Kalolophus antillarum ( Reeve, 1842 )

Devries, Thomas J., 2016, Fossil Cenozoic crassatelline bivalves from Peru: New species and generic insights, Acta Palaeontologica Polonica 61 (3), pp. 661-688 : 681-682

publication ID

https://doi.org/ 10.4202/app.00228.2015

persistent identifier

https://treatment.plazi.org/id/AF5F87F5-FFF0-FF9A-FCE6-F966FAD4FE3A

treatment provided by

Felipe

scientific name

Kalolophus antillarum ( Reeve, 1842 )
status

 

Kalolophus antillarum ( Reeve, 1842) View in CoL

Fig. 3A, B View Fig .

1832 Crassatella undulata View in CoL sp. nov.; Sowerby, 1832: 56, not Say 1824, not Lamarck 1801.

1842 Crassatella antillarum View in CoL sp. nov.; Reeve 1842: 44.

1843 Crassatella antillarum View in CoL ; Reeve 1843: vol. 1, pl. 2: 8.

1917 Crassatella digueti View in CoL sp. nov.; Lamy 1917: vol. 62, 2, 7.

1931 Crassatellites antillarum (Reeve) ; Grant and Gale 1931: 271, pl. 13: 7a, b.

1961 Eucrassatella (Hybolophus) diqueti [sic] (Lamy); Olsson 1961: 180, pl. 25: 2.

1964 Eucrassatella (Hybolophus) antillarum (Reeve) View in CoL ; Weisbord 1964: 194, pl. 25: 9, 10.

1979 Eucrassatella (Hybolophus) antillarum (Reeve) View in CoL ; Gibson-Smith and Gibson-Smith 1979: 28.

1984 Eucrassatella antillarum ( Reeve, 1842) View in CoL ; Coan 1984: 160, figs. 12−16.

2012 Eucrassatella antillarum ( Reeve, 1842) View in CoL ; Coan and Valentich-Scott 2012: 398, pl. 130.

See Weisbord (1964) and Coan (1984) for more extensive synonymies.

Holotype: British Museum of Natural History , Zoology, 1953.4.15.10.

Type locality: Isla Margarita, West Indies.

Type horizon: Recent.

Material.— UWBM 101884 About UWBM , Coché , near Margarita Island, Venezuela, on muddy sand at depth of 20−25 m, Recent, L 68.6, H 49.0, T 12.1 ; UWBM 101885 About UWBM , Canal de Adentro Island , Bahia de Panama, western Panama, from depth of 80 m, Recent, L 46.6, H 31.1, T 9.9 .

Emended diagnosis.—Exterior of shell with exclusively irregular commarginal growth lines.

Description.—Shell to 90 mm long, sharply ovate anteriorly, posterior variably produced, beak located two-fifths of distance from anterior L:H ratio 1.4−1.6, T:H ratio 0.2, maximum inflation ventral to beak, nearly as inflated posteriorly as medially. Anteriodorsal profile straight, posteriodorsal profile concave. Anterior margin rounded, ventral margin broadly rounded and slightly constricted posteriorly, posterior margin bluntly truncate. Angular primary posterior ridge diverging 20° from posteriodorsal margin and weakly sulcate on both sides, weaker angular secondary posterior ridge midway between primary posterior ridge and escutcheon. Lunule elongate, sometimes narrow, half the length of anteriodorsal margin. Escutcheon less than half the length of posteriodorsal margin, wider than lunule. Beak and umbo orthogyrate to opisthogyrate. Umbo flattened, with broad undulations, not entirely commarginal and fading posteriorly and anteriorly. Remainder of exterior with irregular commarginal growth lines. Left anterior cardinal tooth narrow, wedge-shaped, inclined anteriorly 50−60°, extending from vmHP to beak, separated entirely from lunule by groove. Left posterior cardinal tooth narrower, wedge-shaped, inclined anteriorly 20−30°. Right anterior pseudocardinal tooth narrow, straight, nearly coincident with lunule margin. Right cardinal tooth straight, wedge-shaped, inclined anteriorly 40°. Right posterior pseudocardinal tooth lamellar, diverging 20° from midpoint of cardinal tooth. Inner ventral margin smooth.

Remarks.— Kalolophus antillarum had become established in the Pacific and Atlantic during the Pliocene ( Grant and Gale 1931; Weisbord 1964; Gibson-Smith and Gibson-Smith 1979). Specimens of the modern sympatric crassatelline in the Pacific Ocean, Hybolophus gibbosus , are more inflated anteriorly, more constricted posteriorly, and their two posterior ridges are more closely spaced, thereby creating a posterior margin that is almost pointed. Specimens of the modern sympatric congener in the Atlantic Ocean, K. speciosus , resemble those of K. antillarum in most respects, but the exterior is entirely covered with regularly spaced and pronounced commarginal ribs ( Fig. 3H View Fig 1 View Fig ).

Stratigraphic and geographic range.—Pliocene–Pleistocene, Gulf of California, Venezuela. Recent, Gulf of California to Guayas, Ecuador, and Venezuela.

Kingdom

Animalia

Phylum

Mollusca

Class

Bivalvia

Order

Carditida

Family

Crassatellidae

Genus

Kalolophus

Loc

Kalolophus antillarum ( Reeve, 1842 )

Devries, Thomas J. 2016
2016
Loc

Eucrassatella antillarum ( Reeve, 1842 )

Coan, E. V. & Valentich-Scott, P. 2012: 398
2012
Loc

Eucrassatella antillarum ( Reeve, 1842 )

Coan, E. V. 1984: 160
1984
Loc

Eucrassatella (Hybolophus) antillarum (Reeve)

Gibson-Smith, J. & Gibson-Smith, W. 1979: 28
1979
Loc

Eucrassatella (Hybolophus) diqueti

Olsson, A. A. 1961: 180
1961
Loc

Crassatellites antillarum (Reeve)

Grant, U. S. & Gale, H. R. 1931: 271
1931
Loc

Crassatella antillarum

Reeve, L. A. 1842: 44
1842
Loc

Crassatella undulata

Sowerby, G. B., I 1832: 56
1832
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