Search

Superfamily CYTHEROIDEA Baird, 1850 FAMILY Copytidae fam. nov. Coimbra, Bergue & Ramos Type-genus. Copytus Skogsberg, 1939, by present designation. Diagnosis. Carapace elongate, barely calcified in most species. Dorsal and ventral margins parallel or subparallel, posterior margin rounded, anterior margin rounded or protruded in the ventral half. Surface smooth or ornamented by striae and/or ribs, more rarely partially gently reticulate. Normal pore canals simple, small and scattered, usually poorly visible. Inner lamella wide, more developed anteriorly, in some species narrow ventrally. A conspicuous vestibule occurs at each end margin, larger anteriorly. Marginal pore canals simple and straight, in some species some false. Hinge very long, adont, more rarely weakly lophodont, without terminal teeth. Central muscle scars often weakly developed. Adductors a rounded group of four somewhat ovate or subtriangular imprints. Frontal scar usually ovate, generally relatively far from the adductors. Sexual dimorphism of carapace absent or few developed, with males more elongate. Remarks. The muscle scars pattern separates Copytidae from all other modern or fossil Cytheroidea. Copytus and Neocytherideis Puri (family Neocytherideidae) should be closely related based on carapace morphology. However, Copytus has a proportionally longer hinge line, which is not confined to the posterior half of the length, as is the case in most species of Neocytherideis. In Neocytherideis the adductor scars are in a vertical or arcuate line of four imprints with a somewhat U- or V-shaped frontal scar, and the hinge is lophodont. Soft parts few known (see Skogsberg 1939 for the type-species of Copytus). Stratigraphic and geographic distributions. As this family currently has only one genus, see the respective data for Copytus., Published as part of Coimbra, Jo��o Carlos, Bergue, Cristianini Trescastro & Ramos, Maria In��s Feij��, 2020, Is Copytus Skogsberg, 1939 (Crustacea: Ostracoda) a neocytherideid? With description of a new family and two new species, pp. 177-194 in Zootaxa 4729 (2) on pages 185-186, DOI: 10.11646/zootaxa.4729.2.2, http://zenodo.org/record/3632249, {"references":["Baird, W. (1850) The Natural History of the British Entomostraca. Ray Society, London, 364 pp. https: // doi. org / 10.5962 / bhl. title. 1807","Skogsberg, T. (1939) A new genus and species of marine ostracods from South Georgia. Proceedings of the California Academy of Sciences, Series 4, 23, 415 - 425."]}

Coimbra, João Carlos, Bergue, Cristianini Trescastro, Ramos, Maria Inês Feijó (2020): Is Copytus Skogsberg, 1939 (Crustacea: Ostracoda) a neocytherideid? With description of a new family and two new species. Zootaxa 4729 (2): 177-194, DOI: https://doi.org/10.11646/zootaxa.4729.2.2

Copytus wuerdigae sp. nov. (Fig. 2: 6���14; Tab. 1) 1980 Copytus sp. Madeira-Falcetta et al.: 107, pl. 3, fig. 3. 2005 Copytus sp. 2 Machado et al.: 240, pl. 1, fig. 16. 2017 Copytus sp. Morais & Coimbra: fig. 4D. Etymology. In honour of Dr. Norma L. W��rdig for her important studies on living and fossil ostracods from Brazil. Type locality. Southern Brazilian continental shelf, Geomar VI, sample GVI-349 (31��24���; 50��30���W, 60 m water depth, biodetritic silty sand). Age. Recent. Material. 32 valves and one carapace of both adults and latest instars. Holotype. MP-O- 2755 female RV, l: 0.73 mm, h: 0.25 mm (sample Geomar VI-349). Paratypes. MP-O-2756 female LV, l: 0.77 mm, h: 0.27 mm (sample Geomar VI-349); MP-O-2757 female RV, l: 0.77 mm, h: 0.25 mm (sample Geomar VI-349); MP-O-2758 female LV, l: 0.79 mm, h: 0.25 mm (sample M6738); MP-O-2759 female C, l: 0.76 mm, h: 0.25 mm, w: 0.21 mm (sample Geomar VI-349); MP-O-2760 male LV, l: 0.68 mm, h: 0.22 mm (sample L7-3949); MP-O-2761 male LV, l: 0.68 mm, h: 0.18 mm (sample L7-3955). Diagnosis. Medium sized carapace, anterior end extended in ventral half, posterior end asymmetrically rounded. Surface predominantly smooth, with ventro-lateral striae that extend anteriorly as four weak subparallel marginal ribs. Inner lamella wide, particularly anteriorly; very narrow mid-ventrally. Description. Carapace medium sized, thin-shelled, and subcylindrical. A weak ventral overlap of the LV over the RV. Anterior margin extended in ventral half, convex in dorsal one. Posterior margin asymmetrically rounded and