004a-c, 2009a, b), Jelnes et al. (1971), Kafanov & Popov (1977), Keen (1937a, 1951a, b, 1954b, 1969h, 1980), Kirkendale (2009), Küster & Römer ( ), Lamy ( ), Marwick (1944), R. A. McLean (1939), Poorten (2009), Reeve ( ), Römer (1868), Rosewater (1965), J. A. Schneider (1992, 1995, 1998, 2002), J. A. Schneider & Carter (2001), L. C. Smith (1945), G. B. Sowerby I (1833f), G. B. Sowerby II ( , 1841), Spengler (1799), Tryon (1872b), Vidal (1999), Vidal & Kirkendale (2007), Vokes (1977, 1989), Voskuil & Onverwagt (1989), B. R. Wilson & Stevenson (1977), Xu (1964, 2004d). Subfamily Trachycardiinae Stewart, 1930 Mostly asymmetrical or inequilateral; ribs asymmetrical in cross-section, well developed over entire surface; spines or other sculpture on ribs stronger on posterior rib edges; posterior margin notched; hinge short, less than half shell length; hinge plate wide; cardinal teeth unequal; posterior cardinal in left valve slender. Genus Acrosterigma Dall, 1900 Type species (OD): Cardium dalli Heilprin, Pliocene, Florida. Shell higher than long; ribs variable, sometimes low and weak, ornamented on their tops; posterior quarter contrasting with rest of surface, with tubercular or elongate scales on ridge tops; anterior part of shell with transverse ridges, never horseshoe-like scales; cardinals in right valve separated or touching at their bases, without dorsal saddle. The genus is known from the Oligocene. Group of Acrosterigma dalli, s.s. (Vidal, 1999) Acrosterigma pristipleura (Dall, 1901) Plate 135 Cardium maculosum G. B. Sowerby I, 1833f: 85, non W. Wood, 1815; C. maculatum G. B. Sowerby II, 1840: 4, non Gmelin, 1791: 3255, nom. nov. pro C. maculosum G. B. Sowerby I, non W. Wood; C. (Trachycardium) pristipleura Dall, 1901a: 389, nom. nov. pro C. maculosum G. B. Sowerby I, non W. Wood, and C. maculatum Reeve, non Gmelin; C. hornelli Tomlin, 1928: 194, nom. nov. pro C. maculatum G. B. Sowerby II, non Gmelin, unnecessary additional replacement name. Shell much higher than long; with ribs; ribs on anterior end with low crossbars; central slope with flat ribs; interspaces deep, narrow; posterior-most end with nodes on rib tops; exterior white to yellowish, with reddish-brown to purple bands and blotches; interior white. Length to 61 mm, height to 81 mm [CAS]. In the Golfo de California as far north as Isla Coronados, Baja California (26.1 N) [McClincy Collection], and from the Islas Tres Marías, Jalisco [SBMNH], México, to Punta Montañita, Guayas, Ecuador (1.8 S) [UMML]; Islas Revillagigedo, México [LACM, KLK]; intertidal zone to 80 m [Vidal, 1999; SBMNH]. Family Cardiidae 411

8 Acrosterigma pristipleura Dallocardia senticosum (syntype) Trachycardium consors (syntype) Plate 135. Family Cardiidae. Acrosterigma pristipleura, Ecuador, length 46 mm; Dallocardia senticosum (syntype), Ecuador, length 47 mm; Trachycardium consors (syntype), Ecuador, length 60 mm. See appendix for further specimen data. 412 Bivalve Seashells of Tropical West America

