Calcareous dinoflagellates in Cretaceous to Recent sediments of DSDP Hole 39-356

Calcareous dinoflagellates often dominate the dinoflagellate cyst assemblage in Cretaceous to Recent oceanic sediments. However, their distribution in Paleogene sediments has scarcely been studied. The investigation of samples from DSDP Site 356 for their calcareous dinoflagellate content revealed 35 mainly long-ranging taxa. The associations and characteristic wall types (pithonelloid, oblique, radial, tangential) fluctuate quantitatively and qualitatively in distinct stratigraphic patterns. Significant shifts, primarily at the K/T boundary and the Paleocene/Eocene boundary, reflect changes in environmental conditions. Certain dinoflagellates forming calcareous cysts, such as Operculodinella operculata, were well adapted to the relatively rapid change of environmental conditions at the K/T boundary, thus blooming to dominate the carbonate flux to the ocean floor. In contrast to the stable Paleocene associations, Eocene calcareous dinoflagellates show fluctuations in relative abundances. These fluctuations can possibly be attributed to redeposition related to increased seaward transport of specimens, due to strengthened western boundary currents. The flora includes two new genera, one new species, and two new forms: Retesphaera diadema Hildebrand-Habel, Willems et Versteegh, gen. et. sp. nov., Cervisiella saxea (Stradner, 1961) Hildebrand-Habel, Willems et Versteegh, gen. et comb. nov., Sphaerodinella? tuberosa forma elongata Hildebrand-Habel, Willems et Versteegh, comb. et forma nov., Sphaerodinella? tuberosa forma variospinosa Hildebrand-Habel, Willems et Versteegh, comb. et forma nov. Three new combinations are proposed: Cervisiella saxea (Stradner, 1961) Hildebrand-Habel, Willems et Versteegh, gen. et comb. nov., Operculodinella operculata (Bramlette et Martini, 1964) Hildebrand-Habel, Willems et Versteegh, comb. nov., and Sphaerodinella? tuberosa (Kamptner, 1963) Hildebrand-Habel, Willems et Versteegh, comb. nov. The genus Operculodinella Kienel, 1994 is emended.

Diatoms in Paleocene sediments of the southwestern South Atlantic

The taxonomy and stratigraphy of pelagic Paleocene diatoms from ODP Sites 698, 700, and 702 and DSDP Site 524 in the South Atlantic and DSDP Site 214 in the Indian Ocean are presented, as well as paleogeographic and paleoecologic implications. Eleven new species and one new variety are described and one new combination is proposed: Coscinodiscus cruxii sp. nov. Grunowiella palaeocaenica var. alternans var. nov. Hemiaulusl beatus sp. nov. Hemiaulusl ciesielskii sp. nov. Hemiaulusl conicus sp. nov. Hemiaulus kristoffersenii sp. nov. Hemiaulus nocchiae sp. nov. Hemiaulusl oonkii sp. nov. Hemiaulusl velatus sp. nov. Triceratium gombosii sp. nov. Trochosira gracillima comb. nov. Trochosira marginata sp. nov. Trochosira radiata sp. nov. Hole 700B provides one of the most continuous diatomaceous Paleocene profiles known. Stratigraphic ranges of diatom species from this and other Southern Hemisphere sites are calibrated against calcareous microfossil zones. The first-appearance datums of Triceratium gombosii, Hemiaulus incurvus, and Triceratium mirabile in Paleocene deep-sea sediments are useful for regional stratigraphic correlations. Quantitative analysis of the biosiliceous microfossil groups (diatoms, silicoflagellates, radiolarians, and archaeomonadaceae) shows that preservation of diatoms is confined primarily to the upper Paleocene (planktonic foraminifer Zones P3 and P4 and calcareous nannofossil Zones upper NP5 to lower NP9). In the lower Paleocene only short intervals in Hole 700B are diatomaceous. A correlation between the degree of silica diagenesis and the calcium carbonate content of the sediment is not obvious. Diatom species analysis reflects changes in the paleoenvironment between island-related upwelling conditions with highly diverse and well-preserved diatom assemblages and less productive periods resulting in less wellpreserved diatom assemblages with a higher content of robust neritic diatoms.