slightly upturned. Dorsal and ventral margins straight and parallel. Cardinal angles obtuse. Maximum length subventral. Height fairly uniform along length. In dorsal view, posterior end blunt, anterior end acute, and width relatively uniform, convergent anteriorly. Shell surface predominantly smooth. The anterior third of the carapace ventro-laterally striate, extending anteriorly as four or five weak subparallel marginal ribs. Inner lamella wide, particularly anteriorly; very narrow mid-ventrally. Anterior vestibule large, very deep. Selvage quite narrow, inconspicuous. Marginal pore canals moderate in number, simple, short anteriorly and posteriorly. Hinge adont.Adductor muscle scars as for the genus, forming a very small, subrounded group of four barely visible imprints. Although this genus presents females and males distinguished by the copulatory organs, since Van Morkhoven (1963) it is known that sexual differences are not clear in the hard parts of Copytus. However, we identified sexual dimorphism in the carapace of this new species, i.e., males are smaller and lower than females. Geographic and stratigraphic distribution. In this study, Copytus wuerdigae sp. nov. was found in modern sediments along the southern Brazilian coast between the Rio Grande do Sul State (33��52���S) and the Rio de Janeiro State (22��36���S) (see Tab. 1). It was reported from the Quaternary deposits of Rio Grande do Sul coastal plain (southernmost Brazil) by Madeira-Falcetta et al. (1980). Machado et al. (2005) recorded this species off Cabo Frio, in the Rio de Janeiro State, however, they did not report the number of specimens collected. In a pers. comm. in April 2018, Cl��udia Pinto Machado informed the first author that the distribution by sample was not published in 2005, but that 27 valves and eight carapaces were collected between 41 and 75 m on silt or fine sand. Remarks. Notwithstanding the similarity of the present species with Copytus caligula Skogsberg, 1939 and C. malumiani Echevarr��a, 1987, these three species differ in ornamentation and size. The Skogsberg���s species has a smoother and larger carapace. In turn, C. malumiani is shorter and with a rather less protruded anterior end, besides a different pattern of anteroventral ribs and a characteristic depression perpendicular to the anterodorsal margin. Neocytherideis impudicus [impudica] Whatley, Moguilevsky, Chadwick, Toy & Ramos, 1998, with occurrences in Argentina and Brazil, is somewhat similar to C. wuerdigae sp. nov., but in addition to the typically neocytherideid internal features, it is more elongate and larger, with a anteroventral ornamentation composed of more robust ribs arranged in a chevron pattern., Published as part of Coimbra, Jo��o Carlos, Bergue, Cristianini Trescastro & Ramos, Maria In��s Feij��, 2020, Is Copytus Skogsberg, 1939 (Crustacea: Ostracoda) a neocytherideid? With description of a new family and two new species, pp. 177-194 in Zootaxa 4729 (2) on pages 187-190, DOI: 10.11646/zootaxa.4729.2.2, http://zenodo.org/record/3632249, {"references":["Van Morkhoven, F. P. C. M. (1963) Post-Palaeozoic Ostracoda, their morphology, taxonomy and economic use. Generic descriptions. Elsevier, Amsterdam, 478 pp.","Madeira-Falcetta, M., Thiesen, Z. V., Kotzian, S. B. & Godolphim, M. F. (1980) Interpretacao de dois testemunhos de sondagem (PDS- 3 e ALB) na planicie costeira do Rio Grande do Sul. Pesquisas, 13, 91 - 107. https: // doi. org / 10.22456 / 1807 - 9806.21751","Machado, C. P., Coimbra, J. C. & Carreno, A. L. (2005) The ecological and zoogeographical significance of the sub-Recent Ostracoda off Cabo Frio, Rio de Janeiro State, Brazil. Marine Micropaleontology, 55, 235 - 253. https: // doi. org / 10.1016 / j. marmicro. 2005.03.002","Skogsberg, T. (1939) A new genus and species of marine ostracods from South Georgia. Proceedings of the California Academy of Sciences, Series 4, 23, 415 - 425.","Echevarria, A. (1987) Ostracodos de la Formacion Carmen Silva, Miembro Superior (Mioceno Inferior), Isla Grande de Tierra del Fuego, Argentina, Parte 1. Ameghiniana, 24, 129 - 139.","Whatley, R. C., Moguilevsky, A., Chadwick, J. Toy, N. & Ramos, M. I. F. (1998) Ostracoda from the South West Atlantic. Part III. The Argentinian, Uruguayan and Southern Brazilian continental Shelf. Revista Espanola de Micropaleontologia, 30, 89 - 116."]}