9 This species differs from the western Atlantic A. magnum (Linnaeus, 1758) in having flatter ribs and narrower interspaces. It differs from the Pliocene type species of the genus in being smaller and in lacking an internal radial strengthening rib. Literature: Fischer-Piette (1977: 67), Hertlein & Strong (1947: 147), Hylleberg (2004b: , ; 2004c: ), Keen (1971: 153), Olsson (1961: 248), Tomlin (1931), Vidal (1999: ), Voskuil & Onverwagt (1991: 67-68). Genus Dallocardia Stewart, 1930 Type species (OD): Cardium quadragenarium Conrad, Recent, northeastern Pacific. With spathate spines, stronger on ends, weaker medially; spines on anterior side of ribs on anterior end and on posterior side of ribs from central slope to posterior end. A single specimen of Dallocardia quadragenarium was obtained from shrimp fishermen in Guaymas, Sonora, México [SBMNH]. This may represent material obtained from the outer coast of Baja California, or may be a new distributional record for this species. The genus is known as early as the Oligocene. Dallocardia senticosum (G. B. Sowerby I, 1833) Plate 135 Cardium senticosum G. B. Sowerby I, 1833f: 84; C. rastrum Reeve, 1845: pl. 16. Shell length and height nearly equal; with ribs with short, spathate scales, most prominent on ends and ventrally; exterior white, with reddish or purple blotches; interior white, often with a purple flush. Length to 57 mm, height to 60 mm [CAS, UMML]. Near head of the Golfo de California, at Puerto Peñasco, Sonora, México (31.3 N) [SBMNH], to Bayovar, Piura, Perú (5.9 S) [CAS, UMML]; intertidal zone to 90 m [SBMNH]. Cardium radula Broderip & G. B. Sowerby I, 1829 (p. 366) was described from an unknown locality, never figured, and lacks known type material. It is possible that it might be an older name for D. senticosum (Poorten, personal communication, November 2009), but the present name would be maintained under ICZN Code Art The northeastern Pacific type species of the genus, D. quadragenarium (Conrad, 1837), has more ribs and is less brightly colored. The western Atlantic Dallocardia muricatum (Linnaeus, 1758) is higher, more oblique, and has more ribs. Literature: Fischer-Piette (1977: 54-55, in part; figures are of D. quadragenarium), Gemmell et al. (1987: 38-39), Hertlein & Strong (1947: ), Hylleberg (2004c: 732, ), Keen (1971: 153), E. J. Moore (2002b: 10), Olsson (1961: ), Voskuil & Onverwagt (1991b: 117). Genus Trachycardium Mörch, 1853 Type species (SD Martens, 1870): Cardium isocardia Linnaeus, Recent, western Atlantic. Shell higher than long; ribs high and strong, ornamented on their posterior flanks; posterior quarter not or only weakly contrasting with rest of shell; on median part of shell, ribs with scales to lamellae on their posterior flanks, top margins never serrate; anterior rib flanks with horseshoe-like scales, never transverse ridges; cardinals in right valve connected by a high dorsal saddle. Literature: Vidal (1999), Voskuil & Onverwagt (1991a). Subgenus Trachycardium, s.s. With imbricating scales on all ribs. Family Cardiidae 413

10 Trachycardium (Trachycardium) consors (G. B. Sowerby I, 1833) Plate 135 Cardium consors G. B. Sowerby I, 1833f: 85; Cardium (Trachycardium) consors laxum Dall, 1901a: 389. Shell of large specimens much higher than long, but small specimens subequilateral; with radial ribs covered by imbricate scales; scales low, horseshoe-shaped anteroventrally, raised, lamellar posterodorsally; buff, pink, to yellow, with rusty brown patches or bands, darker posteriorly. Length to 68 mm, height to 84 mm [CAS]. Near head of the Golfo de California at Bahía Adair, Sonora, México (31.5 N) [SBMNH], to Salinas, Guayas, Ecuador (2.2 S) [UMML]; Islas Galápagos, Ecuador [C. P. Hickman & Finet, 1999]; intertidal zone to 90 m [Keen, 1971; SBMNH]. Trachycardium consors differs from the western Atlantic type species of the genus T. isocardia in having more closely set sculpture, a broader hinge plate, and a thicker shell. Literature: Fischer-Piette (1977: 48), Hertlein & Strong (1947: 147), Hylleberg (2004b: , 595), Keen (1971: 153), Olsson (1961: ), Poutiers (1995: 122). Subgenus Mexicardia Stewart, 1930 Type species (OD): Cardium procerum G. B. Sowerby I, Recent, tropical eastern Pacific. Ribs with fine nodes, especially visible on dorsal margin. Trachycardium (Mexicardia) procerum (G. B. Sowerby I, 1833) Plate 136 Cardium procerum G. B. Sowerby I, 1833f: 83; C. panamense G. B. Sowerby I, 1833f: 85; C. laticostatum G. B. Sowerby I, 1833f: 85 (first reviser: Olsson, 1961: 247); C. subelongatus Valenciennes, 1846: pl. 17; Trigoniocardia eudoxia Dall, 1916b: 31, nom. nud.; 1916c: 412; Cardium dulcinea Dall, 1916c: 412; C. rotundatum P. P. Carpenter, 1857b: 247, 307, nom. nud., 1857c: 531, non Dujardin, 1837; C. parvulum Li, 1930: 529, non Dunker, Shell height greater than length; with very heavy radial ribs, overlain by weak crossbars on rib tops on small specimens; white with rusty brown flecks in some; periostracum thin, tan to medium brown. Length to 102 mm; height to 117 mm [FMNH]. Laguna Ojo de Liebre, Pacific coast of Baja California (27.8 N) [SBMNH], into the Golfo de California as far north as near its head at Puerto Peñasco, Sonora (31.3 N) [SBMNN], México, to Bahía de la Independencia, Ica, Perú (14.2 S) [Olsson, 1961]; intertidal zone to 26 m [SBMNH; Hertlein & Strong, 1947]. Also in the Pleistocene of California, México, and Panamá, and the Pliocene of Ecuador. Keen (1971) recognized two species in this subgenus, T. procerum and T. pamanense, with the latter characteristic of the northern end of the Panamic Province, rather than of Panamá. We have observed material from the Pacific coast of Baja California with broad, low, flat radial ribs. Most specimens from the Golfo de California have sharp, triangular radial ribs medially, whereas those from Panamá have low, rounded radial ribs. However, efforts to separate these forms were consistently unsuccessful. Additional statistical, morphologic or molecular studies will be needed to definitively solve this long-standing problem. Olsson (1961) acted as the first reviser in picking one of the two simultaneously published names. Literature: Fischer-Piette (1977: 36-37), Gemmell et al. (1987: 39), M. J. Gosselin et al. (2006), Hertlein & Grant (1972: 260), Hertlein & Strong (1947: ), Hylleberg (2004b: 478, 503, 593; 2004c: , , 712, 743, 784), Keen (1971: 155), Olsson (1961: ), Poutiers (1995: ). 414 Bivalve Seashells of Tropical West America

