Ostracoda

The main distribution area of the Sarmatian sediments in Georgia is the Transcaucasian intermountain area. According to the tectonic zoning scheme of Georgia (Gamkrelidze, 2000), Kartli depression, which is the object of study, participates in the structural-facial composition of the eastern subsidence molassic zone of the Transcaucasian intermountain area. The Sarmatian sediments widespread in this area are distinguished in facies diversity and represent a prospective stratigraphic interval of natural hydrocarbons accumulation.
Over the past years, quite rich factual material has accumulated on the Sarmatian sediments of the Kartli depression, including paleontological and biostratigraphical. The Sarmatian sediments are well studied makro- and micro-faunally and their detailed stratigraphic division has been accomplished as well (Buleishvili, 1960; Gruzinskaya, 1967; Koiava, 2006).
In recent years, during oil exploration special attention is attracted to the identification of paleo-deltas. There was established certain regularity, according to which the largest oil fields are related just to the paleo-deltas. During the oil exploration works micro-paleontological investigations (foraminifers, ostracods) are of special importance.
The Sarmatian deposits of the Kartli depression are well studied, in terms of foraminifers (Koiava, 2006). As for the Ostracods, this group is at the initial stage of the study, and studying them in complex with the foraminifera will make a significant contribution to the paleontological/biostratigraphic knowledge of the region and will help petroleum geologists in hydrocarbon exploration.
That is why the Sarmatian sediments of Kartli Depression have been selected as the topic for the Master's thesis, and the research method is based on micropaleontology (Foraminifera, Otracoda). The aim of the research is establishment of the foraminifera and ostracod complexes of the Kartli depression Sarmatian sediments and according to them determination of biostratigraphic boundaries, stratigraphic division of the studied sediments, monographic study of the Sarmatian foraminifers and ostracods. 
For this purpose, in the limits of Kartli depression we have studied three sections of the Sarmatian sediments: 1 - in the Nadarbazevi ravine; 2 - in the environs of the Bebristsikhe (town of Mtskheta); 3 - in the gorge of river Noriostskali.
As a result of the study, in the Kartli depression, complexes of foraminifers and ostracods characteristic of the Lower and Middle Sarmatian are distinguished. Their regular variability in time and space was established and due to that stratigraphic division of the studied sediments was carried out. 11 species of 3 foraminifer genera and 9 species of 4 ostracod genera are studied monographically. For the first time in the bounds of Kartli depression, a complex study of the Sarmatian sediments based on two groups of microfauna - foraminifers and ostracods was carried out.

In marine environments Ostracoda and Foraminifera have been very successful invaders. During the Phanerozoic they colonised the majority of shallow, marginal to deep water, fully marine habitats. Both groups had developed physiological adaptations which pre-adapted them to the invasion of new marine habitats.
They adopted a broad range of feeding strategies and reproduction modes. The production of resting stages and brood care may also have contributed to them being efficient invaders. They are also both highly tolerant to variations in salinity. The first invasions of non-marine habitats by ostracods appear to have taken place at the turn of the Devonian and Carboniferous. It is estimated that there had been between 9 and 12 independent invasions of fresh waters by the ostracods. In contrast Foraminifera are typically marine organisms, and only a few species of
agglutinated and organic-walled Foraminifera are to be found in brackish and freshwater environments. Agglutinated species build their test using ambient
components but are not commonly regarded as calcifying organisms. An impact of salinity on foraminiferal calcification has been observed in several studies. It seems
that Foraminifera are incapable of constructing a fully calcified test in low salinity regimes; they use sea water not only as a source of ions to construct shell, but also
as a biomineralisation solution. Thus, the success of ostracods in invading freshwater habitats can be attributed to their development of a more effective mechanism
of calcification in low mineralisation waters. The core question of this study is to examine possible causes for the differences in success between the two taxa.

