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1
CHATTERJEE, TAPAS, IGOR DOVGAL, ROSAURA MAYÉN-ESTRADA y GREGORIO FERNANDEZ-LEBORANS. "A checklist of ciliates (Ciliophora) inhabiting on ostracods (Crustacea, Ostracoda)". Zootaxa 4763, n.º 1 (8 de abril de 2020): 17–30. http://dx.doi.org/10.11646/zootaxa.4763.1.2.
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A compilation of the ciliated species found on freshwater and marine ostracods as epibiont or parasite (endobiont) has been carried out based on published records. The checklist includes the taxonomic position of each species of epibiontic and endobiontic ciliate, the species of basibiont ostracodes, the geographic zones and the bibliographic references where they were recorded. Altogether 7 suctorian, 29 peritrich, one apostome and one scuticociliatid species were listed. Two of recorded suctorian species are possible specific to marine ostracodes, whereas only one, Tokophrya sibirica to freshwater hosts. Fourteen species of peritrichs are likely specific to freshwater ostracodes, while three possible specific to marine ostracode hosts. Other suctorian and peritrich ciliate species were found on a variety of host taxa. One species of scuticociliatid was recorded as endobiont in ostracod.
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Holmes, Jonathan A. "Future Trends and Goals in Ostracode Research". Paleontological Society Papers 9 (noviembre de 2003): 275–90. http://dx.doi.org/10.1017/s1089332600002254.
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In recent decades, research on ostracodes has grown dramatically. While many aspects of the group have been investigated, this review focuses on the paleoenvironmental applications of ostracodes from marine and nonmarine environments. It is argued that while ostracodes have great potential as paleoenvironmental tools, much of that potential has not yet been fully realized because of our imperfect understanding of ostracode biology, taxonomy, systematics and ecology. Future developments will be sure to result from additional studies in these areas, and will also be effected by exchange of ideas with scientists working on related proxies. However, the flow of ideas should not be one-way; workers in other disciplines can also learn from the study of ostracodes.
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Friedman, Gerald M. y Robert F. Lundin. "Freshwater ostracodes from upper Middle Devonian fluvial facies, Catskill Mountains, New York". Journal of Paleontology 72, n.º 3 (mayo de 1998): 485–90. http://dx.doi.org/10.1017/s0022336000024240.
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Leperditiocope ostracodes identified asSollenella? sp. were discovered in the Gilboa Formation (upper Givetian, uppermost Middle Devonian) within the continental Catskill Magnafacies of New York State. The deposits in which the ostracodes were found are meandering-fluvial facies that were part of a vast alluvial plain that sloped westward from the eroding Acadian Mountains. Hence, ostracodes colonized freshwater habitats earlier than heretofore thought. It has been widely accepted that, until now, the oldest known unequivocal occurrences of freshwater ostracodes are of Late Carboniferous age. This new discovery means that the first colonization of freshwater habitats by Ostracoda occurred approximately 60 million years earlier than previously known.
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Yasuhara, Moriaki, Yuanyuan Hong, Skye Yunshu Tian, Wing Ki Chong, Rachel Wai Ching Chu, Hisayo Okahashi, Markus Reuter, Werner E. Piller y Mathias Harzhauser. "Early Miocene marine ostracodes from southwestern India: implications for their biogeography and the closure of the Tethyan Seaway". Journal of Paleontology 94, S80 (agosto de 2020): 1–36. http://dx.doi.org/10.1017/jpa.2020.44.
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AbstractTwenty-six genera and 34 species of early Miocene Indian shallow-marine ostracodes were examined for taxonomy and paleobiogeography. A new genus Paractinocythereis and new species Costa ponticulocarinata were described. Early Miocene Indian ostracode fauna shows strong affinity to Eocene–Miocene Eastern and Western Tethyan ostracode faunas and Miocene–Recent Indo-Pacific ostracode fauna, supporting the Hopping Hotspot Hypothesis that the Tethyan biodiversity hotspot has shifted eastward through Arabia to Indo-Australian Archipelago (IAA) together with concomitant biogeographic shifts of the Tethyan elements. The result also indicated an inverse westward distributional shift in a genus. It is important to note that Paleogene and Miocene shallow marine ostracodes from the IAA region remain poorly investigated, and more fossil ostracode data are needed to better test the Hopping Hotspot Hypothesis.UUID: http://zoobank.org/d1e29249-8c5b-49bf-a47a-5f18e1fc4426
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Ito, Emi, Patrick De Deckker y Stephen M. Eggins. "Ostracodes and Their Shell Chemistry: Implications for Paleohydrologic and Paleoclimatologic Applications". Paleontological Society Papers 9 (noviembre de 2003): 119–52. http://dx.doi.org/10.1017/s1089332600002187.
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The shell chemistry of ostracodes is a useful indicator of past environmental conditions especially when the chemistry data are considered along with other proxy data. The complexities involved with the chemical and isotopic changes accompanying hydrologic change, solute evolution, and the autoecology of ostracodes all point to the need to exercise caution when interpreting shell chemistry. Nevertheless, the stable-isotope values and cation ratios (e.g., Mg/Ca, Sr/Ca) as well as the species assemblage of ostracodes can provide powerful tools for the reconstruction of paleoclimate and paleohydrology. In particular, the changes in Mg/Ca and Sr/Ca of well-calcified ostracodes shells record the qualitative changes in solute composition, and when the dissolved Mg/Ca remains relatively constant, the Mg/Ca in the ostracode shell is proportional to water temperature.
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Sugumaran, S., H. M. Nagaraj y U. B. Mallikarjuna. "Ostracode fauna from the Patti Formation (Late Cretaceous) of Vridhachalam area, Tamil Nadu, India". Journal of Palaeosciences 46, n.º (1-2) (31 de diciembre de 1997): 133–40. http://dx.doi.org/10.54991/jop.1997.1327.
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An ostracode fauna is recorded from the Patti Formation (Late Cretaceous) of Vridhachalam area, Tamil Nadu. The assemblage includes Bairdia pentagonalis, B. cretacea, B. supplanata, Macrocypris limburgensis and Paracypris limburgensis, which are typical of Maestrichtian age. The ostracodes show strong affinities with those recorded from the Ariyalur and Pondicherry areas, and those described from the type-Maestrichtian of Holland. The above assemblage and the presence of distinct Paleocene ostracodes in the overlying Pondicherry Formation throw light on K/T transition in the Vridhachalam area. The paper also discusses the stratigraphic distribution and zoogeographic affinities of the ostracode fauna with equivalent formations in India and the type areas elsewhere.
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Tinn, Oive y Tõnu Meidla. "Ordovician ostracodes from the Komstad Limestone". Bulletin of the Geological Society of Denmark 46 (20 de diciembre de 1999): 25–30. http://dx.doi.org/10.37570/bgsd-1999-46-03.
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The results of a pilot study on late Arenigian ostracodes of Bornholm, Denmark, are reported. The hard thermally altered limestone was disintegrated with sodium hyposulphite, the yielded ostracode material is of satisfactory preservation. The ten identified genera include palaeocopes (Glossomorphites, Aulacopsis, Ctenentoma, Asteusloffia, Euprimites), eridostracans (Conchoprimitia), cytherelliformes (Unisulcopleura) and metacopes (Elliptocyprites, Longiscula, Microcheilinella and “Silenis”). The studied ostracode assemblage shows resemblance to that of the Central Baltoscandian Confacies Belt.
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Cronin, Thomas M. y Gary S. Dwyer. "Deep Sea Ostracodes and Climate Change". Paleontological Society Papers 9 (noviembre de 2003): 247–64. http://dx.doi.org/10.1017/s1089332600002230.
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Ostracodes are bivalved Crustacea whose fossil shells constitute the most abundant and diverse metazoan group preserved in sediment cores from deep and intermediate ocean water depths. The ecology, zoogeography, and shell chemistry of many ostracode taxa makes them useful for paleoceanographic research on topics ranging from deep ocean circulation, bottom-water temperature, ecological response to global climate change and many others. However, the application of ostracodes to the study of climate change has been hampered by a number of factors, including the misconception that they are rare or absent in deep-sea sediments and the lack of taxonomic and zoogeographic data. In recent years studies from the Atlantic, Pacific, and Arctic Oceans show that ostracodes are abundant enough for quantitative assemblage analysis and that the geochemistry of their shells can be a valuable tool for paleotemperature reconstruction. This paper presents practical guidelines for using ostracodes in investigations of climate-driven ocean variability and the ecological and evolutionary impacts of these changes.
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Ayress, Michael A. "Crescenticythere, a new enigmatic ostracode from the Tertiary of New Zealand". Journal of Paleontology 67, n.º 5 (septiembre de 1993): 905–6. http://dx.doi.org/10.1017/s0022336000037197.
