Rectonariidae gen. 1

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 : 45

Rectonariidae gen. 1 in Forel et al. 2019

Fig. 10E

Rectonariidae gen. 1 – Forel et al. 2019a: 22, fig. 14c.

Material examined

ROMANIA • 1 RV; Black Sea , Romanian Continental Shelf , borehole 817LV, sample CM31C; Rhaetian, Upper Triassic; MNHN.F. F63265 .

Dimensions

L = 448 µm; H = 302 µm (RV in this paper).

L = 423 µm; H = 262 µm (LV in Forel et al. 2019a).

Occurrence

Kilek section, Tavusçayiri Block, Sorgun Ophiolitic Mélange, southern Turkey, Huğlu Tuffite, Tetraporobrachia haeckeli radiolarian Zone, Julian, Middle Carnian, Upper Triassic ( Forel et al. 2019a); Romanian Continental Shelf, Black Sea, Rhaetian, Upper Triassic (this paper).

Remarks

Forel et al. (2019a) noted the morphological proximity of this taxon to Siciliella Crasquin et al., 2008 from the Lower–Middle Permian of Sicily ( Crasquin et al. 2008), characterized by its subquadrangular outline, the occurrence of a single spine on each valve and LV overlapping RV all around. The unique LV discovered from the Carnian, Late Triassic, of Turkey was kept in open nomenclature because of the impossibility of confirming the nature of the overlap and the occurrence of a spine on each valve ( Forel et al. 2019a). The present RV confirms the presence of a spine on the RV, also positioned in the posteroventral area of the valve, oriented backwards and downwards. However, until a complete carapace allows a description of the relationship between the two valves, it seems unreasonable to artificially extend the stratigraphical range of Siciliella from the Middle–Late Permian up to the Rhaetian, Late Triassic. Nevertheless, although kept in open nomenclature, Rectonariidae gen. 1 in Forel et al. 2019 confirms the occurrence of Rectonariidae during the Late Triassic that was first recorded in the Carnian of Turkey ( Forel et al. 2019a). It further extends the range of Rectonariidae to the Rhaetian.

Figures

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.