A study was conducted to determine the distribution of ostracods in offshore sediment around Pulau Tinggi, Johor. A total of 11 stations were determined as sampling area. The abundance of ostracods is high in this study area. A total of 1975 specimens were found belonging to 16 family, 36 genera and 51 species. Family Trachyleberididae has the highest diversity of species with 19 species recorded and the most dominant family with 589 specimens. The most dominant species is Loxoconcha malayensis Zhao & Whatley, 1989 with 131 specimens. Several in-situ physico-chemical parameters such as temperature, dissolved oxygen (DO), depth, salinity and pH were measured. The range values for each of these parameters are 26.29-29.02oC, 4.49-6.87 mg/l, 8.30-35.00 m, 34.01-38.90 ppt and 8.11-8.20, respectively. For ex-situ physico-chemical parameters such as percentage of organic matter, sand, clay and silt, the range values for each parameters were 4.91-10.73%, 88.41-97.26%, 0.84-7.49% and 1.89-6.22%, respectively. The sediment texture in this study area can be categorized as fine, medium and coarse sand. The most dominant texture is medium sand. Correlation analysis shows that salinity, the percentages of organic matter, clay and silt are positively and significantly correlated with the abundance of ostracods while temperature and percentage of sand are negatively and significantly correlated with ostracod abundance. Other parameters do not show any significant correlation.

The earliest ostracods from the Bohemian Massif (Central European Variscides) have been recorded from the Middle Ordovician of the Prague Basin (Barrandian area), in the upper Klabava Formation, and became an abundant component of fossil assemblages in the overlying Šárka Formation. Both early ostracod associations consist of eight species in total, representing mainly eridostracans, palaeocopids, and binodicopids. The revision, description, or redescription of all species and their distribution in the basin is provided. Their diversification patterns and palaeogeographical relationships to ostracod assemblages from other regions are discussed.

The material for this research was obtained from 23 stations between spring 1998 and autumn 1998. According to this study, 70 species were determined belonging to 17 family and 32 genera . These 70 species are given below: Polycopa reticulata, Polycopa parareticulata, Polycopa frequens, Polycopa demulderi, Polycopa sp, Cytherella alvearium, Cytherella vandenboldi, Cytherella vulgata, Bairdia mediterranea, Bairdia conformis, Neonesidea crasenticlavula,Leptocythere aff castanea, Leptocythere multipunctata, Leptocythere sp., Calistocythere adriatica, Calistocythere littoralis, Cytheridea neapolitana, Cyprideis torosa, Pontocythere elongata, Pontocythere turbida, Neocytherideis fasciata, Bosquatina carinella, Acantocythereis hiystrix, Carinocythereis carinata, Carinocythereis antiquta, Carinocythereis rhombica, Costa punctatissima, Costa edwardsii, Hiltermanicythere turbida, Pterigocythereis jonesi, Henryhowella sarsii, Echinocythereis laticarina, Echinocythereis keyseri, Aurila oblanga, Aurila convexa, Aurila aff maculosa, Aurila prasina, Aurila sp., Cythereis polygonata, Urocythereis neopolitana, Urocythereis distinguende, Cytheretta adriatica, Loxoconcha napoliana, Loxoconcha ovulata, Loxoconcha tumida, Loxoconcha stellifera, Loxoconcha rhomboidea, Loxoconcha punctatella, Paracytheridea parallia, Semicytherura diafora, Semicytherura ruggieri, Semicytherura inversa, Semicytherura aff. �nversa, Semicytherura mediterranea, Semicytherura rara, Semicytherura sp., Cytherepteron latum, Cytherepteron alatum, Cytherepteron punctatum, Xestoleberis dispar, Xestoleberis communis, Xestoleberis plana, Xestoleberis margaritopsis, Bythocythere turgida, Paradoxostoma rarum, Paradoxostoma smile, Sclerechilus contortus, Pontocypris acuminata, Propontocypris prifera, Propontocypris dispar.

