Dicrorygma, Poag, 1962

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 : 548

Dicrorygma cf. minuta ( Kaye, 1963)

Fig. 5 D–F

2022 Dicrorygma cf. minuta — Araripe et al., p 7, fig. 5 (1a–b).

Illustrated material. Adult shells, Nº. DGEO-CTG-UFPE-1522 ( Fig. 5D and E ) and Nº. DGEO-CTG-UFPE-1523 ( Fig. 5F ). Illustrated material from the Santo Antonio section (3.10 and 0.3 m, respectively).

Dimension. Nº. DGEO-CTG-UFPE-1522 ( Fig. 5D–E ); L= (LV) 0.321 mm and H= 0.194 mm. Nº. DGEO- CTG-UFPE-1523 ( Fig. 5F ); L= ( RV) 0.315 mm and W= 0.174 mm.

Comparison. It was not possible to compare with reference collection materials. Dicrorygma cf. minuta was compared to illustrations in Babinot et al. (2007); both specimens are very small, with a smooth surface, and a small caudal process in lateral view. It was not possible to compare the dorsal views, so we used confer. We also compared the studied specimens with the illustrations of Dicrorygma ( Orthorygma ?) dimorpha Weiss, 1996; it was observed that this species is longer and larger than D. cf. minuta in dorsal view.

Occurrence and associated fauna. It was recorded in the Santo Antonio section, at the following depths (from base to top): 0.3; 2.1; 2.25; 3.1; 3.4; 3.45; 3.55; 3.65; 5.25; 5.35; 5.45; 5.55 and 5.65 m. Occurring with all species except Dicrorygma ( Orthorygma ?) dimorpha.

Observations. Dicrorygma cf. minuta was compared to Perissocytheridea species found in this study. The main difference is that D. cf. minuta has a smooth surface without any trace of reticulation or punctuation. In addition, it occurs abundantly along the profile, unlike the species belonging to the genus Perissocytheridea .

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

Figures

FIGURE 5. (A–C) Perissocytheridea florisdorsalis sp. nov., nº DGEO-CTG-UFPE-1521, depth 4.05m, (A) right side view, (B) left side view, (C) dorsal view. (D–F) Dicrorygma cf. minuta (Kaye, 1963); (D and E) nº DGEO-CTG-UFPE-1522, depth 3.1m, (D) right side view, (E) left side view; (F) nº DGEO-CTG-UFPE-1523, depth 0.3m, dorsal view. (G–I) Dicrorygma (Orthorygma?) dimorpha Michael Weiss 1996, nº DGEO-CTG-UFPE-1524, depth 5.65m; (G) vista dorsal, (H) right side view, (I) left side view. (J–L) Microceratina retangularis sp. nov., nº DGEO-CTG-UFPE-1525, depth 3.10m; (J) right side view, (K) left side view, (L) dorsal view. (M–O) Alicenula cf. leguminella (Forbes in Lyell 1855), depth 0.3m; (M) dorsal view; (N) left side view; (O) nº DGEO-CTG-UFPE-1526, right side view. (P–R) Theriosynoecum cf. quadrinodosum Krömmelbein & Weber, 1971; nº DGEO-CTG-UFPE-1528, depth 3.1m; (P) dorsal view; (Q) right side view, (R) left side view. The depth reference is from the bottom to the top. Scale bars are equivalent to 100µm.