11 Subgenus Phlogocardia Stewart, 1930 Type species (OD): Cardium belcheri Broderip & G. B. Sowerby I, Recent, tropical eastern Pacific. Rib crests with a vertical frill formed by coalesced scales. This subgenus is known as early as the Miocene. Trachycardium (Phlogocardia) belcheri (Broderip & G. B. Sowerby I, 1829) Plate 136 Cardium belcheri Broderip & G. B. Sowerby I, 1829: 366. Shell slightly higher than long; with radial ribs with saw-toothed crests; exterior white to light yellow, with orange or pink sections; interior white. Height to 54 mm, length to 44 mm [CAS]. Isla Cedros, Baja California [Keen, 1971], into the Golfo de California as far north as Bahía Santa Inés, Baja California (27.0 N) [CAS], and Guaymas, Sonora (27.9 N) [CAS], México, to Caleta la Cruz, Tumbes, Perú (3.6 S) [SBMNH, LACM]; m [SBMNH]. Trachycardium (Phlogocardia) stiriatum (Brown & Pilsbry, 1911) from the Miocene of Costa Rica and Panamá is presumably ancestral to this species. It has more prominent, oblique rib sculpture than T. (P.) belcheri. Literature: Fischer-Piette (1977: 49), Hertlein & Strong (1947: 140; 1955: 186), Hylleberg (2004b: ), Keen (1971: 155), Olsson (1961: 246). Genus Papyridea Swainson, 1840 Type species (SD Gray, 1847): Cardium soleniforme Bruguière, 1789, of W. Wood, 1815; = Cardium latum Born, Recent, western Atlantic. Shell longer than high, longer posteriorly, oval, gaping at ends; ribs generally spinose, with spines on posterior slopes of ridges; hinge short. Literature: Kafanov (1997, 2001), Watters (2002). Papyridea aspersa (G. B. Sowerby I, 1833) Plate 136 Cardium aspersum G. B. Sowerby I, 1833f: 85; Papyridea bullata californica Verrill, 1870: 225. Shell longer than high, moderately inflated; with high, rounded radial ribs; spines on posterior end strong; exterior cream, mottled with reddish brown; interior white, with red blotches; anterior lateral tooth moderately distant from cardinal teeth; posterior gape wide. Length to 64 mm, height to 52 mm [UMML]. Isla Cedros, Baja California Sur (27.9 N) [CAS, LACM], into and throughout the Golfo de California to near its head at Bahía la Choya, Sonora (31.4 N) [LACM, SBMNH], México, to Santa Elena, Guayas, Ecuador (2.2 S) [Olsson, 1961]; Isla del Coco, Costa Rica [KLK]; Islas Galápagos, Ecuador [C. P. Hickman & Finet, 1999: 26]; intertidal zone to 160 m [SBMNH]. Papyridea aspersa has been treated as a subspecies of one or the other of what prove to be two western Atlantic species, P. lata or P. soleniformis, or under the names P. spinosum (Meuschen, 1787) [non-binomial] and P. bullatum (Linnaeus, 1758) [nom. dub.], which have been treated as senior synonyms of these taxa. Papyridea aspersa is closest to P. lata (Born, 1778), which differs in being longer posteriorly. Literature: Fischer-Piette (1977: 72), Gemmell et al. (1987: 39), Hertlein & Strong (1947: 139), Hylleberg (2004b: 417, ), Kafanov (1997: 3), Keen (1971: 155), Olsson (1961: , as a subspecies of P. soleniformis). Family Cardiidae 415