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During examination of the large ostracode assemblage collections at the Department of Scientific and Industrial Research, Geology & Geophysics, Lower Hutt, New Zealand, a single specimen of unusual shape was encountered. So unusual is the crescentic outline and infolding of the entire shell periphery that assignment even to a phylum was difficult, and it was only upon scanning electron microscopic study that subcentral muscle scars were clearly observed and these enabled confident identification of the specimen as an ostracode. One specimen is not usually considered sufficient to propose a new taxon; however, in this case there is no doubt that this unique specimen clearly represents a new species, genus, and probably family of Ostracoda. A search for additional specimens from the type unit is underway, but has, as yet, been unsuccessful to find this rare intriguing ostracode. Unlike other unusual ostracodes described from the Southern Hemisphere such as the punciids, this specimen appears to have no similarity with Paleozoic taxa.
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Crasquin, Sylvie, Milan Sudar, Divna Jovanovic y Tea Kolar-Jurkovsek. "Upper Permian ostracode assemblage from the Jadar Block (Vardar zone, NW Serbia)". Annales g?ologiques de la Peninsule balkanique, n.º 71 (2010): 23–35. http://dx.doi.org/10.2298/gabp1071023c.
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Ostracodes from the Changhsingian (latest Permian age) in the uppermost part of the ?Bituminous Limestone? Formation of the Komiric Section in NW Serbia (Jadar Block, Vardar Zone) are described and illustrated. Three new species of ostracodes are introduced: Basslerella jadarensis n. sp., Acratia serbianella n. sp., and Knoxiella vardarensis n. sp. The ostracode assemblage, together with conodonts and foraminifers, is the first record of the youngest Late Permian age microfaunas from Serbia and from the central part of the Balkan Peninsula.
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Curry, B. Brandon. "Linking Ostracodes to Climate and Landscape". Paleontological Society Papers 9 (noviembre de 2003): 223–46. http://dx.doi.org/10.1017/s1089332600002229.
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Climatic effects on aquatic environments are an important factor in the ecology of ostracodes judging from their biogeography especially with respect to moisture balance and ecoregions (vegetation zones). The importance of climate in controlling ostracode distribution is underscored by major ecological changes indicated by co-stratigraphic changes in ostracode and pollen biozones throughout the Quaternary. Climatic interpretation of ostracode records are complicated, however, by several non-climatic factors, including basin shoaling, changes in water chemistry due to abrupt changes in the flux of groundwater, rivers, and streams to lakes and wetlands, and increasingly shortened water residence time in areas where precipitation exceeds evaporation due to erosion by basin overflow.
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Antonietto, Lucas S., Lisa E. Park Boush, Celina A. Suarez, Andrew R. C. Milner y James I. Kirkland. "The ‘Last Hurrah of the Reigning Darwinulocopines’? Ostracoda (Arthropoda, Crustacea) from the Lower Jurassic Moenave Formation, Arizona and Utah, USA". Journal of Paleontology 92, n.º 4 (26 de abril de 2018): 648–60. http://dx.doi.org/10.1017/jpa.2017.150.
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AbstractAn ostracode fauna is described from lacustrine sediments of the Hettangian, Lower Jurassic, Whitmore Point Member of the Moenave Formation. The Moenave is well known for its rich, Late Triassic?–Early Jurassic fossil record, which includes fossil fishes, stromatolites, ostracodes, spinicaudatans, and a diverse ichnofauna of invertebrates and vertebrates. Four ostracode species, all belonging to the suborder Darwinulocopina, were recovered from these sediments:Suchonellina globosa,S. stricta,Whipplella? sp. 1, andW.? sp. 2. The diversity and composition of the Whitmore Point Member ostracode fauna agree with previous interpretations about Lake Dixie and nearby paleoenvironments as shallow lakes inhabited by darwinulocopine species that survived the effects of the Central Atlantic Magmatic Province and the subsequent end-Triassic extinction and quickly recolonized these areas, thanks to asexual reproduction by parthenogenesis. The Lake Dixie region, in its geographical isolation, could represent the last episode of darwinulocopine dominance in nonmarine environments before the Late Jurassic diversification of the cypridocopine/cytherocopine modern ostracodes.
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Tanaka, Gengo. "Paleogeographical and paleoenvironmental significance of ostracodes from the Pennsylvanian Nagaiwa Formation, northeast Japan". Journal of Paleontology 97, S92 (23 de marzo de 2023): 1–33. http://dx.doi.org/10.1017/jpa.2022.108.
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AbstractThe Early Pennsylvanian Nagaiwa Formation contains fossils such as corals, fusulinids, and ostracodes, and its age and depositional environments have been determined by fusulinids and sedimentology. In this study, I describe the ostracode assemblages from the Nagaiwa Formation. Moreover, I provide a reconstruction of the paleogeography of northeastern Japan during the Early Pennsylvanian by comparing this ostracode assemblage with assemblages from other regions during the same period. Thirty ostracode species, including 12 genera, have been identified, most of which are endemic species and 10 of which are new: Jordanites michinokuensis n. sp., Thuringobolbina ikeyai n. sp., Aechmina iwatensis n. sp., Pseudobythocypris asiatica n. sp., P. zipangu n. sp., P. siveteri n. sp., Platyrhomboides tohokuensis n. sp., P. japonica n. sp., Healdia ofunatensis n. sp., and H. rikutyuensis n. sp. Two of these species are also found in central Japan. The ostracodes from the Nagaiwa Formation are unique when compared with any other similarly aged assemblages.UUID: http://zoobank.org/c43f0787-4bb6-45d1-9c12-54a747c0b040
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Baltanás, Angel, Wolfgang Brauneis, Dan L. Danielopol y Johann Linhart. "Morphometric Methods for Applied Ostracodology: Tools for Outline Analysis of Nonmarine Ostracodes". Paleontological Society Papers 9 (noviembre de 2003): 101–18. http://dx.doi.org/10.1017/s1089332600002175.
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Morphometric techniques for the analysis of shape change in organisms have experienced a noteworthy development in the last decade. But despite the significant contributions that ostracodologists made to the field, their use in standard ostracode research is far from common. This contribution stresses the usefulness of morphometric methods to describe ostracode valve outlines and to summarize shape changes cued by environmental factors. Focus is on nonmarine ostracodes which are generally poorly ornamented so that their carapaces offer few landmarks for characterization of morphological change. Out of several alternatives three techniques for shape analysis are applied here: the B-splines method for approximative description of ostracode contours, Elliptic Fourier Analysis (EFA) and a Generalized (Resistant Fit) Procrustes Analysis. B-splines method is presented here for the first time within a biological framework and both its mathematical basis and practical usage are discussed. Additionally a computer program, Morphomatica, developed for performing B-splines analyses of ostracod outlines is briefly documented.Three case studies exemplify here how morphometric analysis might help either to detect environmental influences in ostracode shape or to show how morphological diversity of ostracode valve reflects environmental change. First, morphological variability within a clonal lineage of Heterocypris barbara (Gauthier and Brehm) is shown to be related to environmental variables (mainly temperature) when raised under controlled conditions in the lab. Second, carapace variability at the population level is explored in a widely distributed species (Limnocythere inopinata Baird) sampled from distant localities. Morphometric analyses illustrate how such variability is not related to geographic distance but to environmental conditions. Finally, patterns of temporal change in morphological diversity of a widely distributed ostracode group, the Candoninae, are elucidated by using the B-splines method combined with multivariate statistical analysis.It is concluded that morphometric methods deserve to be included in the methodological toolbox of practicing ostracodologists as they can provide useful information in ecological and paleoecological research.
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Costanzo, Gary V. y Roger L. Kaesler. "Changes in Permian marine ostracode faunas during regression, Florena Shale, northeastern Kansas". Journal of Paleontology 61, n.º 6 (noviembre de 1987): 1204–15. http://dx.doi.org/10.1017/s0022336000029577.
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The Florena Shale (Permian, Wolfcampian) of the Midcontinent of North America was deposited in a restricted marine basin. Shifting environments due to marine regression caused a gradual change in the ostracode fauna. Cluster analysis and ordination by nonmetric multidimensional scaling of data on ostracode relative abundances revealed three ostracode assemblages, each characteristic of a different environment. The Cryptobairdia seminalis assemblage from the lowest Florena Shale is characteristic of deeper water, offshore, marine environments with only minor influx of terrigenous mud. The Amphissites centronotus assemblage found above the C. seminalis assemblage occupied a similar environment, but with greater influx of terrigenous mud and intervals of increased turbidity. The Knightina texana assemblage occurs stratigraphically highest and probably represents a quiet-water, very shallow, nearshore, marine environment. Although protected from strong wave and current activity, the water mass was occasionally turbid.Species diversity of ostracodes is high both at the base of the Florena Shale, which was deposited in the most offshore position, and again at the top of the lower part of the Florena Shale, which was deposited nearer to the shore. In contrast to diversities of assemblages of ostracodes from similar environments in other stratigraphic units, the K. texana assemblage has an anomalously high diversity. This is due in part to time averaging of adjacent ostracode assemblages and a strong taphonomic overprint.
