Perissocytheridea oculusutilis, Tomé & Araripe & Oliveira & Barreto & Prado & Pedrosa & Pereira & Nascimento & Ng, 2022

Tomé, Maria Emilia, Araripe, Rilda, Oliveira, David, Barreto, Alcina, Prado, Ludmila, Pedrosa, Flavia, Pereira, Priscilla, Nascimento, Luiz Ricardo & Ng, Christiano, 2022, Early Cretaceous Ostracoda (Crustacea) from south-centralAraripe Basin, Brazil with descriptions of seven new species, Zootaxa 5159 (4), pp. 535-557 : 545

Perissocytheridea oculusutilis sp. nov.

Fig. 4G–K

2022 Perissocytheridea sp.1 —Araripe et al., p 7, fig. 5 (4a–b).

Etymology: Oculus (lat.) and sutilis (lat.) in reference to the presence of a subtle ocular tubercle.

Holotype: Adult carapace, Nº. DGEO-CTG-UFPE-1519 ( Fig. 4G–K ).

Type locality: Brazil, State of Pernambuco, Municipality of Exu, Santo Antônio section. Coordinates 7° 30’ 06” S and 39° 32’ 36” W .

Type-horizon: Santo Antônio section, Araripe Basin. Calcarenite (F-Sl) corresponds to Romualdo Formation, depth 3.10 m, dated as upper Aptian interval.

Dimension. Nº. DGEO-CTG-UFPE-1519 ( Fig. 4G–K ); L= (LV) 0.358 / ( RV) 0.349 mm, H= 0.194 mm, and W= 0.174 mm.

Diagnosis: Carapace very small, with a subtle ocular tubercle and a ventral projection with a triaxial cap in the posteroventral region.

Description: Carapace very small. Sub-rectangular outline in the lateral view. Ventral margin straight on both valves. Dorsal margin straight and slightly arched, descending to the posterior end. Anterior margin sub-rounded, starting dorsally straight and rounding to ventral margin. Sub-rectangular posterior margin tapering down to the caudal process, which coincides with the greatest length. Greatest height at the anterior portion. The left valve slightly overlaps the right valve in the dorsal margin. In the dorsal view, the ends are sharp. Surface ornamented with primary reticulation and secondary punctuations inside of the reticles. Discrete winged processes in the posteroventral margins, with a smooth triaxial cap, which coincides with the greatest width. It has a very smooth lateral groove. Ocular tubercle evident.

Observations. The main differences between the species described in the present work are the greatest evidence of both secondary ornamentation in punctuation and the ocular tubercle. The triaxial structure on the posteroventral margin, which in the dorsal view appears as two lateral “pins”. It is worth emphasizing the need for a study covering a larger population of the genus Perissocytheridea found in this study.

Occurrence and associated fauna. It was recorded in the Santo Antônio section, at the following depths (from base to top): 0.3; 2.25; 2.65; 3.1; 4.05; 3.55 and 5.45 m. Perissocytheridea oculusutilis sp. nov. does not occur with Dicrorygma ( Orthorygma ?) dimorpha.

Stratigraphic distribution. Brazil, Araripe Basin, Romualdo Formation, upper Aptian.

Figures

FIGURE 4. (A–C) Mantelliana speculum sp. nov., (A) nº DGEO-CTG-UFPE-1514, depth 0.3m, dorsal view; (B) nº DGEO- CTG-UFPE-1515, depth 3.10m, right side view; (C) nº DGEO-CTG-UFPE-1516, depth 2.65m, left side view. (D–F) Paracypris undulareventralis sp. nov., (D) nº DGEO-CTG-UFPE-1517, depth 2.65m, dorsal view; (E and F) nº DGEO-CTG-UFPE-1518, depth 0.3m, (E) right side view; (F) left side view. (G–K) Perissocytheridea oculusutilis sp. nov., nº DGEO-CTG-UFPE-1519, depth 3.10m, (G) dorsal view, (H) right side view, (I) left side view, (J) small eye tubercle and detail of the reticular ornamentation (and punctuated surface between the reticles), (K) detail of the small winged process. (L–O) Perissocytheridea poruslinearis sp. nov., nº DGEO-CTG-UFPE-1520, depth 0.3m; (L) left side view; (M) right side view; (N) dorsal view; (O) detail of the dorsal view with presence of six systematic pores. The depth reference is from the bottom to the top. Scale bars are equivalent to 100µm.