Diatom abundances in ODP Leg 114 holes

The practically continuous, paleomagnetically dated late Gauss-Brunhes sediment profiles of ODP Sites 699 and 701, south of the present Polar Front Zone (PFZ), and Site 704, north of the present PFZ, are used for a high-resolution study of abundance fluctuations of eight stratigraphic marker species in space and time. Ecological restrictions and preferences of the diatom species Hemidiscus karstenii, Actinocyclus ingens f. planus, Thalassiosira elliptipora, Thalassiosira kolbei, Thalassiosira vulnifica, Simonseniella barboi, Cosmiodiscus insignis, and Nitzschia weaveri are deduced. The ages of their first abundant appearance datums (FAAD), last-appearance datums (LAD), and last abundant appearance datums (LAAD) at the three sites are determined. The interpolated datum ages agree relatively well with those determined by other authors, if one interprets most of their LADs as LAADs. FAADs and LAADs produce more accurate datums than LADs. For the late Matuyama (younger than approximately 2.0 Ma), when PFZ fluctuations effected all three site sites, the datum ages determined agree within the methodically caused limits of accuracy for each datum. For the early Matuyama (older than approximately 2.0 Ma) the results can be interpreted as either that the ages of the FAAD of T. kolbei and LAAD of T. vulnifica datums determined at Sites 699 and 701 are more reliable or that these datums are diachronous between these two sites and Site 704. Such a diachroneity could be caused by different paleoceanographic conditions (stable subantarctic conditions over Site 704 and stable antarctic conditions over Sites 699 and 701). A few taxonomic changes were necessary. One new genus is defined (Simonseniella gen. nov.) and five new combinations are proposed: Simonseniella barboi (Brun) comb, nov., Simonseniella praebarboi (Schrader) comb, nov., Simonseniella curvirostris (Jousé) comb, nov., Thalassiosira elliptipora (Donahue) comb, nov., and Thalassiosira vulnifica (Gombos) comb. nov.

20 movies of x-ray tomograms of different Alpinia fossils

The fossil floras described by Dieter MAI and Harald WALTHER are invaluable for understanding the past plant diversity in Europe, and provide important information on the occurrence of taxa in the fossil record that is critical for evolutionary studies. Among the taxa they recognized were seeds assigned to the extant genus Alpinia ROXB. (Zingiberaceae, Zingiberales). We reinvestigated 28 specimens that were assigned to Alpinia arnensis (CHANDLER) MAI, Alpinia cf. arnensis, and Alpinia bivascularis MAI from the Ypresian (lower Eocene) of the UK, upper Eocene of Germany, and lower Miocene of Germany using non-destructive synchrotron-based X-ray tomography to reveal internal anatomy. None of the samples studied show an anatomy consistent with extant Alpinia or even Zingiberales. The fossils lack the globose shape, often striate external surface, seed coat structure, operculum, and micropylar collar seen in all Alpinia, and lack the chalazal chamber seen in many Alpinia species. Two specimens from the lower Miocene of Germany showed the structure of fruits of Caricoidea CHANDLER (Cyperaceae) with a single-layered exocarp, thick mesocarp, and sclerified endocarp. The other specimens are recognized as Carpolithes albolutum nom. nov. (incertae sedis) from the Ypresian of the UK, C. phoenixnordensis sp. nov. (incertae sedis) from the upper Eocene of Germany, C. bivascularis comb. nov. (incertae sedis) from the lower Miocene of Germany as well as indeterminate tegmens from the lower Miocene of Germany. This reinvestigation demonstrates that there is, as yet, no confirmed fossil record for the extant genus Alpinia. Furthermore, at least four different taxa are recognized from what had been two extinct species, enhancing our understanding of these important European Cenozoic carpofloras.

Eocene-Oligocene diatoms in the western Indian Ocean

The occurrence of diatom species in the Eocene-Oligocene sections of Ocean Drilling Program (ODP) Leg 115 sites and Deep Sea Drilling Project (DSDP) Sites 219 and 236 in the low-latitude Indian Ocean are investigated. Diatoms are generally rare and poorly preserved in the Paleogene sequences we studied. The best-preserved assemblages are found close to ash layers in early Oligocene sediments. The low-latitude diatom zonation established for the Atlantic region by Fenner in 1984 is fully applicable to the Paleogene sequences of the western Indian Ocean. Correlation of the diatom zones to the calcareous nannofossil stratigraphy of the sites places the Coscinodiscus excavatus Zone of Fenner within calcareous nannofossil Subzone CP16b. For the Mascarene Plateau and the Chagos Ridge, the times when the sites studied, together with the areas upslope from them, subsided to below the euphotic zone are deduced from changes in the relative abundance between the group of benthic, shallow-water species and Grammatophora spp. vs. the group of fully planktonic diatom species. The Eocene section of Site 707, on the Mascarene Plateau, is characterized by the occurrence of benthic diatoms (approximately 10% of the diatom assemblage). These allochthonous diatoms must have originated from shallow-water environments around volcanic islands that existed upslope from ODP Site 707 in Eocene times. In Oligocene and younger sediments of Sites 707 and 706, occurrences of benthic diatoms are rare and sporadic and interpreted as reworked from older sediments. This indicates that the area upslope from these two Mascarene Plateau sites had subsided below the euphotic zone by the early Oligocene. Only Grammatophora spp., for which a neritic but not benthic habitat is assumed, continues to be abundant throughout the Oligocene sequences. The area of the Madingley Rise sites (Sites 709-710) and nearby shallower areas subsided below the euphotic zone already in middle Eocene times, as benthic diatoms are almost absent from these Eocene sections. Only sites located on abyssal plains, and which intermittently received turbidite sediments (e.g., Sites 708 and 711), contain occasionally single, benthic diatoms of Oligocene age. The occurrence of the freshwater diatom Aulacosira granulata in a few samples of late early Oligocene and late Oligocene age at Sites 707, 709, and 714 is interpreted as windblown. Their presence indicates at least seasonally arid conditions for these periods in the source areas of eastern Africa and India. Three new species and two new combinations are defined: Chaetoceros asymmetricus Fenner sp. nov.; Hemiaulus gracilis Fenner, sp. nov.; Kozloviella meniscosa Fenner, sp. nov.; Cestodiscus demergitus (Fenner) Fenner comb, nov.; and Rocella princeps (Jouse) Fenner comb. nov.

