Mantelliana speculum, 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 : 543-544

Mantelliana speculum sp. nov.

Fig. 4A–C

2022 Mantelliana sp. —Araripe et al., p. 7, fig. 5 (9a–b).

Etymology: Speculum (lat.) due to the symmetry between the front and back ends that are reflected like a mirror.

Holotype: Adult shell, Nº. DGEO-CTG-UFPE-1514 ( Fig. 4A ), Illustrated material from the Santo Antônio section 0.3 m.

Paratypes: Adult shell, Nº. DGEO-CTG-UFPE-1515 ( Fig. 4B ) and Nº. DGEO-CTG-UFPE-1516 ( Fig. 4C ), Illustrated material from the Santo Antônio section 3.1 and 2.65 m respectively.

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) corresponding to the Romualdo Formation, depth 0.30 m, dated as upper Aptian.

Dimension. Nº. DGEO-CTG-UFPE-1514 ( Fig. 4B ); L= (LV) 0.870 / ( RV) 0.976 mm, H= 0.623 and W= 0.443 mm.

Diagnosis: Carapace large, triangular, inflated and perfectly symmetrical between both ends.

Description: Carapace large, triangular outline in lateral view. Ventral margin straight. Dorsal margin with a well-marked median angularity that coincides with the greatest height. Perfectly rounded margin. Maximum length in VM. Greatest height in the median region coinciding with the location of the cardinal angle. LV larger than VR with characteristic overlaps in the ventral, posterodorsal and anterodorsal regions. In dorsal view, greatest width in the median region. Smooth surface.

Observations. Mantelliana speculum sp. nov. was compared with the female specimen of Mantelliana wealdensis (Jones, 1888) described and illustrated by Anderson, (1985). However, the well-marked angle in the dorsal region described by Anderson (1985) is not centralized, thus not dividing the valves into two practically identical parts as in the new species.

Occurrence and associated fauna. It was recorded in the Santo Antonio section, at the following depths (from base to top): 0.3; 2.25; 3.1; 3.55; 3.65; 3.85; 4.05; 5.25; 5.35; 5.55 and 5.65 m. Mantelliana speculum sp. nov. occurs associated with all species of ostracods.

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.