Copytus fusiformis (Yassini, 1979). Copytus fusiformis (Yassini, 1979) was originally described as Neocytherideis from the Pliocene of SW Algeria and subsequently recorded from the Recent off Morocco (Llano 1981), Senegal (Carbonel et al. 1983) and the Gambia (Witte 1993). The latter author changed the name to Copytus, because it has the cluster of four adductor scars in a small circular group so distinctive of Copytus, although the very elongate cylindrical shape with a narrowly pointed anterior margin below mid-height being perhaps more common in Neocytherideis. Besides, the hinge line is very long and not confined to the posterior half of the length. Witte (1993) notes the ���remarkable similarity��� of this species to Indo-Pacific and Australian species of the genus such as C. rara McKenzie, 1967, Copytus sp. cf. C. rara (in Jain 1978) and C. tubulata (nomen nudum) in Labutis (1977). The Labutis��� species (pl. 11: 11; pl. 23: 6���7), with a small circular cluster of adductor scars and adont hinge, clearly belongs to Copytus. Witte (1993) also registered some similarity to Copytus sp. n. of Bertels & Mart��nez (1990) from the onshore Quaternary of southern Buenos Aires Province, Argentina. Although this Argentinian species is externally similar to C. fusiformis, it is smaller (l = 0.80 mm) and less elongate, and is in the list of synonymies of Neocytherideis impudicus [impudica] Whatley et al., 1998. It is also noteworthy that Copytus sp. of Bertels et al. (1982), recovered from the Quaternary of southernmost Brazil, is another junior synonym of N. impudica. The present authors without hesitation refer Neocytherideis boomeri Dingle, 1992 to the genus Copytus on the grounds of its very long hinge without terminal teeth and subcircular aggregate of four adductor scars, and we also consider it a junior synonym of C. fusiformis (Yassini, 1979). The South African material is very similar in outline, ornamentation and size (l = 0.95���1.00 mm) to the material of C. fusiformis from Gambia (l = 0.93���1.02 mm)., Published as part of Coimbra, Jo��o Carlos, Bergue, Cristianini Trescastro & Ramos, Maria In��s Feij��, 2020, Is Copytus Skogsberg, 1939 (Crustacea: Ostracoda) a neocytherideid? With description of a new family and two new species, pp. 177-194 in Zootaxa 4729 (2) on pages 183-184, DOI: 10.11646/zootaxa.4729.2.2, http://zenodo.org/record/3632249, {"references":["Yassini, I. (1979) Repartition des ostracodes dans une serie marine regressive d'age pliocene dans la region d'Alger, Algerie. Revue de Micropaleontologie, 22, 89 - 124.","Llano, M. (1981) Interet des Ostracodes dans l'interpretation des phenomenes hydrologiques sur les plateaux continentaux: la plate-forme atlantique marocaine. These Doctorat Etat, Universite de Bordeaux, Bordeaux, 256 pp.","Carbonel, P., Pinson, J., Riffault, A., Peypouquet, J. - P. & Tastet, J. - P. (1983) Les ostracodes du plateau continental senegalais: temoins des environnements actuels et quaternaires. Bulletin de Liaison de l'Association Senegalaise d'Etudes du Quaternaire Africain, 70 / 71, 15 - 36.","Witte, L. J. (1993) Taxonomy and biogeography of West African beach ostracods. Verhandelingen Koninklijke Nederlandse Akademie van Wetenschappen, Natuurkunde, 39, 13 - 105.","McKenzie, K. G. (1967) Recent Ostracoda from Port Phillip Bay, Victoria. Proceedings of the Royal Society of Victoria, 80, 61 - 106.","Jain, S. P. (1978) Recent Ostracoda from Mandvi beach, west coast of India. Bulletin of the Indian Geologists Association, 11, 89 - 139.","Labutis, V. R. (1977) Cytheracean Ostracoda from the Great Barrier Reef. M. Sc. thesis, Macquarie University, Sydney, 374 pp.","Bertels, A. & Martinez, D. E. (1990) Quaternary ostracodes of continental and transitional shallow marine environment. Courier Forschungsinstitut Senckenberg, 123, 141 - 159.","Whatley, R. C., Moguilevsky, A., Chadwick, J. Toy, N. & Ramos, M. I. F. (1998) Ostracoda from the South West Atlantic. Part III. The Argentinian, Uruguayan and Southern Brazilian continental Shelf. Revista Espanola de Micropaleontologia, 30, 89 - 116.","Bertels, A., Kotzian, S. C. B. & Madeira-Falcetta, M. (1982) Micropaleontologia (foraminiferos y ostracodos) del Cuaternario de Palmares do Sul (Formacion Chui), Brasil. Ameghiniana, 19, 125 - 156.","Dingle, R. V. (1992) Quaternary ostracods from the continental margin off south-western Africa. Part 1. Dominant taxa. Annals of the South African Museum, 102, 1 - 89."]}

