Connexochiton platynomenus Kaas, 1979

Sirenko, Boris, 2021, Composition of the genus Connexochiton Kaas, 1979 (Mollusca: Polyplacophora Ischnochitonidae), Zootaxa 4950 (1), pp. 83-102 : 85-86

Connexochiton platynomenus Kaas, 1979

( Figs. 1 , 15E, G )

Connexochiton platynomenus Kaas 1979: 25 , pl. 5: figs. 1–18; 1991: 93; Ferreira 1980: 59; Kaas & Van Belle 1987: 257, fig. 116, map 37; 1990: 54, fig. 22, map 30; Dell’Angelo & Palazzi 1994: 234, fossil).

Bathychiton biondii Dell’Angelo & Palazzi 1988: 115 , figs. 1–26; Smriglio et al. 1989: 128; Saito & Okutani 1990: 174; Dell’Angelo & Palazzi 1994: 234; Biondi & Di Paco 1996: 19 Dell’Angelo & Smriglio 2001: 91, pl. 27–28, figs. 37–39, and 99, pl. 27, fig. F, fossil.

Types. Holotype (MNHN-IM-2000-6014).

Type locality. Bay of Biscay , 48°37’N 09°52’W, 800–1050 m .

Material examined. Holotype was covered with cristals. Mediterranean Sea , St. Lucia Bank, 400 m. 5 valves ( ZISP 2381 ), identified as Bathychiton biondii by Bruno Dell’Angelo.

Distribution. East Atlantic Ocean: Canary Islands (480–540 m), Bay of Biscay (800–1050 m), Gibraltar Strait (1378 m), Mediterranean Sea (250–400 m), Pleistocene, Calabria, Italy.

Remarks. Good descriptions were given by Kaas (1979) and by Kaas & Van Belle (1990) for C. platynomenus and by Dell’Angelo & Palazzi (1988) and Dell’Angelo & Smriglio (2001) for Bathychiton biondii . I agree with Kaas & Van Belle (1990) who synonymized B. biondii with C. platynomenus .

Connexochiton platynomenus differs from other species of the genus Connexochiton by having one transverse row of large globular spherules and longitudinal ribs on the dorsal scales.

Figures

FIGURE 1. Connexochiton platynomenus, Mediterranean Sea, St. Lucia Bank, 400 m, (ZISP 2381): A. Valve I, dorsal view; B. Valve II, dorsal view; C. Valve II, rostral view; D. Valve II, detail of tegmentum in central area; E. Valve I, detail of tegmentum.

FIGURE 15. Aesthete groups in central area and dorsal scales of species of genus Connexochiton: C. kaasi (ZISP 2379) (A, K); C. solomonicus n. sp. holotype (MNHN-IM-2007-17458) (B, I); C. costatus n. sp. holotype (MNHN-IM-2013-67045) (C, F); C. kermadeci n. sp. holotype (NMNZ M 137527) (D, J); C. platynomenus, (E, G), E- specimen from the Mediterranian Sea (ZISP 2381), G- holotype of Bathychiton biondii, Tuscan Archipelago, Mediterranian Sea, after Dell’Angelo & Smriglio 2001, pl. 28, fig. O; C. crassus, holotype (MNHN-IM-2000-6220), after Kaas 1985, (H). Scale bar 100 µm.