12 Trachycardium procerum Trachycardium belcheri Papyridea aspersa Plate 136. Family Cardiidae. Trachycardium procerum, (right valve) Panamá, length 58 mm, (left valve) México, length 54 mm; Trachycardium belcheri, Perú, length 40 mm; Papyridea aspersa, México, length 57 mm. See appendix for further specimen data. 416 Bivalve Seashells of Tropical West America

13 Papyridea crockeri (Strong & Hertlein, 1937) Plate 137 Cardium (Papyridea) crockeri Strong & Hertlein, 1937: 161. Shell only slightly longer than high, very inflated; with low, rounded radial ribs; spines on posterior end small; exterior cream, mottled with rosy red and zones of yellow; interior white with reddish mottling; anterior lateral tooth very distant from cardinal teeth; posterior gape narrow. Length to 60 mm, height to 55 mm [SBMNH]. In the Golfo de California as far north as Isla Danzante, Baja California (25.8 N) [SBMNH], and Estero Tastiota, Sonora (28.4 N) [SBMNH], México, to Tumbes, Tumbes, Perú (3.5 S) [LACM]; Islas Galápagos, Ecuador [LACM]; m [SBMNH; Keen 1971]. Papyridea crockeri is closest to the western Atlantic P. soleniformis (Bruguière, 1789), differing in being much more ovate. Literature: Fischer-Piette (1977: 72), Hylleberg (2004b: 458), Kafanov (1997: 3), Keen (1971: ), E. J. Moore (2002b: 10-11), Olsson (1961: 249), Strong & Hertlein (1937: ). Papyridea hiulcum (Reeve, 1845) Plate 137 Cardium hiulcum Reeve, 1845: pl. 21; Papyridea mantaensis Olsson, 1961: 250. Shell much longer than high, moderately inflated; with heavy, trigonal radial ribs; spines on posterior end moderately strong; exterior cream with orange mottling, especially near beaks; anterior lateral tooth relatively close to cardinal teeth; posterior gape wide. Length to 70 mm, height to 50 mm [SBMNH]. Isla Danzante, Baja California Sur, México (25.8 N) [SBMNH], to Lobitos, Piura, Perú (4.5 S) [CAS]; intertidal zone to 12 m [SBMNH]. Voskuil & Onverwagt (1991: 120) concluded that Cardium hiulcum Reeve, 1845, is an older name for this species. Kafanov (1997: 3, pl. 2, figs. 2a-c, pl. 2, figs. 1a-c) figured Reeve s material, selected a lectotype, and concluded that C. hiulcum is instead a junior synonym of the western Atlantic P. lata (Born, 1778). In a detailed study of the two western Atlantic taxa, Watters (2002) decided that C. hiulcum is probably an older name for P. mantaensis after all, and J. J. ter Poorten (personal communication, 2011) agrees with this hypothesis. Literature: Bullock (1966: 143), Fischer-Piette (1977: 71), Hylleberg (2004b: 617), Kafanov (1997: 4), Keen (1971: 157), Olsson (1961: 250), Watters (2002: 123). Fraginae Stewart, 1930 The following three genera have been shown to be unrelated to the true fragines, which harbor photosynthetic algae (Kirkendale, 2009). This clade has not yet been named. Genus Apiocardia Olsson, 1961 Type species (OD): Cardium obovale G. B. Sowerby, I, Recent, tropical eastern Pacific. Subovate; ribs with crossbars or nodes. This genus is known from the Miocene. Apiocardia obovale (G. B. Sowerby I, 1833) Plate 137 Cardium obovale G. B. Sowerby I, 1833f: 84; C. ovuloides Reeve, 1845: pl. 22. Shell ovate, much higher than long; rounded radial ribs, with crossbars on their crests; interspaces with commarginal ribs; white exteriorly and interiorly. Length to 14 mm, height to 25 mm [UMML]. The relationship of this species to two taxa named from fossil formations in northwestern South America has yet to be adequately evaluated; these include: Cardium spiekeri Hanna & Israelsky, 1925 (nom. nov. pro Hemicardia affinis Nelson, Family Cardiidae 417

14 Papyridea crockeri Papyridea hiulcum Apiocardia obovale Plate 137. Family Cardiidae. Papyridea crockeri, México, length 59 mm; Papyridea hiulcum, Ecuador, length 70 mm; Apiocardia obovale, México, length 12 mm. See appendix for further specimen data. 418 Bivalve Seashells of Tropical West America

