Paracypris undulareventralis, 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 : 544

Paracypris undulareventralis sp. nov.

Fig. 4D–F

2022 Paracypris sp. —Araripe et al., p 7, fig. 5 (8a–b).

Etymology: Undulare (lat.), suggested due to the significant concave undulation, and ventralis (lat.) where the undulation is present.

Holotype: Adult shell, Nº. DGEO-CTG-UFPE-1517 ( Fig. 4D ). Illustrated material from the Santo Antônio section 2.65 m.

Paratypes: Adult shell, Nº. DGEO-CTG-UFPE-1518 ( Fig. 4E and F ). Illustrated material from the Santo Antônio section 0.3 m.

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 0.3 m, dated as upper Aptian.

Dimension. Nº. DGEO-CTG-UFPE-1517 ( Fig. 4D ); L= (LV) 0.568 / ( RV) 0.635mm, H= 0.299mm, and W= 0.220mm.

Diagnosis: Carapace smooth, with a pronounced concave sinuosity in the posteroventral region.

Description: Carapace medium, sub-triangular in lateral view. VM with a concave sinuosity in the posteroventral region. Dorsal margin angled in the interior portion that coincides with the greatest height. Rounded anterior and posterior margins, the latter being lower. Greater length in the ventral region, just above the ventral sinuosity. Greater anterodorsal height coinciding with the location of the cardinal angle. LV larger than RV with evident overlaps on the central-ventral margin. In the dorsal view, greatest width in the posterior region. Smooth surface.

Observations. Paracypris undulareventralis sp. nov. was compared with Candonopsis alagoensis Tomé et al. (2014) deposited in the Ivan de Medeiros Tinoco Microfossils Collection. The studied species has a very marked sinuosity in the posteroventral region while C. alagoensis does not.

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; 3.55; 3.65; 5.25; 5.45 and 5.55 m. Paracypris undulareventralis sp. nov. does not occur with Dicrorygma ( Orthorygma ?) dimorpha and Theriosynoecum cf. quadrinodosum .

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.