Journal of Nannoplankton Research最新文献

{"title":"Nannosys.","authors":"A. Romein","doi":"10.58998/nina2211","DOIUrl":"https://doi.org/10.58998/nina2211","url":null,"abstract":"","PeriodicalId":186533,"journal":{"name":"Journal of Nannoplankton Research","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117035519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Searching for cells: the potential of fossil coccospheres in coccolithophore research.","authors":"P. Bown, S. Gibbs, R. Sheward, S. O’Dea, D. Higgins","doi":"10.58998/jnr2035","DOIUrl":"https://doi.org/10.58998/jnr2035","url":null,"abstract":"The majority of fossil coccolithophore studies are based on disaggregated coccoliths but preserved complete coccospheres provide documentation of true cellular traits (cell size, numbers of coccoliths per cell and calcite quotas) and represent a relatively untapped archive of palaeobiological information. Coccospheres are more frequently present when coccolith preservation is good or exceptional. Their preservation is dependent on a variety of taphonomic factors that combine to minimize the destructive effects of grazing and sinking, seafloor bioturbation and, finally, carbonate diagenesis. Clay-rich hemipelagic sediments that have not been deeply buried are particularly productive. Herein, we highlight the occurrences and potential of these coccosphere fossils and illustrate the range of morphologies we have so far encountered, predominantly from the Paleogene interval. Our observations show that coccosphere morphology is generally a conservative, long-lived character, with fossil representatives of living taxa (e.g., Braarudosphaera, Coccolithus, Helicosphaera, Reticulofenestra), all showing very similar coccosphere style back through their evolutionary history. In addition, we have also observed a variety of sphere shapes (ovoid, ellipsoidal, cylindrical) and significant coccolith polymorphism and varimorphism across a number of different families and in taxa for which fossil coccospheres have not previously been known. Fossil Acanthoica and Calciosolenia spheres, for example, indicate that polymorphism is a long-lived characteristic of the Syracosphaerales group. Lastly, by combining morphometric data from both fossil and living populations we show that coccosphere geometries (coccosphere size, number of coccoliths per coccosphere and coccolith size) show systematic trends (e.g., larger cells have larger coccoliths) but there is significant divergence from this trend that reflects intrinsic, taxon-specific factors (e.g., coccolith shapes and packing) and growth phase of the population. Although our preliminary coccosphere studies have uncovered new, surprising and useful observations we are still far from understanding the fundamental controls on cell size, coccosphere geometry and architecture.","PeriodicalId":186533,"journal":{"name":"Journal of Nannoplankton Research","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115019453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prae-Jurassic and Jurassic calcareous nannofossil bibliography: An update.","authors":"E. Erba","doi":"10.58998/nina2083","DOIUrl":"https://doi.org/10.58998/nina2083","url":null,"abstract":"","PeriodicalId":186533,"journal":{"name":"Journal of Nannoplankton Research","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125446610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"International Nannoplankton Association Meeting, Firenze 18-20 September 1989 - Abstracts.","authors":"S. Monechi","doi":"10.58998/nina2314","DOIUrl":"https://doi.org/10.58998/nina2314","url":null,"abstract":"","PeriodicalId":186533,"journal":{"name":"Journal of Nannoplankton Research","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121771972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How many coccoliths are there in a coccosphere of the extant coccolithophorids? A compilation.","authors":"Tien-Nan Yang, K. Wei","doi":"10.58998/jnr2275","DOIUrl":"https://doi.org/10.58998/jnr2275","url":null,"abstract":"Introduction As an important component in the biogeochemical cycling of carbon and sulphur, and of global climate change (Westbroek et al., 1993), production of coccolithophorids and their fluxes in the ocean have drawn much attention in recent years (e.g. Kleijne, 1991; Honjo, 1996; Andruleit, 1997; Ziveri & Broerse, 1997; Broerse et al., 2000a, b, c; Jordan & Winter, 2000; Sprengel et al., 2000; Ziveri & Thunell, 2000; Cortes et al., 2001; Haidar & Thierstein, 2001; Yang et al., 2001 ). To be able to quantitatively