The Laurinswand section in the Rosengarten/Catinaccio Massif (Dolomites, Southern Alps, Italy) covers the Permian-Triassic boundary in a proximal marine setting. The section has been studied for palynology, ostracods and carbonate microfacies. Five microfacies types are defined for the carbonates of the Bellerophon Formation (Changhsingian) in this section. Ostracod assemblages from the upper Bellerophon Formation show a moderate to high diversity and mostly indicate normal marine conditions, with some samples from the upper Casera Razzo Member being dominated by eurytopic forms. The ostracod fauna follows transgressive-regressive trends with low diverse assemblages occurring in the regres-sive parts. These trends are also reflected in the microfacies and can be assigned to three sequences. Palynological assemblages are dominated by phytoclasts, which is typical for proximal marine environments. Sporomorphs are represented predominantly by bisaccate and asaccate pollen grains and are mostly minor components of the palynofacies. Other minor , but consistent components in the Bellerophon Formation are acritarchs, Reduviasporonites and unidentified possible algae or fungi. The latter are particularly abundant in samples with ostracod faunas indicating restricted conditions. The Werfen Formation (uppermost Permian to Lower Triassic) yielded quantitatively poor palynological assemblages, with one sample from the Tesero Member showing a notable increase in spores and spore tetrads. This is indicative of the so-called "spore spike", a well-known signal from this interval. One sample from the overlying Mazzin Member demonstrated a high relative abundance of Reduviasporonites, which may be related to mass occurrences of this taxon in the Tesero Member at Tesero and at other localities near the Permian-Triassic boundary. Such a mass occurrence normally pre-dates the spore spike, whereas at the Laurinswand, the former postdates the latter considerably.

The article presents new results of biostratigraphic and isotopic analyses for the Upper Famennian - Lower Tournaisian deep-water deposits of the Syvyu River section. Ostracode and conodont faunal changes, interpretation of lithological particularities and O and C isotopic variations enabled description of the boundary of the Systems, and identify stratigraphic equivalents of the Hangenberg Shale.

Investigation of the ostracod faunas recovered from two outcrop sections representing the Eocene succession at Wadi Tayiba and Wadi Nukhul in west central Sinai area yielded 47 species and subspecies belonging to 21 genera and 12 families. The ostracod faunal diversity and abundance are fairly high in the middle part of the two sections (Darat and Khaboba Formations), however dramatically decrease in the lower part of the two sections (Thebes Formation) as well as the upper part of the Wadi Tayiba section (Tanka Formation). Biostratigraphic evaluation of the recorded faunas revealed that the recorded assemblage is typically a Middle Eocene assemblage. The early Middle Eocene (Lutetian) and late Middle Eocene (Bartonian) intervals are distinguished by different ostracod species. The recorded ostracod faunas are entirely comprised of marine taxa. They implicate that the studied succession was deposited in marine environment, under inner to middle neritic environmental settings with transient intervals displaying a deeper outer neritic setting.

This study has been performed in the region of Ayvalık (Balıkesir) in August, in 1989. The material collected from ten stations were evaluated and classified. The results are as follows: 2 super families (CYPRIDACEA, CYTHERACEA); 4 families (ILYOCYPRIDIDAE, CYPRIDIDAE, CYPRIDOPSIDAE, CYTHERIDEIDAE); 6 genera (ılyocypris, Cyprinotus, Heterocypris, Cypridopsis, Stenocypris, Cyprideis); 3 species (Heterocypris incongruens, Cyprinotus inaequivalvis Cypridopsis newtoni, Cypridopsis vidua, Ilyocypris bradyi, Ilyocypris gibba, Stenocypris malcolmsoni, Cyprideis torosa.

This study was performed in the Kur;ukr;ekmece lake (Istanbul) in spring,
summer, autumn and winter months. The materials collected from 23 stations were evaluated and 13 species belonging to 10 genera were determined: Ilyocypris biplicata, Ilyocypris bradyi, Ilyocypris decipiens, Candona sp, Eucypris virens, Cyprinotus salinus, Heterocypris incongruens, Herpetocypris chevreuxi, Ilyodromus olivaceus, Cypridopsis parva, Potamocypris yillosa, Cyprideis torosa, Cytheretta adriatica. Of these species C. adriatica is a new species for the Ostracoda fauna of Turkey.

Bu çalışmada Birecik Baraj Gölü Havzası ve Hazar Gölü’nden alınan örnekler değerlendirilmiş; sonucunda, Birecik Baraj Gölü Havzası’ndan 11 tür (Darwinula stevensoni (Brady & Robertson,1870); Candona neglecta Sars, 1887; Candona angulata Müller, 1900; Fabaeformiscandona sp.; Pseudocandona cf albicans; Cryptocandona sp.; Ilyocypris sp.; Heterocypris salina (Brady, 1868); Potamocypris sp.; Limnocythere inopinata (Baird, 1843); Kovalevskiella sp.) ve Hazar Gölü’nden 3 tür (Candona neglecta Sars, 1887; Candona sp.; Limnocythere inopinata (Baird,1843)) bulunmuştur. Bu çalışma ile bildirilen türler Birecik Baraj Gölü Havzası ve Hazar Gölü için ilk kez kayıt edilmektedir.

