Cristianini Trescastro Bergue

Ostracodes from the Upper Cretaceous deposits of the Potiguar Basin, northeastern Brazil: taxonomy, paleoecology and paleobiogeography. Part 2: Santonian-Campanian

Sixty-four Ostracoda taxa were recorded from the Santonian–Campanian of Potiguar Basin, northeastern Brazil. The following new species were described: Triebelina anterotuberculata, Triebelina obliquocostata, Cophinia ovalis, Fossocytheridea potiguarensis, Ovocytheridea anterocompressa, Ovocytheridea triangularis, Perissocytheridea jandairensis, Semicytherura musacchioi and Protocosta babinoti. The faunal association indicates predominantly shallow marine environments, intercalated with typically mixohaline levels. These species are mostly endemic, although the presence of six species common to West and North Africa shows that migration was still possible by the end of the Cretaceous.

Eocene-Pliocene deep sea ostracodes from ODP site 744A, Southern Indian Ocean

The Eocene-Pliocene deep sea ostracodes from the ODP site 744A (Kerguelen Plateau) are herein studied under the taxonomic and paleoecologic aspects. 28 species are identified, being the genera Krithe, Cytherella and Dutoitella the most diversified. A faunal threshold was recorded in the Early Oligocene, which is tentatively explained under the knowledge of the paleoceanographical studies carried out not only in the Kerguelen Plateau but also in adjacent areas. The faunal turnover and variations in both richness and abundance possibly reflect the inception of psychrosphere and the influence of hydrological changes in the preservation of carapaces. Moreover, the influence of those changes on carbonate preservation is discussed as the cause of faunal impoverishment in the upper portion of the core.

The Paleocene-Oligocene Ostracodes from DSDP Site 329 (Falkland Plateau): Taxonomy and Paleozoogeographical Remarks

Abstract. This article presents a taxonomic study of the Late Paleocene-Oligocene ostracode faunas of DSDP (Deep Sea Drilling Project) Site 329, Falkland Plateau. Six species were identified at specific level: Actinocythereis orientalis Guernet, Dutoitella mimica Dingle, Legitimocythere presequenta (Benson), Anebocythereis hostizea (Hornibrook), Poseidonamicus pseudorobustus Coles and Whatley, and Abyssocythere diagrenona (Guernet). Nineteen species were left in open nomenclature, one of them as gen. et sp. indet. Krithe, Cytherella, Cytherelloidea and Pennyella (two species each) are the richest genera. Three faunal groups are identified with characteristic associations, as follows: the Paleocene Fauna—PAF (A. hostizea-Abyssocythere diagrenona-Cytheropteron sp.-D. mimica), the Eocene Fauna-EOF (A. orientalis—Cytherelloidea sp. 2—Pennyella spp.) and the Oligocene Fauna—OLF (P. pseudorobustus—Ambocythere sp.—Krithe morkhoveni lamellalata). Preservational aspects linked to carapace dissolution and their relation to the paleoceanographical context are briefly discussed.

Taxonomy and bathymetric distribution of the outer neritic/upper bathyal ostracodes (Crustacea: Ostracoda) from the southernmost Brazilian continental margin

Sixty-five ostracode species belonging to 41 genera and 17 families were recorded in the outer shelf and upper slope off Rio Grande do Sul and Santa Catarina states, southernmost Brazil, between 100 and 586 m water depth interval. The ostracode occurrences are hypothesized to be influenced by both, the coastal waters and the Antarctic Intermediate Water (AAIW). The taxonomy of some species of Bradleya Hornibrook, 1952, Legitimocythere Coles & Whatley, 1989 and Henryhowella Puri, 1957 previously described in the same study area is revised. Bradleya gaucha sp. nov., Legitimocythere megapotamica sp. nov., Apatihowella acelos sp. nov., Apatihowella capitulum sp. nov., Apatihowella besnardi sp. nov., Apatihowella convexa sp. nov., and Aversovalva tomcronini sp. nov. are herein proposed. Trachyleberis aorata Bergue & Coimbra, 2008 is reassigned to the genus Legitimocythere and Bradleya pseudonormani Ramos et al., 2009 has its diagnosis emended. Bythocypris praerenis Brandão, 2008 is considered a junior synonym of Bythocypris kyamos Whatley et al., 1998a. Apatihowella Jellinek & Swanson, 2003 and Legitimocythere species have well-defined bathymetric distributions and are potential paleoceanographic markers for the Quaternary in the Southern Brazilian Margin.

Paleolimnological inferences based on Oligocene ostracods (Crustacea: Ostracoda) from Tremembé Formation, Southeast Brazil

Non-marine Oligocene ostracods from Tremembé Formation (Taubaté Basin, Southeast Brazil) are studied for the first time. The study reveals rich assemblages which are probably composed of many new taxa, two of which are described here. The sixteen ostracod species registered are classified in the generaCypretta Vávra, Strandesia Stuhlmann,Potamocypris Brady, Heterocypris Claus,Eucypris Vávra, Herpetocypris Brady and Norman, Cytheridella Daday and LimnocythereBrady. Two new species of the latter are herein proposed: L. mandubi sp. nov. and L. katu sp. nov. The succession of ostracod assemblages along the studied core changes conspicuously in composition, abundance and preservation, and are characterized by the following associations: Herpetocypris-Cytheridella (lower), Limnocythere-Cypretta (middle) andPotamocypris-Heterocypris (upper). It is assumed that these associations represent different ecological phases of the paleolake Taubaté which is in accordance to previous stratigraphic and paleontological studies in the basin. The results from this pioneering taxonomic and paleoecological study on ostracods from Tremembé Formation reinforce the potential of these fossils for paleolimnological researches in Brazilian Cenozoic deposits.