Copytus wuerdigae sp. nov. (Fig. 2: 6–14; Tab. 1) 1980 Copytus sp. Madeira-Falcetta et al.: 107, pl. 3, fig. 3. 2005 Copytus sp. 2 Machado et al.: 240, pl. 1, fig. 16. 2017 Copytus sp. Morais & Coimbra: fig. 4D. Etymology. In honour of Dr. Norma L. Würdig for her important studies on living and fossil ostracods from Brazil. Type locality. Southern Brazilian continental shelf, Geomar VI, sample GVI-349 (31°24’; 50°30’W, 60 m water depth, biodetritic silty sand). Age. Recent. Material. 32 valves and one carapace of both adults and latest instars. Holotype. MP-O- 2755 female RV, l: 0.73 mm, h: 0.25 mm (sample Geomar VI-349). Paratypes. MP-O-2756 female LV, l: 0.77 mm, h: 0.27 mm (sample Geomar VI-349); MP-O-2757 female RV, l: 0.77 mm, h: 0.25 mm (sample Geomar VI-349); MP-O-2758 female LV, l: 0.79 mm, h: 0.25 mm (sample M6738); MP-O-2759 female C, l: 0.76 mm, h: 0.25 mm, w: 0.21 mm (sample Geomar VI-349); MP-O-2760 male LV, l: 0.68 mm, h: 0.22 mm (sample L7-3949); MP-O-2761 male LV, l: 0.68 mm, h: 0.18 mm (sample L7-3955). Diagnosis. Medium sized carapace, anterior end extended in ventral half, posterior end asymmetrically rounded. Surface predominantly smooth, with ventro-lateral striae that extend anteriorly as four weak subparallel marginal ribs. Inner lamella wide, particularly anteriorly; very narrow mid-ventrally. Description. Carapace medium sized, thin-shelled, and subcylindrical. A weak ventral overlap of the LV over the RV. Anterior margin extended in ventral half, convex in dorsal one. Posterior margin asymmetrically rounded and slightly upturned. Dorsal and ventral margins straight and parallel. Cardinal angles obtuse. Maximum length subventral. Height fairly uniform along length. In dorsal view, posterior end blunt, anterior end acute, and width relatively uniform, convergent anteriorly. Shell surface predominantly smooth. The anterior third of the carapace ventro-laterally striate, extending anteriorly as four or five weak subparallel marginal ribs. Inner lamella wide, particularly anteriorly; very narrow mid-ventrally. Anterior vestibule large, very deep. Selvage quite narrow, inconspicuous. Marginal pore canals moderate in number, simple, short anteriorly and posteriorly. Hinge adont.Adductor muscle scars as for the genus, forming a very small, subrounded group of four barely visible imprints. Although this genus presents females and males distinguished by the copulatory organs, since Van Morkhoven (1963) it is known that sexual differences are not clear in the hard parts of Copytus. However, we identified sexual dimorphism in the carapace of this new species, i.e., males are smaller and lower than females. Geographic and stratigraphic distribution. In this study, Copytus wuerdigae sp. nov. was found in modern sediments along the southern Brazilian coast between the Rio Grande do Sul State (33°52’S) and the Rio de Janeiro State (22°36’S) (see Tab. 1). It was reported from the Quaternary deposits of Rio Grande do Sul coastal plain (southernmost Brazil) by Madeira-Falcetta et al. (1980). Machado et al. (2005) recorded this species off Cabo Frio, in the Rio de Janeiro State, however, they did not report the number of specimens collected. In a pers. comm. in April 2018, Cláudia Pinto Machado informed the first author that the distribution by sample was not published in 2005, but that 27 valves and eight carapaces were collected between 41 and 75 m on silt or fine sand. Remarks. Notwithstanding the similarity of the present species with Copytus caligula Skogsberg, 1939 and C. malumiani Echevarría, 1987, these three species differ in ornamentation and size. The Skogsberg’s species has a smoother and larger carapace. In turn, C. malumiani is shorter and with a rather less protruded anterior end, besides a different pattern of anteroventral ribs and a characteristic depression perpendicular to the anterodorsal margin. Neocytherideis impudicus [impudica] Whatley, Moguilevsky, Chadwick, Toy & Ramos, 1998, with occurrences in Argentina and Brazil, is somewhat similar to C. wuerdigae sp. nov., but in addition to the typically neocytherideid internal features, it is more elongate and larger, with a anteroventral ornamentation composed of more robust ribs arranged in a chevron pattern.

