Ostracoda (Arthropoda, Crustacea) from the Riachuelo Formation, Sergipe-Alagoas Basin, Brazil, Upper Aptian-Albian Author Antonietto, Lucas Silveira 4E63F407-03D6-4D06-9318-72FA2A23E014 Laboratory of Micropaleontology, Institute of Geosciences, University of Brasilia, Darcy Ribeiro Campus, CEP 70919 - 970 Brasilia, Distrito Federal, Brazil. & urn: lsid: zoobank. org: author: 4 E 63 F 407 - 03 D 6 - 4 D 06 - 9318 - 72 FA 2 A 23 E 014 & Corresponding author: antoniettols @ gmail. com antoniettols@gmail.com Author Carmo, Dermeval Aparecido do 911A76DB-38C3-482F-A7AC-2D57F0AFF90D Laboratory of Micropaleontology, Institute of Geosciences, University of Brasilia, Darcy Ribeiro Campus, CEP 70919 - 970 Brasilia, Distrito Federal, Brazil. & Email: derme @ unb. br & urn: lsid: zoobank. org: author: 911 A 76 DB- 38 C 3 - 482 F-A 7 AC- 2 D 57 F 0 AFF 90 D derme@unb.br Author Viviers, Marta Claudia B0CACF44-1ED6-49E0-928B-EA7FF769854F Petrobras-CENPES-PDGEO / BPA, Horácio Macedo Avenue, 950, CEP 21940 - 900, Rio de Janeiro, Rio de Janeiro, Brazil. & Email: mcviviers @ oi. com. br & urn: lsid: zoobank. org: author: B 0 CACF 44 - 1 ED 6 - 49 E 0 - 928 B-EA 7 FF 769854 F mcviviers@oi.com.br Author Neto, João Villar Queiroz 5BB35DBF-70E2-450A-A521-6ECE846052F9 Petrobras-CENPES-PDGEO / BPA, Horácio Macedo Avenue, 950, CEP 21940 - 900, Rio de Janeiro, Rio de Janeiro, Brazil. & Email: joaovq @ petrobras. com. br & urn: lsid: zoobank. org: author: 5 BB 35 DBF- 70 E 2 - 450 A-A 521 - 6 ECE 846052 F 9 joaovq@petrobras.com.br Author Hunt, Gene C94AA495-663C-4C5E-9D86-BEF1A32528BD Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, 10 th Street & Constitution Avenue NW, 20560 - 0121 Washington D. C., U. S. A. & Email: hunte @ si. edu & urn: lsid: zoobank. org: author: C 94 AA 495 - 663 C- 4 C 5 E- 9 D 86 - BEF 1 A 32528 BD hunte@si.edu text European Journal of Taxonomy 2016 2016-11-17 244 1 57 journal article 21860 10.5852/ejt.2016.244 3b46d4f3-8a5a-4d63-b338-48c6da9e8f3c 2118-9773 3850626 D26E7E13-35AB-422A-B929-01AEBA7AB0A4 Gabonorygma sergipana gen. et sp. nov. urn:lsid:zoobank.org:act: 185D3B61-6920-4DFA-89CA-260C37B43608 Fig. 7 I–R “ Asciocythere” GA E 26 – Grosdidier 1979: 8 , fig. 58a–c. Ovocytheridea aff. reniformis van den Bold, 1964 – Viviers et al. 2000: 425 , figs 14.3–14.4. Pattersoncypris ? sp. 1 – Piovesan et al. 2013: 244 , fig. 4.3a–b. Diagnosis A species of Gabonorygma gen. nov. distinguished by the following features: carapace with greatest height at the antero-central region and greatest width at the centro-posterior region, round, slightly infra-curvate posterior end and weakly developed inner margin, not visible in the oral region, where the selvage bends inwards expressively. Etymology From Sergipe State , Brazil , where the species was described. Type material Holotype BRAZIL : ♀ , carapace, stored dry in a micropaleontological slide (CP-698). Allotype BRAZIL : ³, carapace, stored as the holotype (CP-699). Paratypes BRAZIL : ♀ , carapace (CP-700), ♀ , carapace (CP-701), ♀ , valve (CP-702) and ³, carapace (CP-703); stored as the holotype . Other material examined BRAZIL : 1-US-1 well, Laranjeiras Municipality, Sergipe State (depths of 399, 450, 1011, 1020 and 1080 m); 7-CP-252 well, Santo Amaro das Brotas Municipality, Sergipe State (depth of 512.7 m ); Fazenda Santa Bárbara outcrop, Rosário do Catete Municipality, Sergipe State (sample MP-1419), approximate coordinates 10°39' S , 37°01' W ; Penha outcrop, Riachuelo Municipality, Sergipe State (samples MP-1450 to MP-1452 and MP-1459), approximate coordinates 10°42' S , 37°13' W ; Porto dos Barcos 3 outcrop, Riachuelo Municipality, Sergipe State (samples MP-1460, MP-1461, MP-1463, MP-1465 and MP-1468 to MP-1472), approximate coordinates 10°43' S , 37°10' W ; São José 1 outcrop, Riachuelo Municipality, Sergipe State (samples