Cavellina cf. rhenana Krömmelbein, 1954

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 : 29-30

Cavellina cf. rhenana Krömmelbein, 1954

(Pl. II: Figs. 7 & 8)

cf. 1954a Cavellina rhenana nov. sp.; Krömmelbein: 250–251, pl. 1, fig. 3.

cf. 1983a Sulcella rhenana (Krömmelbein) ; Milhau: 351, pl. 1, figs. 7–8.

cf. 1985 Cavellina rhenana Krömmelbein ; Coen: 18, pl. 5, figs. 5–8.

cf. 1985 Sulcella rhenana (Krömmelbein) ; Lethiers et al.: 66–67, pl. 9, figs. 6–7. cf. 1988 Sulcella rhenana (Krömmelbein) ; Milhau: 487, pl. 56, fig. 13.

cf. 2009 Cavellina rhenana Krömmelbein ; Casier & Préat: 96, pl. 5, fig. 3.

non 2011b Cavellina cf. rhenana Krömmelbein ; Casier in Casier et al.: 111–113, pl. 2, fig. 13. cf. 2013 Cavellina rhenana Krömmelbein ; Casier & Maillet in Casier et al.: 264, fig. 9B. 2013 Cavellina cf. rhenana Krömmelbein ; Maillet: 85, pl. X, figs. 18–19.

cf. 2013b Cavellina rhenana Krömmelbein ; Maillet et al.: fig. 5K.

cf. 2013c Cavellina rhenana Krömmelbein ; Maillet et al.: figs. 2 A–K.

PLATE II. Ostracods from the type-area of the carbonate Candás Formation. For samples stratigraphic position, see Figure 3. 1 –2 . Evlanella peranensis Maillet n. sp., tecnomorph (1), N2, LV (C. O.F.L.S. 1126); heteromorph (2), N2, slightly oblique dorsal view (C. O.F.L.S. 1127); 3. Poloniella cf. claviformis ( Kummerow, 1953) , I6, RV (C. O.F.L.S. 806); 4–5. Punctoprimitia cf. europaea Weyant, 1967 , adult (4), II1, LV (C. O.F.L.S. 808); juvenile (5), II1, LV (C. O.F.L.S. 809); 6. Cavellina ? wahlensis Coen, 1985, tecnomorph, G1, LV (C. O.F.L.S. 812); 7–8. Cavellina cf. rhenana Krömmelbein, 1954 , heteromorph (7), M2, LV (C. O.F.L.S. 817); tecnomorph (8), M2, LV (C. O.F.L.S. 816); 9–10. Uchtovia refrathensis (Krömmelbein, 1954) , tecnomorph (9), M2, LV (C. O.F.L.S. 827); heteromorph (10), M2, LV (C. O.F.L.S. 1128); 11. Knoxiella ? sp. P1, I6, LV (C. O.F.L.S. 830); 12. Cryptophyllus sp. P1, II1, LV? (C. O.F.L.S. 857); 13. Cryptophyllus sp. P2, O 5, RV? (C. O.F.L.S. 858); 14. Cryptophyllus sp. P3, Q8, internal mould, LV? (C. O.F.L.S. 860); 15. Cryptophyllus sp. P4, M3, LV? (C. O.F.L.S. 838); 16. Roundyella ? sp. indet., I3, LV? (C. O.F.L.S. 786); 17. Cytherellina aff. brassicalis Becker, 1965 , I6, RV (C. O.F.L.S. 872); 18. Cytherellina cf. dubia ( Kummerow, 1953) , G1, RV (C. O.F.L.S. 873); 19. Cytherellina cf. groosae ( Coen, 1985) , B10, RV (C. O.F.L.S. 874); 20. Cytherellina cf. perlonga ( Kummerow, 1953) , B10, RV (C. O.F.L.S. 876); 21. Cytherellina ? sp. P1, A9, RV (C. O.F.L.S. 881); 22. Cytherellina sp. indet., Q8, RV (C. O.F.L.S. 882); 23. Punctomosea ? sp. indet., Q8, RV (C. O.F.L.S. 893); 24. Polyzygia beckmanni beckmanni Krömmelbein, 1954 , V14, RV (C. O.F.L.S. 899); 25. Polyzygia insculpta insculpta Becker, 1964 , II1, RV (C. O.F.L.S. 901); 26–27. Polyzygia neodevonica neodevonica ( Matern, 1929) , adult (26), Q8, RV (C. O.F.L.S. 902); juvenile (27), M2, LV (C. O.F.L.S. 903); 28a, b. Polyzygia symmetrica symmetrica Gürich, 1896 , Q8, RV (a) and dorsal view (b) (C. O.F.L.S. 907).

Material. 3 specimens (3 C).

Description. Medium-sized sub-oval carapace, stocky in tecnomorphs and more elongated in heteromorphs. The larger RV overlaps the LV on whole outline, slightly anteriorly and more clearly ventrally, dorsally and posteriorly. Hmax at 1/3 posterior in tecnomorphs, more anterior in heteromorphs; Lmax slightly ventral; Wmax at 1/3 posterior. Lmax equivalent to about 2 Hmax. Slightly convex dorsal margin, anteriorly oblique (also posteriorly oblique in heteromorphs). Straight to slightly concave ventral margin. Dorsal and ventral margins almost parallel. Regularly convex, well rounded anterior margin. Well rounded posterior margin. Posterior part of the carapace higher than the anterior one. Surface slightly reticulated. Slightly anterior adductorial sulcus, more or less marked.

Discussion. These specimens show a carapace with features close to C. rhenana Krömmelbein, 1954 , except that this one is much more elongate. A marked sexual dimorphism is observed, as usual in cavellinids. Not enough specimens were collected to observe the specific variation as known in C. rhenana ( Maillet et al. 2013c).

Occurrence. Middle Givetian (Candás Fm, mb C), Asturias (Peran-Perlora section).

Figures

FIGURE 3. Stratigraphical distribution of ostracod taxa through the Candás Formation in the Peran-Perlora and Carranques sections. Samples numbers are replaced on a detailed stratigraphical column of the series, on which macro- and microfaunas’ occurrences are indicated.

FIGURE 1. Location maps of the studied area. A. Devonian deposits cropping out in the Cantabrian Zone (adapted from García-Alcalde et al. 2012); B. Simplified geological map of the Luanco-Candás area showing the Naranco, the Candás and the Piñeres Fms (modified from García-López et al. 2002), with location of the Peran-Perlora and Carranques sections; C. Detailed location map of the Peran-Perlora section (adapted from García-López et al. 2002); D. Detailed location map of the Carranques section (adapted from Fernández et al. 1996).

FIGURE 2. Simplified stratigraphical column of the Candás Formation, standard conodont zonation and chronostratigraphy (according to García-Alcalde et al. 1979; García-López 1986 and García-López et al. 2002).