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Lundin, Robert F., Mark Williams y David J. Siveter. "Domatial dimorphism occurs in leperditellid and monotiopleurid ostracodes". Journal of Paleontology 69, n.º 5 (septiembre de 1995): 886–96. http://dx.doi.org/10.1017/s0022336000035551.
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The discovery of domatial dimorphism in the leperditellid ostracode Loculocavata n. gen. and the monotiopleurid Primitiella minima (Harris), and the possibility that Leperditella Ulrich exhibits domatial dimorphism, requires a revision of the concept and/or diagnosis of the Platycopina. Domatial dimorphism is manifested by a special domiciliar space for egg/brood care in females. Domatia are represented by a loculate domiciliar wall or by a more generalized space bounded anteriorly by an interior partition caused by thickening or folding (sulcation) of the shell wall. Domatial dimorphism occurs in morphologically diverse ostracodes as shown by the podocopine Mesocyprideis, kloedenellids, cytherellids, monotiopleurids, the leperditellid Loculocavata n. gen., and by its possible occurrence in Hypotetragona and Leperditella. Changes in the present concept and/or diagnosis of the Platycopina are required to account for the above. Possible classifications range from restricting the Platycopina to holosolenic ostracodes with R/L overlap and domatial dimorphism to including within the Platycopina all groups that exhibit domatial dimorphism. The position of adductor muscle attachment in Loculocavata n. gen. and Primitiella minima (Harris) suggests that L2 may be the external expression of the position of adductor muscle attachment in some ostracodes.
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Kontrovitz, Mervin, Jerry Marie Slack, Nigel R. Ainsworth y Richard D. Burnett. "Color in ostracode shells: taphonomy and paleotemperature interpretation". Paleontological Society Special Publications 6 (1992): 172. http://dx.doi.org/10.1017/s2475262200007322.
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Interpretations of geologic history would be enhanced if taphonomic processes, including color changes in shells, were better known. This study deals with the origins and alteration of post-mortem colors in podocopid ostracodes. Modern shells were subjected to elevated temperatures and pressures in reactor vessels with sediments, simulating some burial conditions. Fossil shells from outcrops and boreholes were heated and treated with solvents, in an attempt to identify the coloring agent(s).Modern marine shells are white to pale yellow (Munsell 5Y 8/1 – 2.5Y 8/4). Upon heating at atmosphere, up to about 650°, they became slightly redder, slightly darker, and less color saturated, but never dark (Munsell “value” less than 5). From 650-850° they became yellower and lighter, and above 850° chalky and more yellow. Shells at elevated temperatures and pressures (T-P) with organic-poor sediments and/or iron compounds developed higher color values and lower chromas; they did not become dark. Thus, modern ostracode shells subjected to elevated T-P changed colors, but alone never attained the dark colors seen in many fossils. Only those heated in matured organic-rich sediment and/or crude oils became dark (dark grays, browns, and blacks), like some fossils. Fossil ostracodes from boreholes in Mesozoic and Cenozoic sedimentary rocks showed downhole color differences similar to those from experiments. That is, the colors of fossils are different in hue, value and chroma in different thermal zones and ostracode color appears to be broadly indicative of thermal history.Fossils near igneous intrusions are dark, while the lowered values and chromas of those in metamorphics also are correlatable with paleotemperatures. Reheated dark fossils lightened at about 375-450°, eventually becoming pale yellow to white, apparently indicating that organic coloring agents were driven off. This, and the fact that modern ostracodes develop dark colors only when heated in organic-rich substances, support the contention that the dark color originates from extrinsic organic materials. Pyritized shells become weak red (Munsell 10R 4/4) upon heating; thus, they can be distinguised from those colored by organics.Therefore, ostracode colors appear to be diagnostic of T-P and present the potential for use in paleotemperature reconstructions. A wide range of fossils, including conodonts, phosphatic brachiopods, scolecodonts, and palynomorphs are known to show recognizable and useful evidence of thermal maturation and it is proposed that ostracodes be added to the list.
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Dojen, Claudia. "Late Silurian and Early Devonian Beyrichioidea from Gondwana and Perigondwanan terranes and their palaeobiogeographical implications". Bulletin de la Société Géologique de France 180, n.º 4 (1 de julio de 2009): 309–15. http://dx.doi.org/10.2113/gssgfbull.180.4.309.
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Abstract The Late Silurian to Early Devonian palaeogeography and the question whether there has been a large and deep Rheic Ocean between Laurussia and Gondwana is still a matter of discussion. It has been assumed in many papers that the Rheic Ocean formed a palaeogeographical barrier and, therefore, Gondwana had no common beyrichioidean ostracode faunas with Laurussia before the Emsian. The appearance of ostracodes (particularly the beyrichioideans) in Gondwana at this time should testify the closure of the Rheic Ocean. Although some palaeogeographic reconstructions consider common ostracodes in Laurussia and the Perigondwanan areas Armorica and Perunica in the Lochkovian, they do not refer to occurrences in Gondwana. However, several publications describe late Silurian to Pragian beyrichioideans from Gondwana and adjoined Terranes (Perigondwana), thus questioning the existence of the Rheic Ocean at this time. This paper aims to summarize the occurrences of common beyrichioidean ostracodes from (Peri-)Gondwana and Laurussia in an attempt to provide a reliable data source for future work. The occurrences of beyrichioideans from North Africa, South America, southeastern Turkey, Ibero-Armorica, and the Ossa Morena Zone (Spain) are reviewed and their ages are partially re-dated through correlation with other faunas. The presented results indicate that shallow marine migration paths must have existed, thus strengthening the arguments against the Rheic Ocean.
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Horne, David J. "Key Events in the Ecological Radiation of the Ostracoda". Paleontological Society Papers 9 (noviembre de 2003): 181–202. http://dx.doi.org/10.1017/s1089332600002205.
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Ostracodes are ecologically diverse at the present day, inhabiting marine, nonmarine and (semi)terrestrial environments. Modern benthic faunas are dominated by Podocopa (marine and nonmarine Podocopida, marine Platycopida, and extremely rare marine Palaeocopida), while the Myodocopa (Myodocopida and Halocyprida) are diverse in the marine pelagic realm, as well as having many nektobenthic taxa. Their excellent fossil record facilitates reconstructions of their phylogenetic relationships and ecological adaptations throughout their Phanerozoic history. The earliest known ostracodes are of Ordovician age, when representatives of the extant orders Podocopida, Platycopida and Palaeocopida were already present, together with (possible) early Myodocopa and extinct orders such as the Leperditicopida. Cambrian bivalved arthropods such as bradoriids and phosphatocopids are no longer regarded as Ostracoda.Ordovician ostracodes were predominantly marine meiobenthos, diversifying into depth-related assemblages dominated by palaeocopids. The beginnings of podocopan radiations in marginal marine environments (brackish and hypersaline waters) are seen in the Silurian, as is an ecological shift of nektobenthic myodocopans to form the first pelagic ostracode faunas. Of the diverse marine Paleozoic palaeocopids, only a single lineage, the puncioids, survived beyond the Permian and today live interstitially in high-energy shallow marine environments. Post-Paleozoic marine benthic ostracode faunas are dominated by cytheroidean podocopids which gave rise to several radiations in the Mesozoic and Cenozoic. The healdiid metacopines (podocopans), of Devonian origins, enjoyed a marine radiation in the Triassic and Early Jurassic and then became extinct. Marine platycopids were also significant components of Mesozoic marine faunas and are relatively diverse in warm, shallow carbonate environments today.Suggestions that the first freshwater ostracodes were Devonian leperditicopids are controversial; undoubted nonmarine / freshwater radiations developed during the Early Carboniferous, including darwinuloidean and carbonitoidean podocopids and possibly some platycopids, together with cytheroidean podocopids (limnocytherids) in the Late Carboniferous. Of these only the darwinuloideans and limnocytherids survived the end-Permian extinctions and are still found in modern nonmarine waters; however, the dominant freshwater ostracodes today are the cypridoidean podocopids, whose radiation began in the Triassic and attained explosive proportions in the Late Jurassic - Early Cretaceous (although there are controversial suggestions of Paleozoic origins for this group). In addition to the limnocytherids there have been several other, separate invasions of nonmarine waters by cytheroidean podocopids, notably the cytherideids and the commensal entocytherids. Radiations in damp terrestrial environments have been initiated by both marine and nonmarine groups, but such invasions lack a recognized fossil record; (semi)terrestrial cypridoideans and darwinuloideans may represent Late Mesozoic radiations, while the Terrestricytheroidea, with marine affinities, may be much older, possibly Late Paleozoic in origin.
