Polyzygia insculpta insculpta Becker, 1964

Maillet, Sebastien, Milhau, Bruno, Vreulx, Michel & Posada, Luis-Carlos Sánchez De, 2016, Givetian ostracods of the Candás Formation (Asturias, North-western Spain): taxonomy, stratigraphy, palaeoecology, relationship to global events and palaeogeographical implications, Zootaxa 4068 (1), pp. 1-78 : 37-38

Polyzygia insculpta insculpta Becker, 1964

(Pl. II; Fig. 25)

1964 Polyzygia ? insculpta nov. sp.; Becker: 53–54, pl. 7, figs. 5–6.

1969 Polyzygia ? insculpta insculpta Becker ; Becker: 259.

1969 Polyzygia insculpta Becker ; Groos: 21, pl. 4, fig. 6.

1970 Polyzygia ? insculpta Becker ; Bultynck: pl. 28, fig. 11.

1971 Polyzygia insculpta insculpta Becker ; Adamczak: 144–145, pl. 1, fig. 1, pl. 4, figs. 1–10. 1972 Polyzygia insculpta insculpta Becker ; Michel: 226–227, pl.10, fig. 1–2. 1982 Polyzygia insculpta insculpta Becker ; Becker & Groos-Uffenorde: 309, pl. 4, fig. 9.? 1989 Polyzygia insculpta ssp. indet. Becker; Becker: 142, pl. 5, fig. 3.

1990 Polyzygia insculpta insculpta Becker ; Casier in Casier & Préat: pl. 1, fig. 32. 1992 Polyzygia insculpta insculpta Becker ; Casier in Casier et al.: 77, pl. 2, fig. 1. 1993 Polyzygia insculpta insculpta Becker ; Kasimi: pl. 17, fig. 14.

1995 Polyzygia insculpta insculpta Becker ; Casier in Casier et al.: 494, pl. 64, fig. 21.? 1995 Polyzygia insculpta insculpta Becker ?; Casier in Casier et al.: 494, pl. 64, fig. 22.? 1997 Polyzygia cf. insculpta insculpta Becker ; Casier et al.: 156, 158, pl. 2, fig. 2. 2001 a Polyzygia insculpta Becker ; Becker: 62–63.

2004 Polyzygia insculpta insculpta Becker; Becker in Becker et al.: 48.

2013 Polyzygia insculpta insculpta Becker ; Maillet: 111, pl. XIV, fig. 22.

Material. 3 specimens (2 V, 1 F).

Diagnosis. Becker (1969, p. 259).

Description. Medium-sized almost equivalve carapace, sub-oval and slender posteriorly in lateral view. Hmax at 2/5 anterior; Lmax slightly ventral; Wmax almost median. Highly arched dorsal margin, strongly oblique both anteriorly and posteriorly from Hmax. Convex ventral margin, becoming more arched at its extremities. Ventral and dorsal margins clearly converging anteriorly and posteriorly. Regularly convex anterior margin, forming an angle of about 140° with the dorsal margin. Regularly convex posterior margin, very highly arched, forming an angle of about 145° with the dorsal margin. Anterior part of the carapace slightly higher than the posterior one. Surface smooth. Longitudinal U-shaped ventral sulcus, extending from the antero-dorsal part to the postero-dorsal part, where it forms a stick towards the internal part of the valves. Two vertical short sulci below the dorsal margin, one median, the other slightly anterior. Carina along the free margins of the carapace.

Discussion. Although rather badly preserved, our specimens exhibit all the features of the species, and particularly the connection between the ventral sulcus and the S3, forming a reversed “U”.

Occurrences. Emsian to Frasnian, Asturias; Givetian, Morocco; Middle Devonian, Ardenne, Eifel and Poland.