MP-1550 to MP-1565), approximate coordinates 10°44' S , 37°13' W . Type locality and stratum Sample MP-1472, Porto dos Barcos 3 outcrop, Riachuelo Municipality, Sergipe State , Brazil , approximate coordinates: 10°43' S , 37°10' W ; Riachuelo Formation, Sergipe-Alagoas Basin, middle Albian, Aracajuia benderi zone (MSA-0), Praebythoceratina amsittenensis subzone (MSA-0.3). Fig. 7. [facing page] Ostracods of the Riachuelo Formation, Sergipe-Alagoas Basin, Albian, Brazil. – A–C . Xestoleberis ? sp. 2; CP-697. A . Right lateral view. B . Left lateral view. C . Dorsal view. – D–H . Apatocythere ? sp. 1. D–E . CP-763. D . Right lateral view. E . Dorsal view. F–H . CP-762. F . Right lateral view. G . Left lateral view. H . Dorsal view. – I–R . Gabonorygma sergipana gen. et sp. nov. I . CP-698, right lateral view. J . CP-700, left lateral view. K . CP-701, dorsal view. L . CP-703, dorsal view. M . CP-699, right lateral view. N–R . CP-702. N . Left internal view. O . Detail of the hinge. P . Interpretation of the hinge structures. Q . Detail of the central and anterior muscle scars. R . Interpretation of the central and anterior muscle scars. – S . Aracajuia fragilis ( Piovesan & Nicolaidis, 2013 ) comb. nov. ; CP-764, left lateral view. – T . Microceratina ? sp. 1; CP-714, left lateral view. – U . Algeriana ? sp. 1; CP-727, left lateral view. Scale bars = 100 μm. Measurements Holotype (CP-698): ♀ , carapace: length = 0.40 mm , height = 0.23 mm , width = 0.21 mm . Allotype (CP-699): ³, carapace: length = 0.40 mm , height = 0.22 mm , width = 0.17 mm . Paratype (CP-700): ♀ , carapace: length = 0.38 mm , height = 0.22 mm , width = 0.20 mm . Paratype (CP-701): ♀ , carapace: length = 0.40 mm , height = 0.23 mm , width = 0.21 mm . Paratype (CP-702): ♀ , left valve: length = 0.37 mm , height = 0.22 mm . Paratype (CP-703): ³, carapace: length = 0.38 mm , height = 0.20 mm , width = 0.17 mm . Description In lateral view, sub-rounded to sub-rectangular carapace, with greatest height at antero-central and greatest length at central regions. Left valve larger than the right, slightly overlapping it at ventral margin and posterior end. Round anterior end, becoming slightly rectilinear close to dorsal margin, forming an obtuse cardinal angle. Round, slightly infra-curvate posterior end; obtuse posterior cardinal angle. Slightly rectilinear to concave dorsal margin. Rectilinear ventral margin. Smooth overall ornamentation. In dorsal view, elliptical, with greatest width at centro-posterior region. In internal view, adont hinge, composed of smooth bar in left valve. Weakly developed inner lamella, not visible in oral region, where valve margin bends inwards expressively. Selvage visible through entire free margin. Central muscle scar group consisting of at least three elliptical central scars oriented in its greatest axis from anteroventral to postero-dorsal margins and an elliptical frontal scar. Weak sexual dimorphism: females more sub-rounded and wider in dorsal view, males more sub-rectangular and narrower. Remarks Gabonorygma sergipana gen. et sp. nov. can be separated from Gabonorygma brotzeni by the more rounded shape of its posterior end, the more anterior position of its greatest height and the more central position of its greatest width. Specimens in Grosdidier et al. (1979) , Piovesan et al. (2013) and Viviers et al. (2000) also belong to the new species. Paleoecology and distribution Gabonorygma sergipana gen. et sp. nov. is a marine, shelf species occurring in the following localities and stages: Madiéla Formation, Gabon Basin, Gabon , lower–middle Albian ( Grosdidier 1979 ). Angico ( Viviers et al. 2000 ) and Taquari (present work) Members, Riachuelo Formation, Sergipe-Alagoas Basin, uppermost Aptian–Albian, Aracajuia benderi (MSA-0) and Aracajuia antiqua (MSA-1) zones, Brazil .