Theriosynoecum cf. quadrinodosum Krömmelbein & Weber, 1971

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 : 552

Theriosynoecum cf. quadrinodosum Krömmelbein & Weber, 1971

Fig. 5P–R

1978a Bisulcocypris quadrinodosa —Silva: 1018–20; est. 1, figs. 9–12

2002 Theriosynoecum quadrinodosum — Coimbra et al., Fig. 4 :5–6.

2020 Theriosynoecum quadrinodosum — Guzmán-González et al., Fig. 5 (b).

2022 Theriosynoecum quadrinodosum — Araripe et al., p 7, fig. 5 (11a–b).

Illustrated material. Juvenile shell, Nº. DGEO-CTG-UFPE-1528. Illustrated material from the Santo Antônio section (3.1 m).

Dimension. Nº. DGEO-CTG-UFPE-1528 ( Fig. 5P–R ); L= (LV) 0.603/ ( RV) 0.688 mm, W= 0.365 mm and H= 0.352 mm.

Comparison. Material compared to Theriosynoecum silvai ( Silva, 1978a) (Nº DGEO-CTG-UFPE-1970 e DGEO-CTG-UFPE-1166), described and deposited by Tomé et al. (2014) in the Ivan de Medeiros Tinoco Microfossils Collection of the Paleontology Laboratory of the Federal University of Pernambuco. It was observed that the specimen found in the present study corresponds to a juvenile specimen and it has nodules in the posterior margin that differentiate it from the species deposited in the mentioned collection.

Occurrence and associated fauna. It was recorded in the Santo Antonio section, just in the depths (from base to top): 0.3 m. T. cf. quadrinodosum is associated with the species of ostracods: P. angulata , P. micropapillosa , D. grandiensis , D. cf. minuta, Mantelliana speculum sp. nov. and Mongolianella aptianensis sp. nov.

Observations. So far four species belonging to the genus Theriosynoecum Branson (1936) have been recorded in the Aptian/Albian: Theriosynoecum silvai ( Silva, 1978a) , Theriosynoecum munizi ( Silva, 1978a) , Theriosynoecum colini Do Carmo et al., 2013 and Theriosynoecum guzzoia Do Carmo et al., 2013 . Regarding the first two, Tomé et al. (2014) placed T. munizi in synonymy as being a young form of T. silvai . The specimen observed in the present manuscript does not resemble the forms found for this interval. However, it corresponds to a young male of Theriosynoecum quadrinodosum , with characteristic nodules in the posterior margin. This species is recorded in interior basins in Northeast Brazil, of Jurassic age ( Silva et al. 1978a; Coimbra et al. 2002; Guzmán-González et al. 2020), so if the range of the T. quadrinodosum is confirmed, it would be recorded as far back as the Aptian. What made the authors leave this species in confer is the fact that they found only a single, unique specimen among all the samples.

Stratigraphic distribution. Brazil, Araripe Basin, Formação, Brejo Santo, Jurassic ( Coimbra et al. 2002). Jatobá Basin, Aliança Formation, Jurassic ( Guzmán-González et al. 2020). 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.

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.