estimate the flux of coccolithophorids in the ocean system, it is often desirable to convert counts of coccoliths into coccospheres, or vice versa. For example, Kleijne (1991) and Knappertsbusch (1993) documented the distribution of standing crops of coccospheres of holococcolithophorids in the Indian Ocean, Red Sea, Mediterranean Sea and North Atlantic Ocean, and of coccolithophorids in the Mediterranean Sea, respectively, by converting the counted coccoliths to coccospheres using existing data of coccolith/coccosphere ratios. More recently, Broerse et al. (2000a, b, c) and Ziveri & Thunell (2000) compiled coccolith and coccolithophorid data, and converted the data eventually into carbonate mass flux, based upon the coccolith mass estimates ofYoung & Ziveri (2000). The conversions in these previous studies, however, were applied to limited numbers of species, based upon available data from published literature. To facilitate a more complete quantitative study of coccolithophorid standing crops, and their contribution to carbonate flux, not only ratios of coccoliths/coccosphere of all species needed to be documented, but also some basic questions needed to be addressed, for instance, is the ratio shown by each taxon constant? If not, does the ratio vary with different oceanographic settings, or is it solely a function of ontogenetic development? Furthermore, for some dimorphic and dithecate coccospheres, the number of different kinds of coccoliths should be converted separately depending upon whether the coccosphere is complete or not. Various functions of coccoliths have been hypothesised, including protection, biochemical convenience, flotation and light-regulation (see Young, 1994 for review, and references therein). Intraspecific variation is a notable phenomenon in cultured Emiliania huxleyi (Linschooten et al., 1991). They found that new daughter-cells were covered with an average of 8-10 coccoliths, but the number increased to 15-20 before the next cell-division. The number of coccoliths also varies with nutrient availability. Linschooten et al. (1991)","PeriodicalId":186533,"journal":{"name":"Journal of Nannoplankton Research","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127965553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oligocene-Pliocene taxonomy and stratigraphy of the genus Sphenolithus in the circum North Atlantic Basin: Gulf of Mexico and ODP Leg 154.","authors":"J. Bergen, E. de Kaenel, S. A. Blair, T. Boesiger, E. Browning","doi":"10.58998/jnr2016","DOIUrl":"https://doi.org/10.58998/jnr2016","url":null,"abstract":"Sphenolithus is secondary only to the genusDiscoaster in Cenozoic nannofossil biostratigraphy, notably of primary importance for the Oligocene to Early Miocene. The research presented herein provides a framework for Oligocene to Middle Pliocene Sphenolithus, where gradations between individual taxa and their stratigraphic ranges are presented. Integration of schemes from BP, Amoco and Arco Vastar, to form a single composite Neogene calcareous nannofossil framework for the Gulf of Mexico basin, began around the turn of the century with focus on refining taxonomic concepts to solve stratigraphic discrepancies between the heritage schemes. Further study and bioevent calibration was accomplished through analyses of deep-water wells in the Gulf of Mexico along with research grounding the integrated framework to the “astronomical clock” of ODP Leg 154 back into the middle Early Oligocene at an average sample resolution of 21 kyr. Forty-two species are considered herein, in addition to the morphologically-similar Ilselithina fusa. Thirteen new species are introduced. Sphenolithus peartiae and Sphenolithus distentus are emended. Clarification of taxonomic concepts by the use of morphologic groups is supplemented with identification tables, drawings, and light photomicrographs. Iterative processes, in terms of size, are stressed.","PeriodicalId":186533,"journal":{"name":"Journal of Nannoplankton Research","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128280178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nannofossils and Upper Cretaceous (sub-)stage boundaries - state of the art.","authors":"J. Burnett","doi":"10.58998/jnr2041","DOIUrl":"https://doi.org/10.58998/jnr2041","url":null,"abstract":"","PeriodicalId":186533,"journal":{"name":"Journal of Nannoplankton Research","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130984187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calcareous nannoplankton as a tracer of the marine influence on the