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Hoare, R. D. "Ostracodes from the Maxville Limestone (Mississippian, Chesterian) from Ohio". Journal of Paleontology 67, n.º 4 (julio de 1993): 571–85. http://dx.doi.org/10.1017/s0022336000024914.
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A diverse fauna of ostracodes comprising 21 species representing 20 genera are described from the Maxville Limestone in central Ohio. Eight new species are proposed—Roundyella incompta, Deloia spinula, Lokius morsei, Bairdia prolixa, Acratia prolata, Waylandella depresssa, Pseudobythocypris securis, and Paracavellina cooperi.Oliganisus secunda (Croneis and Bristol), Glyptopleura costata (McCoy), and Geffenina praelonga Cooper are represented by tecnomorphs and heteromorphs. Specimens of Sansabella bradfieldi Coryell and Sohn show reversal of valve overlap.The ostracode fauna indicates a Chesterian age for the Maxville Limestone.
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Kovalenko, V. A. "CRITERIA FOR RECOGNIZING THE BOUNDARIES OF STRATIGRAPHIC DIVISIONS OF THE SOUTHERN MEOTIC REGION OF UKRAINE FOR OSTRACODS". Odesa National University Herald. Geography and Geology 28, n.º 1(42) (10 de agosto de 2023): 117–30. http://dx.doi.org/10.18524/2303-9914.2023.1(42).282242.
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Problem Statement and Purpose. Generalized results obtained in the implementation of the state topic IV‑1–18: «justification of the boundaries of regional and local stratigraphic divisions of the Phanerozoic of Ukraine for geological maps of the new generation» are. Criteria for recognizing the boundaries of stratigraphic divisions of the meшotic regioyarus of southern Ukraine by ostracods are established. Ostracod complexes were used to characterize the boundaries of stratigraphic divisions of the meotic region of southern Ukraine: ─ according to the leading species of ostracod (upper meotis ─ lower Pont); ─ by paleoecological characteristics of ostracod species (upper Sarmatian-lower meotis; lower-upper meotis). Data&Methods. Thus, complexes of meiotic ostracods were studied on the Kerch Peninsula: Yanysh-Takyl Mulda (Zavetne village), in the Crimea (Alminskа depression: Well. No. 302 (northern outskirts of Rivnopollye village), in the Black Sea depression: (Berezneguvate village (Mykolaiv region). When stratifying various deposits of the meotic regioyarus, it is very important to know the maximum possibility of practical use of ostracod complexes. Stratigraphic resolution of deposits of the meotic regioyarus of southern Ukraine by ostracod complexes-regiopidyarus, i.e. ostracods allow us to distinguish the lower meotic and upper meotic regiopidyarus. Thus, meotic ostracods allow us to distinguish two ostracod complexes in the lower meotic region-complex No. 1 (lower) and complex No. 2 (middle), and in the upper meotic region-complex No. 3. Results. The border between the upper Sarmatian and lower Meotic regions (complex No. 1 (lower)) is distinguished by paleoecological characteristics of ostracod species: Lower meotic region-complex (complex No. 1 (lower)): as noted earlier (Kovalenko, 2001), study of the species composition of lower meotic ostracods of complex No. 1 (Kerch Peninsula. The southern wing of the Yanysh-Takyl Mulda (Zavetne village)) gave grounds to assert that at that time there was a basin in the studied area that was very close in its bionomic conditions to the Kherson (upper Sarmat) one. The late Sarmatian ostracod fauna inherited by this early meotic Basin did not undergo significant changes, and the late Sarmatian ostracods Loxoconcha rimopora Suzin continued to exist; Euxinocythere suljakensis Suzin; Xestoleberis (Xestoleberis) maeotica Suzin; X. (X.) advena Schneider; X. (X.) goretski Golovko; X. (X.) irregularis Schneider and others. However, the appearance of meotic ostracodes, such as Loxoconcha obsoleta Ljuljev and Euxinocythere retituberculata Suzin, allows us to date these deposits to early meotis. The boundary between the lower meotic (complex No. 2) and upper meotic (complex No. 3) regions is distinguished by the paleoecological characteristics of ostracod species. For the first time for the Kerch Peninsula, the appearance of brackish ostracods of the Pontic type (Second migration wave) (Caspiocypris candida (Livental); Tyrrhenocythere pontica (Livental in Agalarova et al.), juv; Euxinocythere (Maeotocythere) praebacuana (Livental); Loxocorniculina diaffarovi Schneider, Loxoconcha praemitridata Agalarova, Camptocypria acronasuta (Livental). The boundary between the upper meotic (complex No. 3) and lower Pontic (complex No. 1) regions is recognized by the leading ostracod species (appearance of the Pontic type of ostracod fauna-genera Loxocorniculina Krstic, 1972; Camptocypria Zalanyi, 1959; Bacunella Schneider, 1958; Pontoniella Mandelstam, 1956; Caspiocypris Mandelstam, 1956 and others.
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Hawram, Omran A. M. y Hazhar J. Ali. "NEW MIDDLE MIOCENE OSTRACODES (CRUSTACEA) FROM KURDISTAN REGION, NORTHEASTERN IRAQ". Iraqi Geological Journal 51, n.º 2 (31 de diciembre de 2018): 91–123. http://dx.doi.org/10.46717/igj.51.2.6ms-2018-12-28.
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The present paper is focused on new Ostracods species obtained from Fatha Formation (Middle Miocene) in Darbaikhan area, Sulaimani Governorate, Kurdistan province North Eastern of Iraq. Forty-eight Ostracode species belonging to thirty-one genera were described, including eighteen species previously described, twenty-six new species left under open nomenclature because of lack of specimens and/or poor state of preservation.
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Schön, Isa y Koen Martens. "Phylogenetic Reconstructions of Ostracodes – A Molecular Approach". Paleontological Society Papers 9 (noviembre de 2003): 71–88. http://dx.doi.org/10.1017/s1089332600002151.
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Molecular work on ostracodes has thus far either used allozyme-based or DNA-based techniques. The application of allozyme-based methods has provided numerous data on population genetics and reproductive modes in ostracodes. With this technique, it has also been possible to construct phylogenies, although these have been restricted to distance-based methods. With the usage of DNA-based methods, a new era in ostracode research has begun. It is now possible to obtain accurate estimates for genetic diversities at very fine scales, even within individuals. The DNA-based approach is also very useful for reconstructing evolutionary histories at different taxonomic levels. Within species, for example, phylogenies reveal past episodes of dispersal and genetic exchange. Together with morphological data, DNA sequence data can test for congruence of molecular and morphological evolution and variability. At high taxonomic levels, DNA sequence data provide information on mechanisms of evolution and speciation. This allows for testing whether a certain, morphological feature has evolved once or several times independently. By applying the principle of the molecular clock, DNA sequence data provide relative age estimates that can be calibrated against fossil data and be linked to past climatic or geological events.
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Yasuhara, Moriaki y Hisayo Okahashi. "Quaternary deep-sea ostracode taxonomy of Ocean Drilling Program Site 980, eastern North Atlantic Ocean". Journal of Paleontology 88, n.º 4 (julio de 2014): 770–85. http://dx.doi.org/10.1666/13-125.
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Ocean Drilling Program (ODP) Holes 980 B and C, Feni Drift at the eastern slope of the Rockall Plateau, eastern North Atlantic, were examined for late Quaternary deep-sea ostracode taxonomy. Nineteen genera and 32 species were examined and (re-)illustrated with high-resolution scanning electron microscopy images. One new speciesCytheropteron paramassonin. sp. is described and one new nameEucytherura zehaliis proposed forEucytherura hazeliYasuhara et al., 2009. This study provides updated taxonomic information for deep-sea ostracode genera and species from the eastern North Atlantic, which is an important baseline for application of deep-sea ostracodes to paleoceanographical reconstructions and paleoecological studies in this region.
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Hints, Olle, Linda Hints y Kadri Sohar. "Biotic effects of the Ordovician Kinnekulle ash-fall recorded in northern Estonia". Bulletin of the Geological Society of Denmark 50 (30 de abril de 2003): 115–23. http://dx.doi.org/10.37570/bgsd-2003-50-09.