Copytus elongatus Benson, 1964. While C. laevata (senior synonym of C. caligula) is rather thin-shelled, another Antarctic species Copytus elongatus Benson, 1964, is more robust. It is smaller (l = 0.79–0.83 mm) than C. laevata (l = 0.94–1.02 mm), but also has vestibulae in both ends, and few short marginal pore canals, although numerous are false. Its hinge is similarly adont, but more robust, and its outline is rounded anteriorly and posteriorly. The adductor muscles leave an obscure small cluster of scars; the frontal scar is not visible in this species. Apart from its stronger shell and more robust hinge, Benson (1964, p. 17) stated that C. elongatus differs from C. laevata by its “narrower-mouthed, deep anterior vestibule and shallower posterior vestibule.” Neale (1967, p. 28) separated these two species mainly on their length: height ratio. He demonstrated that in his material of C. elongatus and Benson’s type material the height of the specimens varied between about 41 and 43% of the length compared with about 33% for Skogsberg’s C. caligula from South Georgia, 33 to 39% for Brady’s type material of C. laevata from Heard Island and 39% for Chapman’s (1916) Quaternary material from the Drygalski Glacier (Antarctic Peninsula). Neale’s photographs (pl. I, figs q, q’, r, r’) emphasised the very straight and parallel dorsal and ventral margins of C. elongatus. Benson’s species is recorded widely throughout Antarctic waters, the most northerly record being in the South Orkney Islands. Benson (1964) and Neale (1967) record it from McMurdo Sound and Halley Bay, respectively, and Hartmann (1997) from a number of localities including the Bransfield Strait, Elephant Island, King George Island, Adelaide Island and Faraday Station. Hartmann (1997, p. 75) gave a synonymy of the species, which, however, excluded the record by D’Onofrio & Pugliese (1989 apud Hartmann 1997) from the Ross Sea.

Copytus elongatus Benson, 1964. While C. laevata (senior synonym of C. caligula) is rather thin-shelled, another Antarctic species Copytus elongatus Benson, 1964, is more robust. It is smaller (l = 0.79���0.83 mm) than C. laevata (l = 0.94���1.02 mm), but also has vestibulae in both ends, and few short marginal pore canals, although numerous are false. Its hinge is similarly adont, but more robust, and its outline is rounded anteriorly and posteriorly. The adductor muscles leave an obscure small cluster of scars; the frontal scar is not visible in this species. Apart from its stronger shell and more robust hinge, Benson (1964, p. 17) stated that C. elongatus differs from C. laevata by its ���narrower-mouthed, deep anterior vestibule and shallower posterior vestibule.��� Neale (1967, p. 28) separated these two species mainly on their length: height ratio. He demonstrated that in his material of C. elongatus and Benson���s type material the height of the specimens varied between about 41 and 43% of the length compared with about 33% for Skogsberg���s C. caligula from South Georgia, 33 to 39% for Brady���s type material of C. laevata from Heard Island and 39% for Chapman���s (1916) Quaternary material from the Drygalski Glacier (Antarctic Peninsula). Neale���s photographs (pl. I, figs q, q���, r, r���) emphasised the very straight and parallel dorsal and ventral margins of C. elongatus. Benson���s species is recorded widely throughout Antarctic waters, the most northerly record being in the South Orkney Islands. Benson (1964) and Neale (1967) record it from McMurdo Sound and Halley Bay, respectively, and Hartmann (1997) from a number of localities including the Bransfield Strait, Elephant Island, King George Island, Adelaide Island and Faraday Station. Hartmann (1997, p. 75) gave a synonymy of the species, which, however, excluded the record by D���Onofrio & Pugliese (1989 apud Hartmann 1997) from the Ross Sea., Published as part of Coimbra, Jo��o Carlos, Bergue, Cristianini Trescastro & Ramos, Maria In��s Feij��, 2020, Is Copytus Skogsberg, 1939 (Crustacea: Ostracoda) a neocytherideid? With description of a new family and two new species, pp. 177-194 in Zootaxa 4729 (2) on page 183, DOI: 10.11646/zootaxa.4729.2.2, http://zenodo.org/record/3632249, {"references":["Benson, R. H. (1964) Recent Cytheracean Ostracodes from McMurdo Sound and the Ross Sea, Antarctica. The University of Kansas Paleontological Contributions, Arthropoda, 6, 1 - 36.","Neale J. W. (1967) An ostracod fauna from Halley Bay, Coast Land, British Antarctic Territory. British Antarctic Survey Scientific Reports, 58, 1 - 59.","Chapman, F. (1916) Report on the Ostracoda and Foraminifera from elevated deposits on the shores of the Ross Sea. Section 2. Ostracoda from upthrust muds above the Drygalski Glacier. In: British Antarctic Expedition 1907 - 1909. Reports of the Scientific Investigations. Geology. Vol. 2. Contributions to the palaeontology and petrology of south Victoria Land. Pt. 3. William Heineman, London, pp. 55 - 80.","Hartmann, G. (1997) Antarktische und Subantarktische Podocopa (Ostracoda). In: Wagele, J. W. & Sesieg, J. (Eds.), Synopses of the Antarctic Benthos. Teil 7. Koeltz Scientific Books, Koenigstein, pp. 9 - 355."]}

