Bairdiocypris symmetrica ( Kummerow, 1953 )

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 : 48

Bairdiocypris symmetrica ( Kummerow, 1953)

(Pl. III: Fig. 15)

1953 Silenites symmetricus nov. sp.; Kummerow: 54, pl. 6, fig. 4.

1960 Silenites symmetricus (Kummerow) ; Sohn: 74.

1965b Bairdiocypris symmetrica (Kummerow) ; Becker: 174, pl. 7 figs. 7–8.

1969 B airdiocypris symmetrica (Kummerow) ; Groos: 62, pl. 10, figs. 4–5.

? 1979 Bairdiocypris sp.; Olempska: 114, pl. 22, fig. 3.

1982 Bairdiocypris cf. symmetrica (Kummerow) ; Milhau: 21, pl. 4, fig. 86.

1985 Bairdiocypris symmetrica (Kummerow) ; Coen: 26, pl. 9, fig. 11.

p 1988 Bairdiocypris cf. rauffi Kroemmelbein, 1952 ; Milhau: 484, pl. 55, fig. 31. 1988 Bairdiocypris cf. symmetrica (Kummerow) ; Milhau: pl. 55, fig. 55.

1991 Bairdiocypris symmetrica (Kummerow) ; Casier in Casier & Préat: text-figs. 2–3, pl. 3, fig. 1. 1992 Bairdiocypris symmetrica (Kummerow) ; Casier in Casier et al.: 88.

1993 Bairdiocypris symmetrica (Kummerow) ; Kasimi: pl. 18, fig. 13.

? 1997 Bairdiocypris symmetrica (Kummerow) ; Casier et al.: 157–158, pl. 3, fig. 14. non 2007 Bairdiocypris sp. A, aff. symmetrica (Kummerow) ; Casier & Préat: 296, pl. 3, fig. 14. 2010b Bairdiocypris symmetrica (Kummerow) ; Casier in Casier et al.: pl. 6, fig. 8. 2011a Bairdiocypris cf. symmetrica (Kummerow) ; Casier in Casier et al.: pl. 3, fig. 5. 2013 Bairdiocypris symmetrica (Kummerow) ; Maillet: 149, pl. XXI, figs. 4–6. non 2013 Bairdiocypris cf. symmetrica (Kummerow) ; Maillet et al.: fig. 5B.

? 2013 Bairdiocypris cf. symmetrica (Kummerow) ; Casier in Casier & Préat: 488, pl. IV, fig. 14.? 2013 Bairdiocypris sp. A, aff. symmetrica (Kummerow) ; Casier in Casier & Préat: 488, pl. IV, fig. 15.

Material. 17 specimens (12 C, 2 V, 3 F).

Diagnosis. Kummerow (1953, p. 54).

Description. Large carapace, sub-trapezoidal in lateral view, biconvex flattened in dorsal view. Overlap of the larger LV over the RV along whole outline, very pronounced dorsally. Marked bow-shaped projection. Hmax median; Lmax at 1/3 ventral; Wmax at 1/3 ventral. Larger LV symmetric in lateral view. Dorsal margin of the smaller RV straight and oblique posteriorly on 1/2 of Lmax in its median part, slightly convex and very oblique anteriorly in its anterior part, slightly convex and very oblique posteriorly in its posterior part. Dorsal margin of larger LV regularly convex. Slightly convex ventral margin. Regularly convex anterior and posterior margins. Posterior end sharper at 1/3 ventral. Anterior part of the carapace higher than the posterior one. Surface smooth.

Discussion. A very common species in Givetian deposits of western Europe.

Occurrences. Lower to Middle Givetian (Trois-Fontaines, Terres d’Haurs, Mont d’Haurs, Névremont Fms, and Fromelennes Fm, Flohimont Members), Ardenne (Flohimont, Cul d’Houille, Jemelle, Resteigne, Couvin, Mont d’Haurs and Aisemont sections), Middle Givetian (Candás Fm, mbs A, B and C), Asturias (Peran-Perlora section); Givetian, Boulonnais; Middle Devonian, Eifel and Ruhr.