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The Late Ordovician (455 Ma) Kinnekulle volcanic ash-fall represents one of the largest ash eruptions known in Phanerozoic history. The dynamics of ostracodes, polychaete annelids and some shelly macrofauna across the Kinnekulle Bed in the Pääsküla section, northern Estonia indicate some significant faunal changes. The ostracod assemblage underwent major reorganization, including the replacement of predominant forms, a drop in taxon frequency and species diversity, and the probable extinction of some species following the ash-fall. The abrupt response of ostracodes indicates that the sediment surge and the resulting seafloor environment significantly affected the ostracodes. Jaw-bearing polychaetes (as represented by scolecodonts) display changes in their diversity curve and in the abundance of individual species above the altered ash layer. This change occurred after some delay indicating that polychaetes were not affected directly by the sediment influx but indirectly, probably by a change in their relationships with other biotas during a gradual rearrangement of seabed communities triggered by the ash-fall. Macrofaunal data also contains some evidence of the possible direct effects of the ash-fall. Thus, the biotic effects of the Kinnekulle ash-fall were probably larger than previously suggested. Many benthic organisms were strongly affected and the influence of this event persisted some time after the ash-fall.
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Van der Meeren, T., J. E. Almendinger, E. Ito y K. Martens. "The ecology of ostracodes (Ostracoda, Crustacea) in western Mongolia". Hydrobiologia 641, n.º 1 (21 de enero de 2010): 253–73. http://dx.doi.org/10.1007/s10750-010-0089-y.
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Vannier, J. M. C., P. R. Racheboeuf y J. L. Benedetto. "Silurian-Early Devonian ostracodes from South America (Argentina, Bolivia): Preliminary investigations". Journal of Paleontology 69, n.º 4 (julio de 1995): 752–72. http://dx.doi.org/10.1017/s0022336000035265.
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Ostracodes are described from the “Cerro del Fuerte Section” and neighboring localities, all in the Precordillera de San Juan (northern Argentina, San Juan Province), and from sparse faunas in Bolivia (Chuquisaca, Tarabuco Province). Additional material comes from the collection of Thomas (1905). This preliminary study gives the first detailed description of ostracode assemblages in the Upper Silurian and Lower Devonian of the South American continent. Records of other abundant lower Paleozoic (Lower Ordovician to Lower Devonian) ostracodes in Argentina, Bolivia, Brazil, Peru, and Venezuela are also reviewed. Twelve different species, belonging to Palaeocopa (Beyrichiacea and Primitiopsacea) and to Binodicopa and Podocopa (Healdiacea, Thlip-suracea, Cypridacea) are described and a new genus is established (Australobollia n. gen.). Ostracode distribution at Cerro del Fuerte attests to the presence of the Siluro-Devonian boundary within the upper Los Espejos Formation and confirms recent stratigraphical attributions mainly based on conodonts and brachiopods (Benedetto et al., 1992). The beyrichiacean Hemsiella indicates a late Ludlow to Pridolian age for the lower part of upper Los Espejos Formation. The non-palaeocope “Thlipsurella-Phanasymmetria-Ranapeltis” assemblage found in the uppermost part of the formation indicates an Early Devonian (Lochkovian) age. The present study reveals the existence of faunal links at genus (Silurian) and probably species (Early Devonian) level between South America (Argentina, Bolivia), Laurentia, Avalonia-Baltica, and northern Gondwana. For example, close affinities (e.g., Ranapeltis sp. aff. rowlandi and Thlipsurella sp. aff. ellipsoclefta) exist between the uppermost Los Espejos Formation (Argentina) and contemporaneous horizons in the North American Mid-Continent (e.g., Haragan Formation, Oklahoma; Shriver Formation, Pennsylvania). Two types of ostracode assemblages, “beyrichiacean-dominated” and “thlipsuracean-bairdiacean-cypridacean dominated,” are recognized in the Late Silurian–Early Devonian of Argentina and discussed relative to other assemblages known in Laurentia, Avalonia-Baltica, and northern Gondwana. Their paleoecological significance in relation to marine bathymetry is addressed.
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Williams, Mark, James D. Floyd, C. Giles Miller y David J. Siveter. "Scottish Ordovician ostracodes: a review of their palaeoenvironmental, biostratigraphical and palaeobiogeographical significance". Earth and Environmental Science Transactions of the Royal Society of Edinburgh 91, n.º 3-4 (2000): 499–508. http://dx.doi.org/10.1017/s0263593300008348.
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ABSTRACTOstracodes have a wide geographical distribution in the Ordovician of Scotland. They are known from the Southern Uplands, the Girvan district, the Highland Border region and the Inner Hebrides. Overall, more than forty species are recorded. They occur in clastic and carbonate rocks indicative of a range of shallow to deeper marine-shelf environments. Though many of the faunas are allochthonous, broad patterns of ostracode palaeoenvironmental distribution can be elucidated, and elements of the shallow marine Leperditella and open marineshelf Anisocyamus associations (previously recorded from N America) are present. Indigenous faunas are absent from the deep marine sediments of the Southern Uplands Northern Belt. Ostracodes are known from the Arenig, Llanvirn, Caradoc and Ashgill series in Scotland; those of the latter two series have widest biostratigraphical value. In the Girvan district the Caradoc species ‘Ctenobolbina’ ventrospinosa, Krausella variata, Balticella deckeri and Monoceratella teres have correlative value with N America, whilst the Ashgill species Kinnekullea comma appears to be a locum for the anceps graptolite Biozone in Britain, Ireland and possibly the eastern Baltic. The ostracodes are of typical Laurentian affinity, but show progressive generic links with the Baltic region during the late Llanvirn–Caradoc interval, and by Ashgill times display species-level links with southern Britain and Ireland. These distributional patterns suggest approaching geographical proximity for the early Palaeozoic continents of Laurentia, Baltica and Avalonia, and the ability of some Ordovician ostracodes to cross the Iapetus Ocean.
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Sohn, I. G. y A. C. Rocha-Campos. "Late Paleozoic (Gondwanan) ostracodes in the Corumbataí Formation, Paraná Basin, Brazil". Journal of Paleontology 64, n.º 1 (enero de 1990): 116–28. http://dx.doi.org/10.1017/s0022336000042293.
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An abundant, low diversity, poorly preserved Late Permian ostracode faunule was recovered from residues of dissolved limestone. Collections are from the Corumbataí Formation exposed near Conchas, about 194 km northwest of São Paulo and from a borehole into the upper part of the Corumbataí Formation. Although the Corumbataí Formation has been interpreted mainly as a restricted marine-transitional offshore/shoreface and tidal-flat deposit, the ostracodes represent nonmarine taxa. Steinkerns ofCandona, Cypridopsis?, Darwinula?, Gutschickia?, and genus unknown are illustrated in open nomenclature; they indicate freshwater influences. Several Permian marine genera from lower Gondwana (=Carboniferous-Permian), illustrated in open nomenclature, show that their steinkerns would differ from those illustrated here from Brazil. Although the Late Permian drainage from the north into the Paraná Basin has been considered to have been meager, rivers from the north must have supplied sufficient water to freshen the margins of the basin so that immigration of nonmarine ostracodes occurred.Based on the similarity of the distinctive lateral outline of the Brazilian specimens to the nonmarine living genusCandona, the stratigraphic range of the genus is tentatively extended into the Permian.
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Dettman, David L., Alison J. Smith, David K. Rea, Theodore C. Moore y Kyger C. Lohmann. "Glacial Meltwater in Lake Huron during Early Postglacial Time as Inferred from Single-Valve Analysis of Oxygen Isotopes in Ostracodes". Quaternary Research 43, n.º 3 (mayo de 1995): 297–310. http://dx.doi.org/10.1006/qres.1995.1036.
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Abstractδ18O measurements of benthic ostracodes are used to reconstruct the δ18O history of Lake Huron and Georgian Bay water between 10,600 and 7600 14C yr B.P. This δ18O record was calibrated using a comparison of the δ18O values of modern ostracodes and Lake Huron water, where a fractionation of 1.0358 was measured between the oxygen isotope ratios of the most isotopically positive ostracode Candona subtriangulata and lake water. The most positive shell δ18O value was used because it is precipitated in the cold (0° to 2°C) water common to both deep and shallow environments. The δ18O of Lake Huron water reflects a large glacial meltwater component for much of its history before 7600 14C yr B.P. Times of low lake level correlate with the highest ratio of glacial meltwater to local precipitation in the basin (most negative δ18O values). Georgian Bay water was more negative in δ18O than Lake Huron water of the same age; this reflects a higher proportion of glacial meltwater in Georgian Bay and its separation from Lake Huron during times of low lake level.
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Carreño, Ana Luisa y Thomas M. Cronin. "Middle Eocene Ostracoda from Baja California Sur, Mexico". Journal of Micropalaeontology 12, n.º 2 (1 de diciembre de 1993): 141–53. http://dx.doi.org/10.1144/jm.12.2.141.