Copytus fusiformis (Yassini, 1979). Copytus fusiformis (Yassini, 1979) was originally described as Neocytherideis from the Pliocene of SW Algeria and subsequently recorded from the Recent off Morocco (Llano 1981), Senegal (Carbonel et al. 1983) and the Gambia (Witte 1993). The latter author changed the name to Copytus, because it has the cluster of four adductor scars in a small circular group so distinctive of Copytus, although the very elongate cylindrical shape with a narrowly pointed anterior margin below mid-height being perhaps more common in Neocytherideis. Besides, the hinge line is very long and not confined to the posterior half of the length. Witte (1993) notes the “remarkable similarity” of this species to Indo-Pacific and Australian species of the genus such as C. rara McKenzie, 1967, Copytus sp. cf. C. rara (in Jain 1978) and C. tubulata (nomen nudum) in Labutis (1977). The Labutis’ species (pl. 11: 11; pl. 23: 6–7), with a small circular cluster of adductor scars and adont hinge, clearly belongs to Copytus. Witte (1993) also registered some similarity to Copytus sp. n. of Bertels & Martínez (1990) from the onshore Quaternary of southern Buenos Aires Province, Argentina. Although this Argentinian species is externally similar to C. fusiformis, it is smaller (l = 0.80 mm) and less elongate, and is in the list of synonymies of Neocytherideis impudicus [impudica] Whatley et al., 1998. It is also noteworthy that Copytus sp. of Bertels et al. (1982), recovered from the Quaternary of southernmost Brazil, is another junior synonym of N. impudica. The present authors without hesitation refer Neocytherideis boomeri Dingle, 1992 to the genus Copytus on the grounds of its very long hinge without terminal teeth and subcircular aggregate of four adductor scars, and we also consider it a junior synonym of C. fusiformis (Yassini, 1979). The South African material is very similar in outline, ornamentation and size (l = 0.95–1.00 mm) to the material of C. fusiformis from Gambia (l = 0.93–1.02 mm).

Ostracodes são microcrustáceos que possuem uma carapaça bivalve constituída por quitina e carbonato de cálcio, que vivem em ambientes marinhos e não-marinhos. São amplamente utilizados em estudos paleoceanográficos e paleoclimáticos, sendo bons indicadores batimétricos, de salinidade e de temperatura. Nas bacias brasileiras, os ostracodes têm larga aplicação bioestratigráfica, especialmente em intervalos não marinhos cretáceos. Por sua vez, os ostracodes marinhos têm se destacado pelos bons resultados paleoceanográficos em bacias marginais, entre elas a Bacia de Pelotas. Este trabalho propõe novas espécies eomiocênicas da família Cytherellidae e do gênero Actinocythereis. A partir do estudo taxonômico discutem-se implicações paleozoogeográficas de eventos como o estabelecimento da Corrente Circumpolar Antártica e da Corrente das Malvinas, cuja ação influenciou a dispersão dos ostracodes ora registrados na Bacia de Pelotas. A partir da análise do intervalo testemunhado 1300 m-1318 m do poço offshore 2-RSS-1 coletado pela Petrobras na década de 1970, são registradas cinco espécies da família Cytherellidae, duas das quais aqui descritas, como segue: Inversacytherella atlantica sp. nov., Cytherella pelotensis sp. nov., Cytherella sp. 1, Cytherella sp. 2 e Grammcythella? sp. É também proposta Actinocythereis imbeensis sp. nov., a qual constitui a segunda espécie descrita para o gênero no Brasil. São ainda registradas, Krithe coimbrai, Krithe gnoma e Henryhowella kempfi, atribuídas em trabalhos anteriores ao estabelecimento de massas de água frias na costa Sul-Brasileira. As ocorrências de Inversacytherella e Grammcythella, por sua vez, constituem evidências para o intercâmbio faunístico entre a América e a Oceania decorrentes de mudanças hidrológicas no Oceano Austral ao longo do Neogeno. O Apêndice 1 apresenta a lista e a documentação fotográfica das demais espécies registradas. Ostracods are microcrustaceans with a bivalve carapace composed by chitin and calcium carbonate, living in both marine and non-marine environments. They are broadly used in paleoceanographic and paleoclimatic studies as indicators of bathymetry, salinity and temperature. In the Brazilian sedimentary basins the ostracodes have biostratigraphic importance, mainly in Cretaceous non-marine sections. The marine species, on the other hand, supply good paleoceanographyc data in marginal basins, including Pelotas Basin. In this work new Early Miocene species of the family Cytherellidae and the of genus Actinocythereis are proposed. Based on this taxonomic study some paleozoogeographic remarks are made, linking to the inception of the Antarctic Circumpolar Current and the Malvinas Current, to the dispersal of the ostracodes recorded in the Pelotas Basin. From the analysis of the core section 1300 m-1318 m of the offshore well 2-RSS-1 drilled by Petrobras in the 1970 decade, five species of cytherellids are recorded, two of them herein described, as follows: Inversacytherella atlantica sp. nov., Cytherella pelotensis sp. nov., Cytherella sp. 1, Cytherella sp. 2 and Grammcythella? sp. It is also proposed Actinocythereis imbeensis sp. nov., which constitutes the second species described for the genus in Brazil. Moreover, Krithe coimbrai, Krithe gnoma and Henryhowella kempfi, assigned in previous studies to the inception of cool water masses in Southern Brazilian coast, are recorded. The presence of Inversacytherella and Grammcythella, supply additional evidence for the faunal interchange between America and Oceania influenced by hydrological events in Southern Ocean along the Neogene. The Appendix 1 features the list and photographic documentation of other species registered.