Dinoflagellate cysts in surface sediments

Surface sediments at 439 sites throughout the North Atlantic Ocean and adjacent seas have been analyzed for dinoflagellate cysts in order to establish a reference database from which paleoenvironmental transfer functions can be developed. Laboratory procedures and systematics were standardized in order to avoid bias introduced by the selective loss of taxa and to facilitate site to site comparison. 371 sites were retained to develop the database that includes 41 taxa, some of which were grouped using morphological and/or ecological criteria. 27 taxa were retained for statistical purposes. Distribution maps of these latter taxa have been plotted on the basis of their relative abundance. Principal component analyses were performed in order to describe the distribution of assemblages. The relation between the assemblages, as well as the relative abundance of individual taxa, and selected sea-surface parameters are illustrated. The parameters which were considered include temperature and salinity for winter (February) and summer (August) together with the duration of sea-ice cover. Transfer functions using the best analogue method have been tested with a view to reconstruct past sea-surface parameters. Validation procedures on this transfer function demonstrate that more than 95% of the reconstructions are included within the interannual variability of modern sea-surface conditions. Therefore, these transfer functions give accurate results and can be applied to reconstructing paleo-temperatures and -salinities from analogous assemblages in Quaternary sedimentary sequences. Protoperidinium stellatum (Wall in Wall & Dale, 1968) Head, comb. nov. (basionym = Peridinium stellatum) is proposed as new, and Algidasphaeridium? minutum var. cezare de Vernal et al., 1989 ex de Vernal et al. is newly validated.

Distribution of desmoscolecida (Nematoda) in surface sediments of the Iberian Deep-Sea, North Atlantic (Table 1)

1. Desmoscolecida from the continental slope and the deep-sea bottom (59-4354 m) off the Portuguese and Moroccan coasts are described. 18 species were identified: Desmoscolex bathyalis sp. nov., D. chaetalatus sp. nov., D. eftus sp. nov., D. galeatus sp. nov., D. lapilliferus sp. nov., D. longisetosus Timm, 1970, D. lorenzeni sp. nov., D. perspicuus sp. nov., D. pustulatus sp. nov., Quadricoma angulocephala sp. nov., Q. brevichaeta sp. nov., Q. iberica sp. nov., Q. loricatoides sp. nov., Tricoma atlantica sp. nov., T. bathycola sp. nov., T. beata sp. nov., T. incomposita sp. nov., T. meteora sp. nov., T. mauretania sp. nov. 2. The following new terms are proposed: "Desmos" (ring-shaped concretions consisting of secretion and concretion particles), "desmoscolecoid" and "tricomoid" arrangement of the somatic setae, "regelmaessige" (regular), "unregelmaessige" (irregular), "vollstaendige" (complete) and "unvollstaendige" (incomplete) arrangement of somatic seta (variations in the desmoscolecoid arrangement of the somatic setae). The length of the somatic setae is given in the setal pattern. 3. Desmoscolecida identical as to genus and species exhibit no morphological differences even if forthcoming from different bathymetrical zones (deep sea, sublitoral, litoral) or different environments (marin, freshwater, coastal subsoil water, terrestrial environment). 4. Lorenzen's (1969) contention that thearrangement of the somatic setae is more significant for the natural relationships between the different genera of Desmoscolecida than other characteristics is further confirmed. Species with tricomoid arrangement of somatic setae are regarded as primitive, species with desmoscolecoid arrangement of somatic setae are regarded as more advanced. 5. Three new genus are established: Desmogerlachia gen. nov., Desmolorenzenia gen. nov. and Desmofimmia gen. nov. - Protricoma Timm, 1970 is synonymized with Paratricoma Gerlach, 1964 and Protodesmoscolex Timm, 1970 is synonymized with Desmoscolex Claparede,1863. 6. Checklists of all species of the order Desmoscolecida and keys to species of the subfamilies Tricominae and Desmoscolecinae are provided. 7. The following nomenclatorial changes are suggested: Desmogerlachia papillifer (Gerlach, 1956) comb. nov., D .pratensis (Lorenz, 1969) comb. nov., Desmotimmia mirabilis (Timm, 1970) comb. nov., Paratricoma squamosa (Timm, 1970) comb. nov., Desmolorenzenia crassicauda (Timm, 1970) comb. nov., D. desmoscolecoides (Timm, 1970) comb. nov., D. eurycricus (Filipjev, 1922) comb. nov., D. frontalis (Gerlach, 1952) comb. nov., D. hupferi (Steiner, 1916) comb. nov., D. longicauda (Timm, 1970) comb. nov., D. parva (Timm, 1970) comb. nov., D. platycricus (Steiner, 1916) comb. nov., D. viffata (Lorenzen, 1969) comb. nov., Desmoscolex anfarcficos (Timm, 1970) comb. nov.