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Abstract. One genus and six new species of ostracodes are described from the Bateque Formation on the Pacific Coast of Baja California Sur, Mexico. Planktonic foraminifers indicate a mid Eocene age and the whole assemblage is characteristic of a shallow warm-water environment. Paijenborchella mezquitalensis sp. nov. is the second record of the genus Paijenborchella from the Eocene of North America. Except for this species and the new genus Bajacythere, the ostracode association has strong affinities with those described from the lower Tertiary Gulf Coast region.
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Rundic, Ljupko. "Late miocene ostracodes of Serbia: Morphologic and palaeoenvironmental considerations". Annales g?ologiques de la Peninsule balkanique, n.º 67 (2006): 89–100. http://dx.doi.org/10.2298/gabp0667089r.
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About 11.5 million years ago, a tectonic uplift of the Eastern and Western Carpathians separated the Pannonian Basin from the rest of the Paratethys. This orogenesis event caused an unconformity between the Sarmatian brackish sediments and the Pannonian lake-sea deposits. More than 6 Ma later, in these parts of the Paratethys, changes in the geographic framework, hydrological conditions and brackish - caspibrackish water chemistry led to the disappearance of restricted marine forms of life. A few euryhaline and marginal marine species survived this environmental change. Among the ostracodes, some originally freshwater taxa, such as Candoninae, entered the lake-sea. Many lineages show gradual morphological changes. The older, low diversity ostracode fauna from the Lower Pannonian dispersed to the endemic species and genera during the Upper Pannonian. This interval is assigned as the "bloom time" for many ostracodes, both qualitatively and quantitatively. This time sequence is the last appearances of genera such as Aurila Cytheridea, Propontoniella, etc. and simultaneously, the first appearances for many new genera, such as Zalanyiella, Serbiella, Camptocypria Sinegubiella etc. During the Pontian, migration processes were present. Therefore, it can be supposed that many eastern Paratethyan forms have Pannonian origin.
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Morais, Anderson L. M. de y João C. Coimbra. "On a new genus and species of Hemicytheridae (Ostracoda, Crustacea) from the southern Brazilian coast". Iheringia. Série Zoologia 104, n.º 3 (septiembre de 2014): 367–72. http://dx.doi.org/10.1590/1678-476620141043367372.
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This study is based on 62 samples of phytal and bottom sediments collected along rocky beaches (< 3 m water depth) of the central and northern coasts of the state of Santa Catarina (26º10'/27º50'S – 48º26'/48º40'W), southern Brazil. Living and dead ostracodes distributed among 16 families were recovered. In this paper is emphasized one new hemicytherid genus and species that is described and richly illustrated: Auricythere sublitoralis gen. nov. and sp. nov. Some ecological and zoogeographical aspects of this new ostracode are briefly discussed.
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Yamaguchi, Tatsuhiko. "Valve calcification in the evolutionary history of marine ostracodes (Ostracoda)". Journal of Crustacean Biology 39, n.º 3 (4 de enero de 2019): 253–60. http://dx.doi.org/10.1093/jcbiol/ruy086.
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KORNICKER, LOUIS S., THOMAS M. ILIFFE y ELIZABETH HARRISON-NELSON. "Ostracoda (Myodocopa) from Anchialine Caves and Ocean Blue Holes". Zootaxa 1565, n.º 1 (31 de agosto de 2007): 1–151. http://dx.doi.org/10.11646/zootaxa.1565.1.1.
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Eleven stygobitic myodocopid ostracodes (two new–Danielopolina palmeri and Spelaeoecia hox) in the Order Halocyprida are reported from anchialine waters in 11 inland blue holes in Bahamas. One stygobitic halocyprid ostracode is reported from two localities in Bermuda, and one from a cave in Mexico. A new subfamily, Spelaeoeciinae, is proposed to contain the genus Spelaeoecia, and the subfamily Deeveyinae is elevated to family status. Two new species of cladocopid ostracode (Pseudopolycope helix and Pontopolycope storthynx), are described from a cave in Mexico and an oceanic blue hole in the Bahamas. Nine species of myodocopid ostracodes (four new—Rutiderma flex, Eusarsiella syrinx, Eusarsiella fax, and Synasterope matrix) in the Suborder Myodocopina and one species in the Suborder Halocypridina are reported from ocean blue holes in the Bahamas. This is the first report of a halocyprid living in both an inland and ocean blue hole in the Bahamas. The sarsiellid genus Dantya Kornicker & Cohen 1978 is reported for the first time in the Bahamas, but the single juvenile specimen is left in open nomenclature as Dantya sp. A. The development of Deeveya bransoni and Eusarsiella syrinx is described in detail. With the exception of one species of Danielopolina from deep waters of the South Atlantic, all other species of Danielopolina, Spelaeoecia and Deeveya have been previously found only in inland, anchialine caves. The discovery of Deeveya inhabiting deeper, hydrologically-isolated waters in ocean blue holes, which are otherwise comparable to classical anchialine environments, has raised questions concerning the geographic limits to the anchialine habitat and its supposed reliance on terrestrial inputs.
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PINTO, IRAJÁ DAMIANI y IVONE PURPER. "A Devonian Ostracode From Ponta Grossa Formation; Paraná Basin; Brazil". Pesquisas em Geociências 18, n.º 18 (31 de diciembre de 1986): 31. http://dx.doi.org/10.22456/1807-9806.21707.
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Puckett, T. Markham. "Paleogeographic significance of muscle scars in global populations of Late Cretaceous ostracodes". Micropaleontology 58, n.º 3 (2012): 259–71. http://dx.doi.org/10.47894/mpal.58.3.03.
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Ostracodes are among the most useful groups of fossils for applications in paleogeography and plate tectonics, mainly because of their provincial distributions. Analyses by many workers of the distributions of some groups of ostracodes, typically cytherocopine taxa at the generic level, demonstrate that shallow marine ostracode faunas may differ markedly in coeval deposits, even within short geographic distances. These analyses indicate that many shallow marine taxa are unable to cross deep water barriers. An intimate relationship exists, therefore, between plate tectonics and biological evolution. This relationship can reveal clues not only about evolving plate tectonic configurations, but also about the phylogenetic relationships among taxa and the resulting taxonomy. This study focuses on Late Cretaceous shallow marine ostracode genera. Whereas many of these genera are restricted paleogeographically, several, for example Brachycythere, Veenia, Curfsina, Mosaeleberis and Aysegulina (known formerly as Limburgina; see Özdikmen (2010)) among others, are reported to occur on widely separated continents in spite of widely recognized faunal barriers. Brachycythere and Curfsina have been described from such widely separate localities as North America, Europe, India and Australia; yet despite their external similarity, the muscle scar patterns from each geographic region show systematic differences. Although soft parts are rarely preserved, the muscle scar pattern is determined by the configuration of the soft part morphology and is thus of great phylogenetic and taxonomic value. These geographic and phylogenetic patterns indicate at least two possibilities: either there was convergent evolution of the exterior morphology or the exterior morphology is a plesiomorphic state, whereas the muscle scar patterns are apomorphic. In either case, recognition of these clades as discrete taxa contributes to their usefulness in paleogeographic and plate tectonic studies.
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Bhatia, S. B. "Early Devonian ostracodes". Nature 341, n.º 6237 (septiembre de 1989): 15. http://dx.doi.org/10.1038/341015a0.
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Sudar, Milan, Yanlong Chen, Tea Kolar-Jurkovsek, Bogdan Jurkovsek, Divna Jovanovic y Marie-Beatrice Forel. "Lower triassic (Olenekian) microfauna from Jadar block (Gucevo mt., Nw serbia)". Annales g?ologiques de la Peninsule balkanique, n.º 75 (2014): 1–15. http://dx.doi.org/10.2298/gabp1475001s.
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Systematic study of microfossil associations on the Krivi Potok section (Gucevo Mt. area, NW Serbia) has been carried out to document and to refine the Lower Triassic stratigraphic correlations within Alpine-Mediterranean domain. Field investigation and laboratory process have enabled the identification of lowermost Olenekian (lower Smithian) conodonts, ostracodes and pyrite framboids. Two conodont zones are established in this region, in ascending order they are: Pachycladina obliqua-Foliella gardenae Assemblage Zone and Neospathodus planus Zone. A new ostracode species Paracypris ? krivipotokensis FOREL n. sp. has been described, it co-occurs with conodont Neospathodus planus within the Zone of the same name. The pyrite framboids were formed within the ostracode carapaces after their death. The size distribution of pyrite framboids supports the former suggestion that large size (>6 ?m in diameter) is not suitable for the reconstruction of seawater redox conditions.