The study of two Eocene sections exposed at Wadi Nukhul and Wadi Tayiba in west-central Sinai, Egypt for ostracods yielded diverse fauna. Investigation of the recorded taxa revealed findings of eight new marine ostracod species, one belonging to the family Krithidae, Parakrithe tayibaensis n. sp., three to the family Cytheruridae, Cytheropteron bicostsatum n. sp., Cytheropteron nukhulensis n. sp. and Cytheropteron speijeri n. sp., three to the family Trachyleberididae: Digmocythere centroreticulata n. sp. in subfamily Brachycytherinae and Buntonia bassiounii n. sp. and Buntonia posteroacuta n. sp. in subfamily Buntonii-nae, and one, Xestoleberis posterotruncata n. sp., to the family Xestoleberididae. The newly erected species have been described and compared with nearest known and probably related taxa. Their records in the studied sections are stratigraphically confined to the Middle Eocene (Lutetian-Bartonian) interval.

Since ostracods are a species complex in which parthenogens coexist on a regular basis with their sexual ancestors or in which asexual and sexual lineages are known they are good material to understand how genetic variation and clonal diversity are maintained and to study the ecological and evolutionary consequences of parthenogenesis. In
this study, we haye studied three different Ostracoda species, Heterocypris incongruens, Eucypris inflata and Cypridopsis vidua sampled from Omerli Dam and Mahmutlu Brook were established. As a result, it was observed that, Heterocypris incongruens, have 24,
Eucypris inflata have 21 and Cypridopsis vidua have 24 chromosemes,-averag

Results of the study of pelagic ostracods (Halocyprididae) from the western Bransfield Strait are discussed. The data
were obtained using zooplankton samples collected in March 2002 during the 7th Ukrainian Antarctic expedition.
Maximum sampling depths varied from 200 to 1000 m. Eight halocyprid species were found. Three species were
dominant throughout the entire sampling depth: Metaconchoecia isocheira (in the layers 0 – 500 and >500 m it contributed
44 and 31 % respectively to the halocyprid population), Alacia belgicae (28 and 23 %), and Alacia hettacra
(24 and 21 %). The fourth species, Boroecia antipoda, was dominant >500 m (21 %). The other species found were
Metaconchoecia skogsbergi, Proceroecia brachyaskos, Disconchoecia aff. elegans and Conchoecissa symmetrica,
which occurred in small numbers at depths of 200 – 500 and >500 m, and at these depths the abundances and biomasses
of the halocyprids were at their maxima. Few ostracods occurred in the upper 100 m, but their abundances
increased along the frontal zone formed between the water masses advected in from the Bellinghausen and Weddell
Seas. The populations of the ostracod species inhabiting water masses of these two Seas had distinctive age structures.
Key words: pelagic ostracods, Halocyprididae, quantitative distribution, age structure, Bransfield Strait, Antarctica

The post-embryonic development of the appendages of the Cyprididae ostracod Heterocypris salina (Brady, 1868) are described in detail and compared with those of other podocope species documented in previous studies. Generally,
the appearence of limbs during onotgeny of H. salina is similar to that of other species, but small differences in limb morphologies were identified between H. salina and other Cyprididae species, including other Heterocypris species. Some features appear either earlier or later in the development of H. salina compared with other species, even species of the same genus. These features may be useful characters for phylogenetic analyses
at the genus and family levels.
http://link.springer.com/chapter/10.1007%2F978-1-4020-6418-0_19