NW coast of Portugal over the last 14 000 years.","authors":"C. Guerreiro, M. Cachão, T. Drago","doi":"10.58998/jnr2107","DOIUrl":"https://doi.org/10.58998/jnr2107","url":null,"abstract":"A calcareous nannoplankton taphonomic and palaeoecological study was performed on cores from the Minho and Douro Estuaries (NW Portugal) and from the NW Portuguese middle continental shelf. Because certain nannoplankton species are taphonomically resistant to the highly energetic and aggressive conditions between the estuaries and the shelf, their sedimentary record acts as an oceanic tracer in such coastal domains. For the Late Quaternary, this allows interpretation of eustatic variation from the induced sequence of palaeoenvironmental changes. Palaeogeographically, the time-series pattern of nannofossil abundances in these coastal sediments is interpreted as follows: (1) persistently high amounts of nannofossils (2x107 nannofossils/g) are related to marine environmental conditions, produced by post-glacial flooding of pre-existing valleys; (2) the gradual increase in intermittency of nannofossil abundances through time indicates a regressive trend, first due to recovery of the estuarine conditions, followed by a total absence of nannofossils, indicating evolution towards complete emersion either by fluvial (Core CPF1) or barrier-beach sediments (Cores M1, M2, D1A and D1B). During the Late Holocene, the nannoplankton assemblages were similar to those found in Present Day neritic conditions. The main taxa comprise Gephyrocapsa spp., Helicosphaera carteri, Emiliania huxleyi and Coccolithus pelagicus sensu lato. An unexpected and extremely high percentage of H. carteri in the Douro Estuary’s mouth was likely related to local confinement, which probably provided adequate and particular nutrient concentrations that prompted opportunistic behaviour in","PeriodicalId":186533,"journal":{"name":"Journal of Nannoplankton Research","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129740760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"External and internal views of coccospheres: Notes on a new cracking technique.","authors":"T. Hildebrand-Habel, H. Mai","doi":"10.58998/jnr2121","DOIUrl":"https://doi.org/10.58998/jnr2121","url":null,"abstract":"","PeriodicalId":186533,"journal":{"name":"Journal of Nannoplankton Research","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130452649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new Eocene Chiasmolithus species: hypothetical reconstruction of its phyletic lineage.","authors":"D. Persico, G. Villa","doi":"10.58998/jnr2198","DOIUrl":"https://doi.org/10.58998/jnr2198","url":null,"abstract":"Chiasmolithus is abundant in Southern Ocean Ocean Drilling Program Sites 689, 738 and 748, and consequently provides an opportunity to study, in detail, evolutionary lineages and investigate the biostratigraphic distribution of some of the species. In particular, in the Middle to Late Eocene, a new species, Chiasmolithus eoaltus, has been recognised and distinguished from Chiasmolithus altus. Quantitative analysis highlights a gap between the last occurrence of C. eoaltus in the Upper Eocene and the first occurrence of C. altus in the Lower Oligocene. The morphological similarity is probably the result of convergent evolution. Additionally, the evolutionary steps that mark the phylogenesis of Chiasmolithus species during the Middle Eocene to Late Oligocene were investigated. Biostratigraphic and morphometric data permit reconstruction of a hypothetical phylogenetic tree, delineated by speciation events: we hypothesise that Chiasmolithus solitus gave rise to C. oamaruensis and C. eoaltus between 40.69 and 38.34Ma (Reticulofenestra reticulata Nannofossil Zone), followed by the evolution of C. altus from C. oamaruensis between 33.97 and 32.49Ma (Blackites spinosus Nannofossil Zone). A correlation between palaeoclimatic interpretations and the Chiasmolithus evolutionary tree underline that sea-surface temperature changes played a key role in the nannofossil evolutionary process, and suggest that phyletic gradualism, a recognised theoretical approach to evolutionary process, resulted from intraspecific variability subordinated to natural selection. This study represents, beyond the description of a new nannofossil species, confirmation of the neo-Darwinian concept of phyletic gradualism.","PeriodicalId":186533,"journal":{"name":"Journal of Nannoplankton Research","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124926892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}