15 1870, non Cardium affine Münster, 1835), from the Upper Miocene of Perú and the Pliocene of Ecuador; and Cardium (Trigoniocardia) cabopasadum Pilsbry & Olsson, 1941, from the Pliocene of Ecuador. Bahía Magdalena, Pacific coast of Baja California Sur (24.6 N) [Keen, 1971], into the Golfo de California as far north as between Rancho El Tule and Rancho Palmilla, Baja California Sur (23.0 N) [LACM], and Mazatlán, Sinaloa [SBMNH], México, to Máncora, Piura, Perú (4.1 S) [UMML]; Isla del Coco, Costa Rica [LACM]; intertidal zone to 100 m [SBMNH]. Literature: Fischer-Piette (1977: ), Hertlein & Strong (1947: 144; 1955: 187), Hylleberg (2004c: 661, )), Keen (1971: ), Olsson (1961: 253), Schneider (1998: , anatomy). Genus Ctenocardia H. Adams & A. Adams, 1857 Ctenocardia H. Adams & A. Adams, Type species (SD Dall, 1900): Cardium hystrix Reeve, 1844, non [Lightfoot], 1786, = Fragum (Ctenocardia) symbolicum Iredale, 1929, nom. nov. Recent, Indo- Pacific. Americardia Stewart, Type species (OD): Cardium medium Linnaeus, Recent, western Atlantic. Shell small to medium in size, subquadrate to obliquely trigonal, with medioposterior angulation and truncate posterior margin; radial ribs of tubular spines or lamellae; interstices in imbricating scales; lunule present; right valve with unequal cardinal teeth joined by dorsal saddle and second posterior lateral tooth, which is sometimes poorly developed. This genus is known from the Oligocene. Ctenocardia biangulata (Broderip & G. B. Sowerby I, 1829) Plate 138 Cardium biangulatum Broderip & G. B. Sowerby I, 1829: 367; C. magnificum P. P. Carpenter, 1857b: 187, ex Deshayes ms, as a synonym of C. biangulatum. Shell trigonal-subquadrate; height approximately equal to length; broad, flat radial ribs, with weak, widely spaced crossbars; interspaces with fine commarginal striae; exterior yellowish, generally variegated with brown, sometimes white or tan without markings; interior often maculated with purple or red. Length and height to 42 mm [LACM]. Santa Cruz Island, California, USA (34.0 N) [LACM], in the Golfo de California, as far north as near its head at Bahía Adair, Sonora, México (31.4 N) [LACM], to Salinas, Guayas, Ecuador (2.2 S) [LACM, UMML]; intertidal zone to 200 m [SBMNH]. The species is recorded as early as the Pliocene of Baja California. Cardium modestum Conrad, 1855, non R. A. Philippi, 1845, non A. Adams & Reeve, 1850, was given as a synonym of this species by F. R. Bernard (1983: 38), and this was followed by Coan et al. (2000), but Conrad s species is an unrelated Eocene fossil taxon that was renamed Cardium blakeanum Dall, 1909, and is probably instead a synonym of Schedocardia breweri (Gabb, 1864). The western Atlantic Ctenocardia media (Linnaeus, 1758) has more numerous, narrower, rounded radial ribs with narrower interspaces. Literature: Coan et al. (2000: 359), Fischer-Piette (1977: ), Gemmell et al. (1987: 39), Grant & Gale (1931: 312), Hertlein & Strong (1947: 140), J. Hertz (1994a), Hylleberg (2004b: 403, 612), Keen (1971: 157), E. J. Moore (2002b: 12-13), Olsson (1961: 251). Ctenocardia planicostata (G. B. Sowerby I, 1833) Plate 138 Cardium planicostatum G. B. Sowerby I, 1833f: 83; C. (Americardia) guanacastense Hertlein & Strong, 1947: , new species proposed because of supposed homonymy C. planicostatum G. B. Sowerby I, non Sedgwick & Murchison, 1829 ; C. magnificum P. P. Carpenter, ex Deshayes ms, auctt., non C. magnificum P. P. Carpenter, Shell high-trigonal, height much greater than length; radial ribs, with numerous fine, closely spaced crossbars; angle between central and posterior slopes sharper than in C. biangulata; hinge proportionately heavier than in C. biangulata; Family Cardiidae 419

16 Ctenocardia biangulata Ctenocardia planicostata Trigoniocardia granifera Plate 138. Family Cardiidae. Ctenocardia biangulata, México, length 33 mm; Ctenocardia planicostata, Ecuador, length 32 mm; Trigoniocardia granifera, México, length 14 mm. See appendix for further specimen data. 420 Bivalve Seashells of Tropical West America