In this study the material, collected in August 1989 in th vicinty of Bergama
and Ayvalık from Seventecn different station choosen on the basis of Lagoon area was
examined. And two sub-order (Plalycopa-Podocopa); two süçper family (Cytheracea,
Cypridacea); eight familles; (Cytherellidae, Leptocytheridae, Cytherideidae,
Cushmanideidae, Trachyleberididae, Hemicytheridae, Loxoconchidae,
Pontocyrididae); twenty genera (Cytherella alvearium, Cytherella abyssorum,
Leptocythere pellucida, Cyprideis torasa, Pontocythere elongata, Cythereis
dunelmensis, Hiltermanycythere af. Rubra, Aurila convexa, Aurila woodwardi, Aurila
spayeri, Aurila prasina, Urocythereis britannica, Urocythereis distinquenda, Caudites
calceolatus, Loxoconcha exagona, Loxoconcha impressa, Loxoconcha stellifaera,
Loxoconcha bairdi, Loxoconcha parallela, Pontocypris intermedia) were determined.

Data on Mesozoic palynomorphs and ostracods of the Bodrak River Basin (Southwestern Crimea) are
presented. The argillites of the tectonic melange zone contain Toarcian palynomorphs of the Lower Jurassic,
redeposited Triassic spores and pollen; Early Jurassic ostracodes have been identified for the first time. In the
argillite breccia from the base of the volcanic-sedimentary strata, Bajocian spores, pollen, and dinocysts of the
Middle Jurassic have been identified. Based on organofacies analysis of kerogen, an assumption was made about
the conditions of sedimentation.

The South Caspian is one of the largest oil-producing regions within the Caspian Sea. Most of the offshore fields are focused here along with the main geologic oil and gas reserves of Azerbaijan. The development of the discovered fields, prospects and exploration of new ones require detailed study of the Quaternary deposits: their material composition, stratigraphy, thicknesses and other properties. It is necessary to study these issues not only for improvement of the efficiency, provide safe geological prospecting and exploration, but also to solve engineering and geological tasks related to the planned development of discovered oil and gas fields.
Study of fauna and stratigraphy of the Quaternary deposits in the South Caspian is important to learn the Quaternary history of the Caspian Sea. The Quaternary time is known for its frequent and abrupt fluctuations in climate, ocean and sea levels, considerable changes in topography, fauna, flora and other natural components of the Earth. The large-scale well drilling in the South Caspian water area provided geological information particularly about ostracod fauna, stratigraphy and litho-facies features of the Quaternary deposits of the studied regions.
We investigated the systematic composition and distribution regularities of ostracod fauna from the Quaternary deposits over the vast South Caspian territory, including the stratigraphic role of the fauna and correlation of the data with the coastal –onshore area. Multiple well sections and their enclosed micro- and macro fauna were the study target. When we analyzed and correlated well sections and natural outcrops we used other methods like lithological, macro fauna, radiometric, electric logging, seismic logging as well. The result of our study allowed us to design a detailed stratigraphic chart for the Quaternary deposits of the entire South Caspian basin. For the first time the Quaternary deposits of the South Caspian breakdown with 5 supra horizons, 10 horizons with 7 index species. Index species were identified on the successive change of zonal complexes- biozones. All these subdivisions play a regional role and correlated well with the ones from the adjacent areas of the Caspian region.
The paleontological processing of individual ostracod of genera: Leptocythere, Amniocythere, Euxinocythere, others allowed us to identify specific features among them in order to differentiate a new ostracod species.
We also highlighted the issues of stratigraphy, facies analysis and thicknesses of the Quaternary deposits in the South Caspian. The analysis of facies, thicknesses and fauna distribution shows that in the Quaternary time the South Caspian region was characterized by rather dynamic paleogeographic settings: along with the active change of the sea bottom topography, salinity and temperature varied considerably and often, as well as the sea level.

