Bairdiacypris? sp. 4, Bradfield, 1935

Forel, Marie-Béatrice & Grădinaru, Eugen, 2020, Rhaetian (Late Triassic) ostracods (Crustacea, Ostracoda) from the offshore prolongation of the North Dobrogean Orogen into the Romanian Black Sea shelf, European Journal of Taxonomy 727, pp. 1-83 : 24

Bairdiacypris? sp. 4

Fig. 6 T–U

Material examined

ROMANIA • 1 complete carapace; Black Sea , Romanian Continental Shelf , borehole 817LV, sample CM31B; Rhaetian, Upper Triassic; MNHN.F. F63213 • 1 complete carapace; same locality as for preceding but sample CM31A; Rhaetian, Upper Triassic; MNHN.F. F63214 • 5 complete carapaces; same locality as for preceding but samples CM31A, CM31B and CM31C; Rhaetian, Upper Triassic; MNHN.F. F63345 .

Dimensions

RV: L = 327–809 µm; H = 157–326 µm; H/L = 0.38–0.48.

LV: L = 327–809 µm; H = 167–348 µm; H/L = 0.41–0.51.

Occurrence

Romanian Continental Shelf, Black Sea, Rhaetian, Upper Triassic (this paper).

Remarks

The absence of an antero-ventral offset of the overlap leads to the generic attribution to Bairdiacypris rather than Fabalicypris . However, in the absence of angulations at the dorsal margin, this identification is still tentative. Bairdiacypris ? sp. 4 is closely related to Fabalicypris ? praelonga Donze, 1966 from the Plicatulus Horizon, Hettangian, Early Jurassic, of Le Sartre, Ardèche, France ( Donze 1966). However, Bairdiacypris ? sp. 4 differs by having a more bairdiid AB with a maximum of curvature located higher and the AVB more raised dorsally. It is worth noting that the doubt in the generic attribution of Fabalicypris ? praelonga is related to Donze’s inability to observe the inner structures ( Donze 1966).

Figures

Fig. 6 (opposite page). SEM micrographs of ostracods from borehole 817 Lebăda Vest, drill core CM31, western portion of Black Sea shelf, Rhaetian, Late Triassic. All specimens are housed in the collections of the Muséum national d’histoire naturelle, Paris, France (MNHN). A. Bairdia sp. 8, same specimen as in Fig. 5U, dorsal view. B–C. Bairdia sp. 9. B. Right lateral view of a carapace, sample CM31C (MNHN.F.F63198). C. Same specimen, dorsal view. D–E. Bairdiacypris multidentata Bolz, 1971. D. Right lateral view of a carapace, sample CM31A (MNHN.F.F63199). E. Right lateral view of a carapace, sample CM31B (MNHN.F.F63200). F–O. Bairdiacypris argonautaii Forel sp. nov. F. Paratype 2, right lateral view of a carapace, sample CM31A (MNHN.F.F63201).G. Paratype 1, external view of a right valve, sample CM31B (MNHN.F.F63202). H. Right lateral view of a carapace, sample CM31A (MNHN.F.F63203). I. Right lateral view of a carapace, sample CM31A (MNHN.F.F63204). J. Right lateral view of a carapace, sample CM31B (MNHN.F.F63205). K. Same specimen, dorsal view. L. Right lateral view of a carapace, sample CM31A (MNHN.F.F63206). M. Right lateral view of a carapace, sample CM31A (MNHN.F.F63207). N. Same specimen, dorsal view. O. Right lateral view of a carapace, sample CM31A (MNHN.F.F63208). P. Bairdiacypris sp. in Forel et al. 2018, external view of a right valve, sample CM31A (MNHN.F.F63209). Q. Bairdiacypris sp. 1, external view of a right valve, sample CM31A (MNHN.F.F63210).R. Bairdiacypris sp. 2, external view of a right valve, sample CM31C (MNHN.F.F63211). S. Bairdiacypris sp. 3, external view of a right valve, sample CM31B (MNHN.F.F63212). T–U. Bairdiacypris? sp. 4. T. Right lateral view of a carapace, sample CM31B (MNHN.F.F63213). U. Right lateral view of a carapace, sample CM31A (MNHN.F.F63214). Scale bars: 100 µm.