Bairdiacypris multidentata Bolz, 1971

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 : 18-19

Bairdiacypris multidentata Bolz, 1971

Fig. 6 D–E

Bairdiacypris multidentata Bolz, 1971b: 230–231 , pl. 8, figs 98–100.

Bairdiacypris multidentata – Mette et al. 2012: 70.

Material examined

ROMANIA • 1 complete carapace; Black Sea , Romanian Continental Shelf , borehole 817LV, sample CM31A; Rhaetian, Upper Triassic; MNHN.F. F63199 • 1 complete carapace; same locality as for preceding but sample CM31B; Rhaetian, Upper Triassic; MNHN.F. F63200 • 1 broken carapace; same collection data as for preceding; Rhaetian, Upper Triassic; MNHN.F. F63343 .

Dimensions

See Fig. 3A .

Occurrence

Northern Calcareous Alps, Tyrol, Austria, Norian–Rhaetian, Upper Triassic ( Bolz 1971b; Mette et al. 2012); Romanian Continental Shelf, Black Sea, Rhaetian, Upper Triassic (this paper).

Remarks

Bairdiacypris cf. multidentata Bolz, 1971 has been reported from the Eiberg Member, K̂ssen Formation, outcropping at the Eiberg section in the Northern Calcareous Alps ( Mette et al. 2012: 70), but no illustration and no discussion were provided to further discuss this attribution. Bolz (1971b) provided dimensions of complete carapaces, LV and RV: owing to the overlap of LV over RV in B. multidentata , the dimensions of carapaces are here treated as those of LV and all dimensions are plotted in Fig. 3A . Bolz (1971b) illustrated three specimens and stated that the material was not sufficient for an investigation of the ontogeny ( Bolz 1971b: 231). Although the lack of illustrated specimens doesn’t allow a discussion of the morphological changes in B. multidentata through its development, the large dispersion of the H/L scatter plot of all specimens points to a mixture of ontogenetic stages, at least corresponding to five ontogenetic stages (A-4 to adult). The holotype appears to be an immature stage. The only measurable carapace found during the present analysis ( Fig. 6E ) is the smallest known carapace of B. multidentata and corresponds to a very young juvenile in the A-4 stage ( Fig. 3A ).

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.

Fig. 3. Height/length scatter plots of species from borehole 817 Lebăda Vest, drill core CM31, western portion of Black Sea shelf, Rhaetian, Late Triassic. In all diagrams, the dimensions of right (stars) and left (circles) valves of complete carapaces are shown separately and circled or linked. P1 = paratype 1; P2 = paratype 2. A. Bairdiacypris multidentata Bolz, 1971. B. Bairdiacypris argonautaii Forel sp. nov. C. Carinobairdia alpina Kollmann, 1963. D. Ceratobairdia? akhilleusi Forel sp. nov. E. Histriabairdia pontuseuxinusensis Forel gen. et sp. nov. F. Isobythocypris atalantella Forel sp. nov. G. Petasobairdia amazonella Forel sp. nov. H. Paracypris ovidi Forel sp. nov.