Paracypris ovidi Forel, 2020

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 : 48-49

Paracypris ovidi Forel sp. nov.

urn:lsid:zoobank.org:act:7DB2FA3F-A4F7-451A-ACC2-5D3D6199CADD

Fig. 10 H–N

Diagnosis

A small ear-shaped species with conspicuous dorsal angulations and anterior maximum of curvature slightly below mid-height.

Etymology

In reference to the Latin poet Ovid (Publius Ovidius Naso) who died in exile on the Black Sea shore in Tomis, present-day Constanţa ( Romania).

Material examined

Holotype

ROMANIA • 1 complete carapace; Black Sea , Romanian Continental Shelf , borehole 817LV, sample CM31B; Rhaetian, Upper Triassic; MNHN.F. F63268 .

Paratypes

ROMANIA • 1 complete carapace; same collection data as for holotype; Rhaetian, Upper Triassic; MNHN.F. F63271 • 1 complete carapace; same collection data as for holotype; Rhaetian, Upper Triassic; MNHN.F. F63269 .

Other material

ROMANIA • 1 complete carapace; same collection data as for holotype; Rhaetian, Upper Triassic; MNHN.F. F63270 • 1 complete carapace; same collection data as for holotype; Rhaetian, Upper Triassic; MNHN.F. F63364 • 1 complete carapace; same locality as for preceding but sample CM31C; Rhaetian, Upper Triassic; MNHN.F. F63272 • 1 complete carapace; same locality as for preceding but sample CM31A; Rhaetian, Upper Triassic; MNHN.F. F63273 • 11 complete carapaces, 2 broken carapaces; same locality as for preceding but samples CM31A, CM31B and CM31C; Rhaetian, Upper Triassic; MNHN.F. F63358 .

Dimensions

See Fig. 3H .

Description

Carapace small, ear-shaped, tapered posteriorly in lateral view, with H max at antero-dorsal angulation, L max slightly below mid-H and W max at mid-L; LV overlaps RV very thinly along DB, PDB and VB; dorsal margin distinctly tripartite with conspicuous angulations, more uniformly arched in small specimens; ADB, DB and PDB straight, PDB sometimes slightly convex; ADB and DB of similar length (±80% of L max), respectively gently sloping to AB and antero-dorsal angulation; PB short (± 20% of L max), inclined posteriorly with an angle of 45–55°; AB relatively large, with largely rounded AVB and maximum of convexity located slightly below mid-H; PB narrowly rounded, with maximum of curvature slightly above ventral margin; surface smooth; inner structures not visible.

Occurrence

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

Remarks

Paracypris ovidi sp. nov. is closely related to Pseudomacrocypris ? kerabani sp. nov. described below, from which it differs by having dorsal angulations more acute and AB angulation located slightly higher. Paracypris ovidi sp. nov. also displays a normal overlap of LV around RV, which excludes it from Pseudomacrocypris and relates it to Paracypris . Paracypris ovidi sp. nov. also differs from the widespread Jurassic P. redcarensis ( Blake, 1876) (e.g., Harloff & Jäger 1994; Boomer et al. 1998; Ainsworth & Boomer 2001; Honigstein et al. 2014) in being less tapered posteriorly, with a less rounded anterior margin and a less pronounced overlap.

The H/L diagram shown in Fig. 3H documents the occurrence of several ontogenetic stages, the delimitation of which is complicated. The holotype ( Fig. 10H ) and one of the paratypes ( Fig. 10I ) are among the largest specimens recorded. The ontogenetic development of Paracypris ovidi sp. nov. mainly consists in size increase and accentuation of dorsal angulations.

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.

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.