17 exterior cream to light brown with brown blotches; interior generally white, but purplish in some. Length to 44 mm, height to 56 mm [UMML]. Los Islotes, north of Isla Partida, Baja California Sur (24.6 N) [McClincy Collection], and off the Sinaloa coast (23.1 N) [CAS], México, to El Alto, Piura, Perú (4.3 S) [CAS]; Paita, Piura, Perú (5.1 S) [Keen, 1971]; Isla del Coco, Costa Rica [KLK]; intertidal zone to 24 m [SBMNH; BMNH]. Hertlein & Strong (1947) proposed C. guanacastense as a new species because they believed that Cardium planicostatum G. B. Sowerby I, was preoccupied by Sedgwick & Murchison, 1829, but there is no such earlier taxon. (It was made available in 1835, making it a junior homonym.) Literature: Coan (2002d), Fischer-Piette (1977: 120), Hertlein & Strong (1947: ), Hylleberg (2004b: ; 2004c: ), Keen (1971: 157), E. J. Moore (2002b: 11-12), Olsson (1961: 252). Genus Trigoniocardia Dall, 1900 Type species (OD): Cardium graniferum Broderip & G. B. Sowerby I, Recent, tropical eastern Pacific. Relatively small, with few ribs; interspaces with fine commarginal ribs; radial ribs with beads or nodes, not spines; hinge short, angulate. Trigoniocardia granifera (Broderip & G. B. Sowerby I, 1829) Plate 138 Cardium graniferum Broderip & G. B. Sowerby I, 1829: 367; C. alabastrum P. P. Carpenter, 1857b: 247, nom. nud.; 1857c: 94. Shell subtrigonal, height about equal to length; nodose, triangular ribs, widely spaced on anterior and central slopes; rounded, more closely spaced ribs on posterior slope; interspaces with commarginal ribs; exterior white to light tan; interior white, sometimes with a yellow or orange flush. Length to 18 mm; height to 17 mm [LACM]. Arroyo del Conejo, Pacific coast of Baja California Sur (24.1 N) [LACM], into the Golfo de California to near its head at Bahía de Adair, Sonora (31.5 N) [SBMNH], México, to between Puerto Pizarro and Caleta la Cruz, Tumbes, Perú (3.5 S) [LACM, UMML]; Isla del Coco, Costa Rica [LACM]; Islas Galápagos, Ecuador [LACM]; intertidal zone to 66 m [SBMNH]. The species is known from the Pleistocene of Baja California and Panamá, and the Pliocene of Ecuador. Literature: Fischer-Piette (1977: ), Gemmell et al. (1987: 39), Hertlein & Strong (1947: ; 1955: ), Hylleberg (2004b: 371, 536), Keen (1971: 157), Olsson (1961: ). Subfamily Laevicardiinae Keen, 1951 = Nemocardiinae Savazzi, 1985 Shell higher than long; sculpture of low, narrow radial ribs, sometimes stronger on posterior slope, not hollow within; hinge plate long, arched; cardinal teeth not equal in size; anterior left lateral tooth lamelliform. Literature: J. A. Schneider (1995). Genus Laevicardium Swainson, 1840 Laevicardium Swainson, Type species (SD Stoliczka, 1870): Cardium oblongum Gmelin, Recent, Mediterranean. Liocardium Agassiz, 1846, nom. van. Radial ribs weak, obscure on posterior slope, smooth or rarely nodulose. This genus may be known from as early as the Eocene. The name is derived from the Latin laevis, smooth, and the Greek cardia, heart; the gender is neuter. Literature: E. M. Baker & Merrill (1965), Kafanov & Savitsky (1983), Loosanoff & Davis (1963: ), Penchaszadeh & Salaya (1983), Vidal (2005). Family Cardiidae 421

18 Laevicardium clarionense Laevicardium elatum Laevicardium substriatum Plate 139. Family Cardiidae. Laevicardium clarionense, México, length 32 mm; Laevicardium elatum, México, length 92 mm; Laevicardium substriatum, México, length 21 mm. See appendix for further specimen data. 422 Bivalve Seashells of Tropical West America