Submitted by Mariana Dornelles Vargas (marianadv) on 2015-03-19T12:24:18Z No. of bitstreams: 1 ostracodes_cretaceos.pdf: 7126206 bytes, checksum: aeab76d69d08b602eaba4e755811f341 (MD5) Made available in DSpace on 2015-03-19T12:24:18Z (GMT). No. of bitstreams: 1 ostracodes_cretaceos.pdf: 7126206 bytes, checksum: aeab76d69d08b602eaba4e755811f341 (MD5) Previous issue date: 2008-08-11 CENPES - Centro de Pesquisas e Desenvolvimento Leopoldo Américo Miguez de Mello Neste trabalho apresentam-se os resultados do estudo taxonômico dos ostracodes marinhos da Bacia do Pará-Maranhão, no intervalo Turoniano-Maastrichtiano, e das respostas paleoambientais e de distribuição paleobiogeográfica das assembléias. O material analisado constituiu-se de 65 amostras de calha, provenientes de dois poços, denominados 1-MAS-12 e 1-MAS-16. O poço 1-MAS-16 possui profundidade entre 3552-4990 m, de idade Turoniano-Maastrichtiano e o poço 1-MAS-12 com profundidade entre 2145-2685 m, abrangendo o Campaniano-Maastrichtiano. A abundância registrada totalizou 841 espécimes, identificados em 61 espécies, incluídos em 30 gêneros, pertencentes a 13 famílias. As espécies identificadas foram as seguintes: Macrocypris longana Bold, 1960; Bairdoppilata cespedesensis (Bold, 1946); Isocythereis carlsbardensis Holden, 1964; Protobuntonia numidica Grekoff, 1954; Loxoconcha safeni Sarr, 1998; Krithe cushmani Alexander, 1929; Paracypris cf. P. gracilis (Bosquet, 1854); Ovocytheridea cf. O. aegyptiaca Morsi, 2000; Cytheropteron cf. C. brasiliensis Fauth et al., 2005; Xestoleberis aff. X. minuta Holden, 1964; 51 espécies foram deixadas em nomenclatura aberta e 11 táxons permaneceram indeterminados. Os gêneros mais diversificados foram Cytherella, Krithe e Bairdoppilata, com sete, seis e cinco espécies, respectivamente. As variações no nível do mar refletiram-se na constituição das associações faunísticas, evidenciando baixa diversidade e abundância no intervalo Turoniano e Santoniano e, a partir do Maastrichtiano inferior, há um aumento significativo no número de espécimes e espécies, possivelmente associado a um evento regressivo. A partir das características da fauna e de uma minuciosa revisão bibliográfica, foi possível inferir um ambiente de plataforma rasa, em ambos os poços. Na análise paleoecológica também foi discutida a presença expressiva de exemplares de Platycopina e sua associação a níveis disaeróbicos, concluindo-se que os dados não disponíveis foram suficientes para inferir baixos níveis de oxigenação, uma vez que seus picos de abundância ocorrem associados a um grande número de espécies. A tentativa de encontrar uma relação entre a litologia e a ocorrência dos táxons também não apresentou resultados significativos, possivelmente em função do tipo de amostragem (calha). Através do estudo paleobiogeográfico estabeleceram-se afinidades faunísticas, durante o Senoniano, com o noroeste da África e Caribe. This work presents the results of the taxonomic study of the Turonian-Maastrichtian marine ostracodes of Pará-Maranhão Basin, their palaeoenvironmental responses and paleobiogeographical distribution. The 65 studied samples are from two wells: the 1-MAS-16 (3552-4990 m, Turonian-Maastrichtian) and the 1-MAS-12 (2145-2685 m, Campanian-Maastrichtian). 841 specimens were recorded, identified in 61 species, belonging to 30 genera and 13 families. The identified species were: Macrocypris longana Bold, 1960; Bairdoppilata cespedesensis (Bold, 1946); Isocythereis carlsbardensis Holden, 1964; Protobuntonia numidica Grekoff, 1954; Loxoconcha safeni Sarr, 1998; Krithe cushmani Alexander, 1929; Paracypris cf. P. gracilis (Bosquet, 1854); Ovocytheridea cf. O. aegyptiaca Morsi, 2000; Cytheropteron cf. C. brasiliensis Fauth et al., 2005; Xestoleberis aff. X. minuta Holden, 1964; 51 species were left in open nomenclature and 11 taxa remained indeterminate. Cytherella, Krithe and Bairdoppilata were the most diversified genera, with seven, six and five species, respectively. Sea level changes are reflected in the faunistic association, showing low diversity and abundance during the Turonian-Santonian. In the other hand, in the lower Maastrichtian, there is a significant increase in the number of specimens and species, possibly as a consequence of a regressive event. From the characteristics of the association and the literature revision it was possible to infer a shallow environment for both wells. In the paleoecological analysis, the expressive presence of Platycopina and their association with disaerobic levels was also discussed, concluding that there was no relation to oxygen levels, due to the presence of a large number of species. The attempt to link the lithology to the occurrence of taxa had no significative results, possibly due to the sampling type (ditch cuttings). Throughout the paleobiogeographical study faunal affinities have been established for the Senonian, with the Northwest Africa and the Caribbean region.

