Coccodentalium carduus (Dall, 1889)

Caetano, Carlos Henrique Soares, Scarabino, Victor & Absalão, Ricardo Silva, 2006, Scaphopoda (Mollusca) from the Brazilian continental shelf and upper slope (13 º to 21 ºS) with descriptions of two new species of the genus Cadulus Philippi, 1844, Zootaxa 1267, pp. 1-47 : 18-19

Coccodentalium carduus (Dall, 1889)

Figs. 33–38

+ Dentalium carduus Dall 1889: 423 , pl. 27, fig. 3.

+ Dentalium (Dentalium) carduus : Pilsbry and Sharp 1897: 30, pl. 7, fig. 6; Henderson 1920: 33, pl. 3, figs. 4,5,7.

+ Dentalium (Fissidentalium) floridense Henderson 1920: 64 , pl. 10, figs. 1,2,6,7; Penna­Neme 1974: 113; Scarabino 1975: 184, pl. 59, fig. 902.

+ Dentalium (Coccodentalium) carduus : Emerson 1952: 2.

+ Dentalium (Coccodentalium) carduum : Abbott 1974: 384, fig. 4497.

+ Dentalium (Dentalium) carduum : Turner 1955: 311.

Dentalium (Fissidentalium) amphialum (non Watson 1879): Penna­Neme 1974: 113.

+ Fissidentalium floridense : Scarabino 1985: 199, pl. 72, fig. 1021; Sumida and Pires­Vanin 1997: 781.

+ Fissidentalium carduum : Scarabino 1994: 306, pl. 106, fig. 1509; Steiner and Kabat 2001: 444.

+ Fissidentalium carduus : Steiner and Kabat 2004: 574.

+ Coccodentalium carduum : Steiner 1998: 81.

Type material

Lectotype MCZ 7692 (designated by Henderson, 1920: 33); Paralectotypes USNM 95321, 1 dd, USNM 95322, 1 dd, MCZ 7691, 1 dd.

Diagnosis

Shell long (to 89 mm in length), slightly curved, regularly tapering, yellowish grey. Six primary ribs, secondary ribs present, attaining rapidily similar size of primary ones, transverse riblets present producing a rasp­like surface. Apex with a deep, narrow slit at the convex side. Oral section polygonal, circular to slightly dorsoventrally compressed.

Material examined

Lectotype of Coccodentalium carduus ; IBUFRJ 13786, sta 50, 19 dd; IBUFRJ 14245, sta C13, 3 dd; IBUFRJ 14246, sta A3, 1 lv, 14 dd; IBUFRJ 14306, sta 538, 2 dd; IBUFRJ 14307, sta 19f, 1 dd; IBUFRJ 14308, sta 20, 1 dd.

Distribution

USA: North Carolina, Florida (Henderson 1920; Abbott 1974); Caribbean Sea: Barbados (Henderson 1920); Brazil: Maceió to Rio Grande do Sul (Penna­Neme 1974; Scarabino 1975, 1985, 1994). Living 180 m (Penna­Neme 1974) to 247 m (this study), shells 40 to 1980 m.

Remarks

This species is commonly included in Fissidentalium but the hexagonal apex ( Fig. 34 ) and cancellated sculpture ( Fig. 37 ) clearly place it in Coccodentalium . The six rib scheme is better observed in the apex of young specimens. It could be confused with Paradentalium gouldii or P. americanum that also have a hexagonal apical section, but C. carduus is more tapering and the pattern of the transverse sculpture as well as the apical slit are observed already in early stages of development.

Figures

FIGURES 20 – 38. Genus Antalis and Coccodentalium. (20 – 22) Antalis cerata, IBUFRJ 14253, 27 mm; (23 – 28) Antalis circumcincta, (23) Lectotype BMNH 1887.2. 9.30, 48 mm, (24) Paralectotype BMNH 1887.2. 9.29, 46 mm, (25 – 28) IBUFRJ 14302, 48 mm; (29 – 32) Antalis taphria, IBUFRJ 14254, 16 mm; (33 – 38) Coccodentalium carduus, IBUFRJ 14245, 89 mm. Scale bar = 100 m.