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Breckenridge, Andy y Thomas C. Johnson. "Paleohydrology of the upper Laurentian Great Lakes from the late glacial to early Holocene". Quaternary Research 71, n.º 3 (mayo de 2009): 397–408. http://dx.doi.org/10.1016/j.yqres.2009.01.003.
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AbstractBetween 10,500 and 9000 cal yr BP, δ18O values of benthic ostracodes within glaciolacustrine varves from Lake Superior range from − 18 to − 22‰ PDB. In contrast, coeval ostracode and bivalve records from the Lake Huron and Lake Michigan basins are characterized by extreme δ18O variations, ranging from values that reflect a source that is primarily glacial (∼ − 20‰ PDB) to much higher values characteristic of a regional meteoric source (∼ − 5‰ PDB). Re-evaluated age models for the Huron and Michigan records yield a more consistent δ18O stratigraphy. The striking feature of these records is a sharp drop in δ18O values between 9400 and 9000 cal yr BP. In the Huron basin, this low δ18O excursion was ascribed to the late Stanley lowstand, and in the Lake Michigan basin to Lake Agassiz flooding. Catastrophic flooding from Lake Agassiz is likely, but a second possibility is that the low δ18O excursion records the switching of overflow from the Lake Superior basin from an undocumented northern outlet back into the Great Lakes basin. Quantifying freshwater fluxes for this system remains difficult because the benthic ostracodes in the glaciolacustrine varves of Lake Superior and Lake Agassiz may not record the average δ18O value of surface water.
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Hunt, Gene, M. João Fernandes Martins, T. Markham Puckett, Rowan Lockwood, John P. Swaddle, Christine M. S. Hall y James Stedman. "Sexual dimorphism and sexual selection in cytheroidean ostracodes from the Late Cretaceous of the U.S. Coastal Plain". Paleobiology 43, n.º 4 (22 de agosto de 2017): 620–41. http://dx.doi.org/10.1017/pab.2017.19.
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AbstractSexual dimorphism is common in many extant animals, but it is difficult to demonstrate in fossil species. Working with material from the Late Cretaceous of the U.S. Coastal Plain, we herein analyze sexual dimorphism in ostracodes from the superfamily Cytheroidea, a group whose extant members have males that are relatively more elongate than females. We digitized outlines of more than 6000 individual ostracode valves or carapaces, extracted size (area) and shape (length-to-height ratio) information, and used finite mixture models to assess hypotheses of sexual dimorphism. Male and female clusters can be discerned in nearly all populations with sufficient data, resulting in estimates of size and shape dimorphism for 142 populations across 106 species; an additional nine samples are interpreted to consist only of females. Dimorphism patterns varied across taxa, especially for body size: males range from 30% larger to 20% smaller than females. Magnitudes of sexual dimorphism are generally stable within species across time and space; we can demonstrate substantial evolutionary changes in dimorphism in only one species,Haplocytheridea renfroensis. Several lines of evidence indicate that patterns of sexual dimorphism in these ostracodes reflect male investment in reproduction, suggesting that this study system has the potential to capture variation in sexual selection through the fossil record.
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Sayar, Cazibe y Roger Schallreuter. "Ordovician ostracodes from Turkey". Neues Jahrbuch für Geologie und Paläontologie - Monatshefte 1989, n.º 4 (1 de abril de 1989): 233–42. http://dx.doi.org/10.1127/njgpm/1989/1989/233.
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Sharpe, Saxon E. y Jordon Bright. "A high-elevation MIS 5 hydrologic record using mollusks and ostracodes from Snowmass Village, Colorado, USA". Quaternary Research 82, n.º 3 (noviembre de 2014): 604–17. http://dx.doi.org/10.1016/j.yqres.2014.01.014.
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AbstractSediments containing terrestrial and aquatic mollusks and ostracodes from the Ziegler Reservoir fossil site (2705 m elevation) near Snowmass Village, Colorado, span ~130–87 ka (MIS 5e through 5b). The southeastern area of the site where taxa were recovered was a relatively fresh, shallow, well-vegetated wetland during MIS 5e through 5c time, approximately 2 m deep, with a total dissolved solids value of ~200–1000 mg L− 1. The wetland was seasonally or annually variable and groundwater discharged along the margins of the bounding moraine. Groundwater likely contributed solutes to the system and may have contributed 18O-enriched water. Based on stable isotopes from ostracode calcite (δ18OOST and δ13COST), seasonal evaporation occurred and the dissolved inorganic carbon pool was unexpectedly enriched in 13C. The mollusk and ostracode faunas changed little across the MIS 5e/5d/5c boundaries, whereas a distinct change in the ostracode fauna occurred between the deposition of Unit 11 and Unit 13, which corresponds in time to the MIS 5c/5b boundary, indicating some combination of increased surface and/or groundwater flow, a decrease in water temperature, and a freshening and a possible deepening of the wetland.
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Coimbra, João C., Ana L. Carreño, Eduardo A. Geraque y Beatriz B. Eichler. "Ostracodes (Crustacea) from Cananéia-Iguape estuarine/lagoon system and geographical distribution of the mixohaline assemblages in southern and southeastern Brazil". Iheringia. Série Zoologia 97, n.º 3 (30 de septiembre de 2007): 273–79. http://dx.doi.org/10.1590/s0073-47212007000300010.
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The ostracode assemblages from Cananéia-Iguape estuarine/lagoon system (southernmost State of São Paulo) are here discussed in detail for the first time. Thirty-four sites, approximately 1 km equidistant, were sampled along the system, including the Cananéia Sea, Pequeno Sea, Cubatão Sea, Ribeira de Iguape River and Itapitangui River. The ostracodes throughout this area have poor assemblages, with a total of 662 specimens of dead and living organisms. The majority of the ostracode fauna is composed of euryhaline species, as follows: Cyprideis multidentata Hartmann, 1955 (174 specimens), Minicythere heinii Ornellas, 1974 (54 specimens), Tanella gracilis Kingma, 1948 (96 specimens) and Whatleyella sanguinettiae Coimbra, Carreño & Ferron, 1994 (226 specimens). Although there are few studies on the Brazilian mixohaline ostracode faunas, including the euryhaline marginal marine taxa, the published data show that the group is best known in the south and southeast regions. Based on this review and with the new data presented in this paper, the geographical distribution of eight mixohaline key species in southern and southeastern Brazil is also discussed.
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Yasuhara, Moriaki, Maria Grimm, Simone N. Brandão, Anna Jöst, Hisayo Okahashi, Hokuto Iwatani, Alexandra Ostmann y Pedro Martínez Arbizu. "Deep-sea Benthic Ostracodes from Multiple Core and Epibenthic Sledge Samples in Icelandic Waters". Polish Polar Research 35, n.º 2 (29 de julio de 2014): 341–60. http://dx.doi.org/10.2478/popore-2014-0001.
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AbstractDeep-sea benthic Ostracoda (Crustacea) in Icelandic waters are poorly known. Here we report deep-sea ostracode assemblages from the multiple core (MUC) and the epibenthic sledge (EBS) samples collected from Icelandic waters by the first cruise of the IceAGE (Icelandic Marine Animals: Genetics and Ecology) project. Samples from shelf-edge and lower-bathyal working areas are examined. The results show (1) distinct MUC and EBS faunas due to the large difference in mesh size of MUC and EBS; and (2) distinct shelf-edge and lower-bathyal ostracode faunas. Such remarkable faunal turnover from shelf to bathyal depths is similar to the faunal turnovers reported from depth transects in the adjacent regions of the western North Atlantic Ocean, the Greenland Sea, and the North Sea, but, at the same time, there are certain differences in the faunal composition between the Icelandic waters and these adjacent regions. In addition, we illustrate many Icelandic deep-sea ostracode species with high-resolution scanning electron microscopy and composite all-in-focus stereomicroscopic images for the first time. These results provide important basic information on deep-sea ostracode research and biogeography of this important region connecting North Atlantic proper and Nordic Seas.
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Vannier, Jean, Shang Qi Wang y Michel Coen. "Leperditicopid arthropods (Ordovician-Late Devonian): Functional morphology and ecological range". Journal of Paleontology 75, n.º 1 (enero de 2001): 75–95. http://dx.doi.org/10.1017/s0022336000031929.