19 Laevicardium clarionense Hertlein & Strong, 1947 Plate 139 Laevicardium clarionense Hertlein & Strong, 1947: Shell ovate, very oblique, height greater than length; very low, faint radial ribs, visible on the exterior as light and dark color patterns, and interiorly as ventral crenulations; exterior cream, mottled with reddish brown; interior white with yellow to orange flush; periostracum thin, adherent, highly polished. Length to 41 mm, height to 50 mm [LACM]. Punta Refugio, Isla Ángel de la Guarda, Baja California (29.6 N) [LACM], and Guaymas, Sonora (27.9 N) [SBMNH], México, to San Pablo, Guayas, Ecuador (2.2 S) [UMML]; m [SBMNH; Keen, 1971]. Literature: Fischer-Piette (1977: 23), Hertlein & Strong (1947: ), Hylleberg (2004b: 441), Keen (1971: 160), Olsson (1961: 257). Laevicardium elatum (G. B. Sowerby I, 1833) Plate 139 Cardium elatum G. B. Sowerby I, 1833f: 84; Fulva (Laevifulva) ballieni Vidal, 1994: 112. Shell ovate to trigonal, height greater than length; low, smooth radial ribs; exterior color yellow to brown; interior white; anterior and ventral margins finely crenulate within; posterior margin smooth within; periostracum thick, dehiscent, tan to dark brown, silky; juveniles with commarginal ridges in periostracum. Length to 190 mm. Alamitos Bay, California, USA (33.6 N) [LACM]; established populations occurring from Laguna Ojo de Libre [Scammon s Lagoon], Pacific coast of Baja California Sur (27.8 N) [LACM], throughout the Golfo de California to near its head at Bahía la Choya, Sonora (31.4 N) [SBMNH], to Barra de Navidad, Jalisco, México (19.2 N) [SBMNH]; Panamá (~ 9 N) [Keen, 1971]; intertidal zone to 30 m [SBMNH]. The species is recorded as early as the Pleistocene in southern California. Vidal (1994) added a synonym based on a juvenile specimen mislabeled as having come from Hawaii. Literature: Coan et al. (2000: ), Fischer-Piette (1977: 20), Gemmell et al. (1987: 39), Grant & Gale (1931: 304), Hertlein & Strong (1947: 145), Hylleberg (2004b: 494), Keen (1971: 160), Olsson (1961: 257), Poutiers (1995: 121), Villalejo-Fuerte et al. (1996). Laevicardium substriatum (Conrad, 1837) Plate 139 Cardium substriatum Conrad, 1837: 228; C. elenense G. B. Sowerby II, 1840[?]: 6, fig. 58; 1841: 109; Laevicardium apicinum P. P. Carpenter, 1864c: 313; L. pedernalense Pilsbry & Olsson, 1941: 60. Shell ovate to subtrigonal, height less than length; longer posteriorly; very low, fine radial ribs most evident as crenulations along the ventral margin; commarginal undulations near umbones; exterior color pale yellow or gray, flecked with brown; interior with pink, salmon, or purplish-brown mottling; periostracum thin, tan, shiny. Length to 28 mm [SBMNH]. Mugu Lagoon, California, USA (34.1 N) [LACM], throughout the Golfo de California, to near its head at Bahía Adair, Sonora, México (31.5 N) [SBMNH], to Máncora, Piura, Perú (4.1 S) [UMML]; Islas Galápagos, Ecuador [LACM]; intertidal zone to 160 m [SBMNH], in mud or sand. The species is recorded as early as the Pliocene in Baja California Sur. Literature: Fischer-Piette (1977: 22), Gemmell et al. (1987: 39), Hertlein & Strong (1947: ; 1955: 187), Hylleberg (2004b: , ; 2004c: 690, 790), Keen (1971: 160), Olsson (1961: ). Genus Lophocardium P. Fischer, 1887 Type species (M): Cardium cumingii Broderip, Recent, tropical eastern Pacific. Thin, fragile, inflated, gaping posteriorly; umbones inflated; without anterior lateral teeth. This genus is known as early as the Miocene. Literature: Dall (1889b), Woodring (1982: ). Family Cardiidae 423

20 Lophocardium annettae Lophocardium cumingii Plate 140. Family Cardiidae. Lophocardium annettae, México, length 47 mm; Lophocardium cumingii, México, length 27 mm. See appendix for further specimen data. Lophocardium annettae (Dall, 1889) Plate 140 Cardium (Lophocardium) annettae Dall, 1889b: 13; 1890: 264. Shell ovate-subquadrate, height much less than length; posterior end truncate; anterior slope with irregular, rounded commarginal sculpture, transitioning to central slope of more than 55 low radial ribs overlain by commarginal striae; posterior slope demarcated by a raised lamellar rib, with low radial ribs overlain by lamellar commarginal ribs; exterior pink to red; periostracum thin, dull, tan. Length to 57 mm. East of Isla Cedros, Baja California (28.3 N) [Hertlein & Strong, 1947]; in the Golfo de California as far north as San Felipe, Baja California (31.0 N) [SDNHM], and Punta San Antonio, Sonora (27.9 N) [SBMNH], México, to Puerto Culebra, Guanacaste, Costa Rica (10.6 N) [CAS]; intertidal zone to 200 m [Keen, 1971; SBMNH]. Dall (1889b) reported this species from San Clemente Island, California, but there is no material in the USNM from that area (T. Nickens, personal communication, March 2002). The relationship between this species and the older L. cumingii merits additional investigation. Literature: Dall (1890: , pl. 10, anatomy), Fischer-Piette (1977: 8), Hertlein & Strong (1947: ), Hylleberg (2004b: ), Keen (1971: 158), Olsson (1961: ). 424 Bivalve Seashells of Tropical West America