O presente trabalho envolveu o estudo da microfauna de ostracodes de 10 amostras provenientes de um testemunho de sondagem realizado na porção norte do talude médio da Bacia de Campos, RJ (1287 m de lâmina d'água). As amostras foram tratadas segundo a metodologia padrão para microfósseis calcários. A fauna total de ostracodes foi recuperada e os elementos autóctones foram identificados e estudados. Em conjunto aos dados faunísticos, análises geoquímicas de isótopos estáveis de oxigênio foram realizadas em testas de foraminíferos planctônicos, colaborando com o estudo paleoecológico e paleoceanográfico. Foram identificadas 86 espécies, 46 das quais autóctones, distribuídas em 28 gêneros e 13 famílias. Krithe e Cytheropteron foram os gêneros mais diversificados (sete e quatro espécies, respectivamente), assim como as famílias Cytheruridae e Krithidae, concordando com estudos similares em outras regiões do mundo. A ocorrência de espécies cosmopolitas na Bacia de Campos é marcante, o que reforça a idéia de que a distribuição de algumas espécies tende ao pandemismo em águas profundas. A curva de isótopos estáveis de oxigênio obtida segue a tendência geral das curvas padrões para o oceano Atlântico Sul. A fauna de ostracodes respondeu às mudanças oceanográficas ocorridas no Quaternário da Bacia de Campos, reforçando a potencialidade do grupo como bons indicadores de eventos dessa natureza. Respostas divergentes da diversidade específica foram registradas: baixa diversidade no penúltimo glacial e alta durante o Último Máximo Glacial (UMG). Uma diminuição da diversidade foi notada no final do Holoceno. Distintas associações de espécies ocorreram ao longo das amostras, a primeira e mais antiga caracterizada pelas espécies Australoecia atlantica, Poseidonamicus pintoi, Microcythere cronini, Rimacytheropteron sp. e Krithe reversa., e a segunda representada por Macropyxis sp., Bythoceratina sp., Henryhowella cf. H. asperrima e Krithe trinidadensis. O UMG foi o evento que definiu esta mudança faunística. The present work dealt with the study of ostracods from 10 piston core samples from the northern portion of the Campos Basin slope, Rio de Janeiro (1287 m depth). The samples were treated following the standard methodology for calcareous microfossils. The totality of the ostracode fauna was recovered and its autochtonous elements studied. Along with the faunal data, oxygen stable isotopes analysis were carried out in planctonic foraminifer tests, improving the paleoecological and paleoceanografical studies. Eighty-six species were identified, 46 of them were autochtonous, distributed in 38 genera and 13 families. Krithe and Cytheropteron were the most diversified genera (seven and four species, respectively), as well as the families Cytheruridae and Krithidae, which is in agreement with similar studies carried out in other regions. It is remarkable the occurrence of cosmopolitan species in Campos Basin, reinforcing the idea that deep sea environment species tends to present a pandemic distribution. The oxygen isotope data follow the general pattern of the standard South Atlantic curve. The ostracode fauna has been influenced by oceanographical changes occurred during the Quaternary in the Campos Basin, reinforcing the potentiality of this group as indicators of this kind of event. Divergent responses were registered in the specific diversity: low diversity during penultimate glacial and a higher one in the Last Glacial Maximum (LGM). A diversity reduction was noticed in the Holocene ending. Distinctive species assemblages occurred along the samples, the first and older one characterized by Australoecia atlantica, Poseidonamicus pintoi, Microcythere cronini, Rimacytheropteron sp. and Krithe reversa., and the second one represented by Macropyxis sp., Bythoceratina sp., Henryhowella cf. H. Asperrima and Krithe trinidadensis. LGM was the event which defined this faunal turnover.