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The functional morphology and autecology of leperditicopid arthropods (Ordovician-uppermost Devonian) are analyzed in the light of well-preserved specimens from the Devonian of China and detailed comparisons with recent ostracodes. Leperditicopids were large, bivalved arthropods (adults ranging from 5 to about 50 mm in length) typically with an asymmetric carapace (strong ventral overlap), a complex muscular system (powerful adductors, extrinsic muscles, tendinous structures) whose insertions are preserved as scars on the inner surface of the exoskeleton and steinkerns, and an extensive radiating network of integumental sinuses probably involved in gaseous and ionic exchanges (oxygen uptake and transport, osmoregulation). The conspicuous chevron scars adjacent to the adductor scars are interpreted as the anchoring spots of mandibular tendinous structures possibly involved in the opening mechanism of the valves. The ultrastructure of the carapace is comparable to that of thick-shelled recent myodocopid ostracodes. A review of leperditicopid occurences (depositional environment, associated faunas and floras) shows that the group preferentially occupied very shallow marginal habitats (tidal flats, reef-flats, lagoons, embayments, or estuarian complexes) that were subjected to environmental stress (salinity, temperature, moisture). This ecological range implies specific adaptations (osmoregulation, resistance to desiccation) supported by morphological evidence (e.g., circulatory system, carapace closing system, thick shell). Most leperditicopids had epibenthic lifestyles and were probably detritus feeders. They may have been adapted (powerful mandibles) to scrape food on algal/microbial mats. Their typical pattern of occurrence (monospecificity, large numerical abundance) displays some of the characteristics of opportunistic populations (e.g., recent ostracodes, branchiopods) living in variable environments. Morphological similarities with Ostracoda are important (e.g., muscular and tendinous features, circulatory system, valve overlap, carapace ultrastructure) but taxonomic relationships with that group remain inconclusive because of the lack of evidence from soft parts.
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Puckett, T. Markham. "Santonian-Maastrichtian planktonic foraminiferal and ostracode biostratigraphy of the northern Gulf Coastal Plain, USA". Stratigraphy 2, n.º 2 (2005): 117–46. http://dx.doi.org/10.29041/strat.02.2.02.
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The Santonian-Maastrichtian deposits of the northern Gulf Coastal Plain of the United States (Mississippi-Alabama) are richly fossiliferous and structurally uncomplicated, offering an excellent setting in which to study calcareous microfossil biostratigraphy. Eight planktonic foraminiferal zones and seven ostracode zones are recognized in these strata, based on the stratigraphic occurrence of 45 species of planktonic foraminifera and 112 taxa of ostracodes. The planktonic foraminiferal zonation is based on standard global biozones. These include the Dicarinella asymetrica Taxon Range Zone, the Globotruncanita elevata Interval Zone, the Globotruncana ventricosa Interval Zone, the Globotruncanita calcarata Taxon Range Zone, the Globotruncanella havanensis Interval Zone, the Globotruncana aegyptiaca Interval Zone, the Gansserina gansseri Interval Zone, and the Contusotruncana contusa-Racemiguembelina fructicosa Interval Zone. Three new ostracode zones are defined, and the upper boundary of two previously defined zones are amended. These zones are the Veenia quadrialira Interval Zone (amended), the Acuminobrachycythere acuminata Interval Zone (new), the Brachycythere pyriforma Interval Zone (new), the Ascetoleberis plummeri Taxon Range Zone (amended), the Curfsina communis Interval Zone (new), the Escharacytheridea pinochii Interval Zone, and the Platycosta lixula Interval Zone. The planktonic foraminiferal biostratigraphy indicates that the age of these deposits range from early Santonian to early Maastrichtian. The Santonian-Campanian boundary is recognized on the basis of the highest occurrence surface of Dicarinella asymetrica, and demonstrates that the contact between the Tombigbee Sand Member of the Eutaw Formation and the Mooreville Chalk is diachronous. The Campanian-Maastrichtian boundary cannot be defined by calcareous microfossils due to the lack of a proxy for the newly established definition. The high-resolution biostratigraphy of the ostracodes, which are indigenous to the North American Coastal Plain, will enable subsequent studies of Late Cretaceous paleobiogeography and Gulf of Mexico-Caribbean tectonic development to be conducted.
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Sobolev, D. B. "Ostracodes from the Devonian-Carboniferous boundary deposits on the reference section Yjid-Kamenka river (Pechora Uplift)". Vestnik of Geosciences 12 (2020): 4–25. http://dx.doi.org/10.19110/geov.2020.12.1.
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This article presents new data on ostracodes and their stratigraphic distribution in the boundary deposits of the Devonian and Carboniferous (D3-C1) in the reference section Kamenka River (Pechora Uplift). The positions of the Kamenka River section and stratotypic sections of the southern Urals relative to the transgressive-regressive sequence are considered. The ostracode assemblage of the Ps. venulosa — Cor. alba — Cr. primaris zone, which occurs in the section on the Kamenka River and appears in sections of the southern Urals from the base of this zone, is represented by the following taxa: Pseudoleperditia venulosa (Kummerov), Coryellina alba Kotschetkova, Bairdia zaninae Posner, Blessites feluyensis Tschigova, Shishaella alekseevae Tschigova, Knoxiella complanata (Kummerov), Cavellina subeichwaldi Buschmina. The taxonomic characteristics of the upper part of the Pseudoleperditia venulosa — Coryellina alba — Cribroconcha primaris ostracode zone (Gumerovian Regional Substage (Horizon)) are supplemented Acratia subordinaria Buschmina, Healdianella ex gr. alba Lethiers, Phlyctiscapha ? pusilla Gurevitsсh, Pustulobairdia ex gr. confragosa (S. et Sm.), Acanthoscapha pechorica Sobolev, Acratina romboiformis Sobolev, and Rectobairdia eleganta Sobolev first appear at this level A gradual and insignificant change in the ostracode association is observed during the transition from the Gumerovian Horizon to the Malevkian Horizon, which precludes drawing the boundary between them. It is suggested that it would have been more appropriate to draw the boundary at the base of the global Hangenberg transgressive event near the base of the Ps. venulosa — Cor. alba — Cr. primaris ostracode zone (South Urals), which coincides with the initial phase of this transgression.
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Bergue, Cristianini Trescastro. "Agulhas e pincéis: as relações entre a paleontologia e a neontologia no estudo dos ostracodes (Crustacea: Ostracoda)". Terrae Didatica 6, n.º 1 (30 de junio de 2015): 9. http://dx.doi.org/10.20396/td.v6i1.8637479.
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O estudo dos ostracodes se desenvolveu sob diferentes influências, sendo possível identificar em sua história tendências orientadas pelas tecnologias de amostragem, a necessidade de conhecimentos aplicáveis à indústria do petróleo e pelo aprimoramento da microscopia óptica e eletrônica. O início da ostracodologia pode ser situado na segunda metade do século XVIII com o estudo de faunas continentais por zoólogos europeus. A pesquisa paleontológica iniciou-se quando as primeiras espécies fósseis foram descritas no início do século XIX. O aprimoramento do conhecimento paleontológico revelou a potencialidade paleoambiental e bioestratigráfica da ostracodologia, tornando-a um importante ramo da pesquisa micropaleontológica. A partir de então, um número crescente de pesquisadores passou a dedicar-se ao estudo destes crustáceos em diversas instituições do mundo, tanto em âmbito acadêmico quanto aplicado à indústria do petróleo. Atualmente, há uma tendência de recrudescimento da pesquisa em ostracodes recentes sob os mais diferentes enfoques. Os novos conhecimentos paleontológicos e neontológicos fornecidos por ela permitirão conhecer melhor a história evolutiva dos ostracodes e de outros artrópodes.
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Rodrigues, Gislaine Bertoglio y Gerson Fauth. "Isótopos estáveis de carbono e oxigênio em ostracodes do Cretáceo: metodologias, aplicações e desafios". Terrae Didatica 9, n.º 1 (25 de junio de 2015): 34. http://dx.doi.org/10.20396/td.v9i1.8637408.
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Ostracodes são microfósseis carbonáticos que têm se destacado na pesquisa de isótopos estáveis devido à rápida calcificação da carapaça, sua elevada sensibilidade aos parâmetros ambientais e à sua ocorrência em diferentes ambientes aquáticos. Os isótopos de carbono proporcionam informações sobre paleoprodutividade e disponibilidade de nutrientes dos oceanos e lagos. Os isótopos de oxigênio são utilizados para estimar a paleotemperatura e a paleosalinidade vigentes em determinada bacia sedimentar ao longo do tempo geológico. Até o momento, as análises isotópicas em carapaças de ostracodes são realizadas principalmente em material do Cenozoico, com poucas pesquisas realizadas para o Mesozoico. Esta técnica é amplamente utilizada em ostracodes de ambientes não-marinhos, sendo realizada com cautela em ambientes transicionais e marinhos, onde a composição da carapaça será semelhante à da rocha carbonática que o contém. Este texto compreende conceitos de isótopos estáveis, da técnica analítica utilizada, da realização das análises em ostracodes e da interpretação dos resultados nos estudos paleoambientais, e propõe um protocolo de pesquisa considerando as dificuldades de amostragem e de aplicação em carapaças do Cretáceo.