A total of 479 samples from five drill-holes of the Pelotas Basin were analysed. Despite the huge number of samples, only 98 specimens were recovered, belonging to nine families, 21 genera and 34 species (most in open nomenclature). Due to the paucity and poor preservation of this material, just seven taxa were identified or tentatively identified at the species level: Cytherella cf. C. araucana Bertels, Cytherelloidea spirocostata Bertels, Bairdoppilata triangulata Edwards, Actinocythereis indigena Bertels, Brachycythere gr. sapucariensis Krömmelbein, Wichmannella araucana Bertels and Wichmannella meridionalis Bertels. Four taxa could not even be identified at the generic level and are referred as “gen. et sp. indet.”. Trachyleberididae and Cytherellidae were the most diversified and abundant families while Cytherella and Paracypris were the most diversified genera, with seven and four species, respectively. The K–Pg boundary in the Pelotas Basin is marked by a faunal change with the local disappearance of the genera Cytherelloidea, Argilloecia, Cythereis, Brachycythere, Pondoina and Rostrocytheridea, and the first local occurrence of Neonesidea?, Bairdoppilata, Ambocythere, Buntonia, Langiella?, Trachyleberis and Krithe. The genera Cytherella, Paracypris, Wichmannella and Actinocythereis are recorded in the Cretaceous as well as the Paleogene. This faunal study suggests a neritic marine environment for the analysed interval.

Abstract: In this study, the materials collected from 30 stations at different locations at Lake EÛirdir were evaluated. According to the results, a total of 12 species belonging to 11 genera of the superfamilies Darwinulidacea and Cypridacea were determined. Ofthese, Potomocypris variegata (Brady & Norman, 1889) is a new record from Anatolia. At the same time, the parthenogenetic populationsof Plesiocypridopsis newtoni (Brady & Robertson, 1870) are reported from Anatolia in this study for the first time.

This study shows foraminifera and ostracods recovered in a sampling from the Cotinguiba Formation, SergipeAlagoas Basin. The ostracoda microfauna is compound by an abundance of Paracypris eniotmetos (Candonidae) and trachyleberidids (Sergipella? sp., Sapucariella multidifferentis e Sapucariella sp.), besides of taxa Cytherella gambiensis and Cytherelloidea sp., belonging to the Cytherellidae family. The benthic foraminifera association is compound by agglutinant taxa with predominance of the spiroplectamminids (Quasispiroplectammina cf. regoi and Quasispiroplectammina sp.), and taxa with calcareous hyaline shells, represented by gavelinelids and turrinilids (genus Praebulimina), which domain the association. The planktonic foraminifera assemblage is recognized by the frequency of Planoheterohelix ex gr. Globulosa and abundant hedbergenilids, represented by the genus Whiteinella (Whiteinella baltica, Whiteinella cf. baltica, Whiteinella aff. archaeocretacea, Whiteinella? sp.), beside...

The paleontological mass extinction event at the end of Mesozoic (the so-called K-Pg mass extinction)
has generated several, and partly controversial or even sensational hypotheses as to its cause. Podocopida ostracodes,
which are benthic or nektobenthic, were affected in a non-catastrophic mode. Not withstanding, reviewing the
studies on this subject it becomes clear that stratigraphic resolution and taxonomic accuracy exerted a strong
influence on the significance attributed to this event in previous studies. Although in this event no suprageneric
taxon became extinct, as was the case in the Permo-Triassic event, the richness of such genera as Paleocosta
Benson, Hysterocythereis Ceolin and Whatley, Orthrocosta Ceolin and Whatley, Keijia Teeter, Actinocythereis
Puri, and Protocosta Bertels increased in some of the studied K-Pg sections. Some ecological peculiarities are
briefly commented on in an attempt to explain this selective pattern of Podocopida ostracode extinction

Modern global change threatens alpine ecosystems by forcing species to migrate to higher elevations and potentially eliminating alpine habitat altogether. Here we show that an analogous restriction of suitable habitat operates on submarine mountains. During the Paleocene–Eocene Thermal Maximum (PETM, ca. 55.96 Ma), ostracodes underwent local extinction on the crest of Allison Guyot in the central Pacific Ocean, which lost 64% of its ostracode species richness (14 species reduced to three species) and as much as 94% of ostracode abundance for ∼1.1 m.y., before recolonization rebuilt biodiversity and abundance over the next 200 k.y. Biotic changes may reflect an increase in current speeds, acidification, and a decrease in food supply owing to a temperature-driven increase in metabolic rates. Notably, continental margin ostracodes also underwent extinction during the PETM (25%–38% loss) but, unlike Allison Guyot faunas, could quickly repopulate the continental slope. The absence of refugia for isolated seamounts prolonged the reduction in biodiversity initiated by the PETM, a pattern that may be expected for modern seamount faunas in an era of future global change.