Acratia sp. 1, Delo, 1930

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 : 15-16

Acratia sp. 1

Fig. 5B

Material examined

ROMANIA • 1 RV; Black Sea , Romanian Continental Shelf , borehole 817LV, sample CM31C; Rhaetian, Upper Triassic; MNHN.F. F63182 .

Dimensions

L = 343 µm; H = 147 µm; H/L = 0.43.

Occurrence

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

Remarks

The small dimensions of this specimen indicate that it may be an immature stage. However, its very rounded anterior margin and downward pointing posterior extremity preclude it from being attributed to any of the co-occurring species of Acratia . Acratia sp. 1 is close to Paracypris sp. 1 in Lord & Lambourne 1991 from the Early Jurassic of Turkey ( Lord & Lambourne 1991) and to Paracypris cf. Paracypris sp. 1 in Lord & Lambourne 1991 in the present paper ( Fig. 10O ). However, the small anteroventral concavity of the present specimen relates it to the genus Acratia . Acratia sp. 1 is also related to A. kollmanni Forel in Forel et al., 2019 from the Carnian, Late Triassic, of Turkey ( Forel et al. 2019a) as shown by its anterior and posterior extremities being located very low, with a uniformly rounded dorsal margin. However, A. kollmanni is shorter and higher and has a more incised antero-ventral concavity.

Figures

Fig. 5 (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. Acratia cf. Acratia sp. A in Bolz 1971, right lateral view of a carapace, sample CM31B (MNHN.F.F63181). B. Acratia sp. 1, external view of a right valve, sample CM31C (MNHN.F.F63182). C. Acratia sp. 2, right lateral view of a carapace, sample CM31A (MNHN.F.F63183). D–G. Bairdia sp. 7 in Mette & Mohtat-Aghai 1999. D. External view of a right valve, sample CM31B (MNHN.F.F63184). E. External view of a right valve, sample CM31A (MNHN.F.F63185). F. External view of a left valve, sample CM31B (MNHN.F.F63186). G. Same specimen, inner view. H–I. Bairdia cf. parva Ainsworth, 1987. H. Right lateral view of a carapace, sample CM31B (MNHN.F.F63187). I. Right lateral view of a carapace, sample CM31B (MNHN.F.F63188). J–K. Bairdia sp. 3. J. Right lateral view of a carapace, sample CM31A (MNHN.F.F63189). K. Right lateral view of a carapace, sample CM31C (MNHN.F.F63190). L–N. Bairdia sp. 4. L. Right lateral view of a carapace, sample CM31C (MNHN.F.F63191). M. Right lateral view of a carapace, sample CM31B (MNHN.F.F63192). N. Same specimen, dorsal view. O–Q. Bairdia sp. 5. O. Right lateral view of a carapace, sample CM31C (MNHN.F.F63193). P. Same specimen, dorsal view. Q. Right lateral view of a carapace, sample CM31B (MNHN.F.F63194). R. Bairdia sp. 6, external view of a left valve, sample CM31C (MNHN.F.F63195). S–T. Bairdia sp. 7. S. Right lateral view of a carapace, sample CM31B (MNHN.F.F63196). T. Same specimen, dorsal view. U. Bairdia sp. 8, right lateral view of a carapace, sample CM31B (MNHN.F.F63197). Scale bars: 100 µm.

Fig. 10 (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–D. Petasobairdia amazonella Forel sp. nov. A. Right lateral view of a carapace, sample CM31A (MNHN.F.F63263). B. Holotype, external view of a left valve, sample CM31C (MNHN.F.F63264). C. Same specimen, inner view, square indicates the area enlarged in D. D. Line drawing of the adductor muscle scar field of the paratype marked in C. E. Rectonariidae gen. 1 in Forel et al. 2019, external view of a right valve, sample CM31C (MNHN.F.F63265). F–G. “Aglaiocypris” sp. F. Right lateral view of a carapace, sample CM31A (MNHN.F.F63266). G. Right lateral view of a carapace, sample CM31C (MNHN.F.F63267). H–N. Paracypris ovidi Forel sp. nov. H. Holotype, right lateral view of a carapace, sample CM31B (MNHN.F.F63268). I. Paratype 2, right lateral view of a carapace, sample CM31B (MNHN.F.F63269). J. Right lateral view of a carapace, sample CM31B (MNHN.F.F63270). K. Paratype 1, right lateral view of a carapace, sample CM31B (MNHN.F.F63271). L. Right lateral view of a carapace, sample CM31C (MNHN.F.F63272). M. Right lateral view of a carapace, sample CM31A (MNHN.F.F63273). N. Same specimen, dorsal view. O. Paracypris cf. Paracypris sp. 1 in Lord & Lambourne 1991, right lateral view of a carapace, sample CM31A (MNHN.F.F63274). P–Q. Paracypris sp. 1. P. Right lateral view of a carapace, sample CM31B (MNHN.F.F63275). Q. Right lateral view of a carapace, sample CM31C (MNHN.F.F63276).R–U. Paracypris sp. 2. R. Right lateral view of a carapace, sample CM31B (MNHN.F.F63277). S. Right lateral view of a carapace, sample CM31C (MNHN.F.F63278). T. Right lateral view of a carapace, sample CM31A (MNHN.F.F63279). U. Right lateral view of a carapace, sample CM31B (MNHN.F.F63280). Scale bars: 100 µm.