21 Lophocardium cumingii (Broderip, 1833) Plate 140 Cardium cumingii Broderip, 1833b: 82. Shell ovate-elongate, height much less than length; posterior end produced, sharply rounded; anterior slope with irregular commarginal periostracal striae, transitioning to low radial ribs on central slope overlain by commarginal striae; posterior slope demarcated by a radial rib accentuated by periostracum, and with irregular, wavy radial ribs and only low, irregular commarginal periostracal striae; exterior pink or red, generally darker in color than Lophocardium annettae; periostracum thin on anterior and central slopes, thick and brown on posterior slope of fresh specimens. Length to 51 mm [SBMNH]. In the Golfo de California as far north as Bahía Agua Verde, Baja California Sur (25.5 N) [LACM], and Guasave, Sinaloa (25.6 N) [SBMNH], México, to Punta Utria, Choco, Colombia (6.0 N) [LACM]; m [SBMNH]. Literature: Fischer-Piette (1977: 7-8), Hertlein & Strong (1955: ), Hylleberg (2004b: ), Keen (1971: 158), Olsson (1961: 255), L. C. Smith (1945: 31-32). Genus Microcardium Thiele, 1934 Microcardium Thiele, Type species (SD Keen, 1937): Cardium (Fulvia) peramabile Dall, Recent, western Atlantic. Decussicardium Fischer-Piette, Unavailable, no description (ICZN Code Art. 13.1) or designation of type species (ICZN Code Art. 13.3). Proposed for Cardium gilchristi G. B. Sowerby III, Recent, South Africa. Tobarum Noda, Type species (OD): Frigidocardium (Tobarum) tobaruense Noda, Pliocene, Japan. Shell small; commarginal sculpture on anterior and central slopes between radial ribs and sometimes overriding them as beads; some radial ribs on posterior slope with short spines. In Nemocardium, the central slope is nearly smooth, and there are large crenulations on the inner ventral shell margin. Microcardium is recorded as early as the Miocene. Literature: Keen (1950), Poutiers (1992, 2006). Microcardium panamense (Dall, 1908) Plate 141 Protocardia panamense Dall, 1908b: 415 [not preoccupied by Cardium panamense G. B. Sowerby I, 1833f]; Microcardium williami Fischer-Piette, 1977: 4, unnecessary replacement name. Shell ovate-subtrigonal, height approximately equal to length; posterior end evenly rounded; about radial ribs (up to 63, counting marginal crenulations); radial ribs on anterior and central slopes rounded, with serrate sides, giving a pitted appearance; posterior slope with striae between radial ribs and minute spines between some ribs; shell white; periostracum thin, light brown, dull. Length and height to 18 mm [SBMNH]. Isla Ángel de la Guarda, Baja California (29.5 N)[SBMNH], and Guaymas, Sonora (27.9 N) [SBMNH], México, to Bahía San Juan, Ica, Perú (14.4 S) [LACM]; m [SBMNH]. Microcardium panamense is similar in shape to the western Atlantic type species of the genus, Microcardium peramabilis (Dall, 1881), which has more numerous ribs on the anterior and central slopes, with a single crested radial rib transitioning to the posterior slope. Fischer-Piette (1977) unnecessarily replaced the species name. It was neither a primary homonym, nor did he actually consider it to be a secondary homonym. Literature: Dall (1908: 415), Fischer-Piette (1977: 4), Hylleberg (2004c: , 837), Keen (1971: 158), Olsson (1961: 254). Family Cardiidae 425

22 Microcardium panamense Microcardium pazianum Plate 141. Family Cardiidae. Microcardium panamense, México, length 11 mm; Microcardium pazianum, México, length 19 mm. See appendix for further specimen data. Microcardium pazianum (Dall, 1916) Plate 141 Protocardia paziana Dall, 1916c: 412. Shell ovate-subtrigonal, height less than length; posterior end longer, truncate; about radial ribs (up to 95 counting marginal crenulations); ribs on anterior and central slopes narrow, with pits at intersections with commarginal ribs; posterior slope with striae between radial ribs; some rib interspaces on posterior slope with small spines, which are more numerous than in Microcadium panamense; exterior white, dorsal margin tinged pink; interior white, sometimes with pink radial lines or a reddish flush; periostracum thick, dull to silky. Length to 19 mm, height to 19 mm [SBMNH]. Isla Cedros, Baja California [CAS], into the Golfo de California as far north as Guaymas, Sonora (27.9 N) [SBMNH], México, to Isla la Plata, Manabí, Ecuador (1.3 S) (LACM); Islas Galápagos, Ecuador [LACM]; m [SBMNH]. We have seen single lots from Panamá that show variation in the length of the posterior end, a key feature in distinguishing M. panamense from M. pazianum, so their relationship merits additional investigation. Literature: Fischer-Piette (1977: 5), Hertlein & Strong (1947: 142), Hylleberg (2004c: ), Keen (1971: 158), Olsson (1961: 254). 426 Bivalve Seashells of Tropical West America