Lobobairdia salinaria Kollmann, 1963

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 : 42

Lobobairdia salinaria Kollmann, 1963

Fig. 9 J–M

Lobobairdia salinaria Kollmann 1963: 169, pl. 6, figs 9–12.

Ptychobairdia ? sp. – Kollmann 1960: 102, pl. 27, figs 5–8.

Lobobairdia salinaria – Bolz 1969: 419, pl. 1, fig. 7–10. — Urlichs 1972: 675, pl. 1, fig. 1. — Mette & Mohtat-Aghai 1999: pl. 5, figs 9–10. — Zorn 2010: 271, pl. 7, figs 1–4.

non Lobobairdia salinaria – Sebe et al. 2013: 358.

Material examined

ROMANIA • 1 RV; Black Sea , Romanian Continental Shelf , borehole 817LV, sample CM31B; Rhaetian, Upper Triassic; MNHN.F. F63252 • 1 LV; same collection data as for preceding; Rhaetian, Upper Triassic; MNHN.F. F63253 • 1 LV; same collection data as for preceding; Rhaetian, Upper Triassic; MNHN.F. F63254 • 1 LV; same locality as for preceding but sample CM31C; Rhaetian, Upper Triassic; MNHN.F. F63255 • 1 broken RV, 5 broken LV; same locality as for preceding but samples CM31A, CM13B and CM31C; Rhaetian, Upper Triassic; MNHN.F. F63355 .

Dimensions

RV: L = 584 µm; H = 373 µm; H/L = 0.64.

LV: L = 615–678 µm; H = 405–454 µm; H/L = 0.66–0.67.

Occurrence

Rhaetian, Late Triassic, Zlambach Formation, Hallstatt, Salzberg, Upper Austria, Austria ( Kollmann 1960, 1963; Bolz 1969; Zorn 2010); Austria, Rhaetian, Upper Triassic ( Urlichs 1972); K̂ssen Formation, Northern Calcareous Alps, Tyrol, Austria, Rhaetian, Upper Triassic ( Mette & Mohtat-Aghai 1999); Romanian Continental Shelf, Black Sea, Rhaetian, Upper Triassic (this paper).

Remarks

The present record is the first known occurrence of Lobobairdia salinaria outside of Austria. This species appears to be typical for the Rhaetian of Western Europe. It is mentioned as part of the Aegean, Lower Anisian, Middle Triassic assemblage of the North Dobrogean Orogen ( Sebe et al. 2013). However, such an early occurrence prescribes extreme care as it would extend the range of this species to more than 40 Ma. Because this specimen was not illustrated, we consider this Middle Triassic occurrence as invalid.

Bolz (1969) plotted the dimensions of 169 specimens of Lobobairdia salinaria and identified five ontogenetic stages, from A-4 to adult. The only complete RV obtained from the present analysis corresponds to an A-1 stage based on the ranges provided by Bolz (1969). Conversely, the three LV correspond to the A-2 stage as defined by Bolz (1969). The largest LV shown in Fig. 9M bears a drill hole, which is described in the discussion chapter.

Figures

Fig. 9 (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. Isobythocypris sp., right lateral view of a carapace, sample CM31C (MNHN.F.F63245). B–I. Isobythocypris atalantella Forel sp. nov. B. Holotype, right lateral view of a carapace, sample CM31B (MNHN.F.F63246). C. Same specimen, ventral view. D. Paratype, right lateral view of a carapace, sample CM31B (MNHN.F.F63247). E. Right lateral view of a carapace, sample CM31B (MNHN.F.F63248). F. Right lateral view of a carapace, sample CM31B (MNHN.F.F63249). G. Right lateral view of a carapace, sample CM31C (MNHN.F.F63250). H. Right lateral view of a carapace, sample CM31B (MNHN.F.F63251). I. Same specimen, dorsal view. J–M. Lobobairdia salinara Kollmann, 1963. J. External view of a right valve, sample CM31B (MNHN.F.F63252).K. External view of a left valve, sample CM31B (MNHN.F.F63253). L. External view of a left valve, sample CM31B (MNHN.F.F63254). M. External view of a left valve, sample CM31C (MNHN.F.F63255). N. Lobobairdia? sp. 1, right lateral view of a carapace, sample CM31B (MNHN.F.F63256). O. Lobobairdia sp. 2, right lateral view of a carapace, sample CM31C (MNHN.F.F63257). P. Mirabairdia sp., external view of a left valve, sample CM31A (MNHN.F.F63258). Q–U. Petasobairdia amazonella Forel sp. nov. Q. Right lateral view of a carapace, sample CM31C (MNHN.F.F63259). R. Right lateral view of a carapace, sample CM31A (MNHN.F.F63260).S. Paratype, right lateral view of a carapace, sample CM31B (MNHN.F.F63261). T. Same specimen, dorsal view. U. Right lateral view of a carapace, sample CM31B (MNHN.F.F63262). Scale bars: 100 µm.