Benthic freshwater diatom abundance in streams and seepage areas of northern James Ross Island between 2004-2009

Background and aim - The non-marine diatom communities in the Antarctic Region are characterized by a typical species composition, in close relationship with their environment. Despite the growing interest, the diatom flora of James Ross Island is only poorly known. The present paper discusses the diversity of limnoterrestrial diatoms on this island: seepages and streams. Methods - The diatom flora of 53 samples taken on the eastern side of the Ulu peninsula on James Ross Island has been studied using light and scanning electron microscopy. Key results - A total of 69 diatom taxa belonging to 26 genera have been observed. The genera Luticola, Diadesmis, Muelleria and Pinnularia dominated the species composition. The flora shows an interesting mixture of cosmopolitan and Antarctic species containing several species reaching on James Ross Island their most northern distribution in the Antarctic Region. The taxonomical position of one widespread Antarctic species, Psammothidium papilio (D.E.Kellogg, Stuiver, T.B.Kellogg & Denton) Kopalova & Van de Vijver comb. nov., is corrected. Conclusions - The limnoterrestrial diatom flora of James Ross Island has a rather low number of species, of which a large proportion shows a restricted Antarctic distribution.

Occurrence of Selenopemphix undulata sp. nov in late Quaternary sediments of the Pacific Ocean

Detailed palynological studies in the northeast (NE) Pacific, Strait of Georgia (BC, Canada), southeast (SE) Pacific and northwest Pacific (Dongdo Bay, South Korea) resulted in the recognition of the new dinoflagellate cyst species Selenopemphix undulata sp. nov. This species is restricted to cool temperate to sub-polar climate zones, where it is found in highest relative abundances in highly productive non- to reduced upwelling regions with an annual mean sea-surface temperature (aSST) below 16 °C and an annual mean sea-surface salinity (aSSS) between 20 and 35 psu. Those observations are in agreement with the late Quaternary fossil records from Santa Barbara Basin (ODP 893; 34°N) and offshore Chile (ODP 1233; 41°S), where this species thrived during the last glacial. This period was characterised by high nutrient availability and the absence of species favouring upwelling conditions. The indirect dependence of S. undulata sp. nov. abundances on nutrient availability during reduced or non-upwelling periods is expressed by the synchronous fluctuations with diatom abundances, since the distribution and growth rates of the latter are directly related with the availability of macronutrients in the surface waters.

Surface characteristics and metazoa occurrence at ice station PS67/006-1 during POLARSTERN cruise ANT-XXII/2 (Nov 2004-Jan 2005)

The surface and sub-ice layer habitats and their metazoan fauna were studied on a drifting pack-ice floe in the western Weddell Sea from 29 November 2004 to 1 January 2005 during the "Ice Station POLarstern" (ISPOL). Flooding of the floe occurred at some places, and the establishment of surface layers with a brownish colour due to growing algae was observed at several sampling sites. The average surface-layer temperature, brine salinity and brine volume were -1.4 °C, 25.3 and 54%, respectively. The temperature-salinity relationship in the surface layer was seldom at equilibrium conditions. Chlorophyll a (Chl a) concentrations in the brine varied between 1.0 and 53.5 µg /L. Surface-layer thickness, salinity, Chl a concentration and copepod abundances were generally higher at the edge of the floe than in the inner part. The sympagic copepod species Drescheriella glacialis/racovitzai and Stephos longipes, with abundances ranging between 0 and 3830 ind/L (median: 2 ind/L) and 0 and 1293 ind/L (median: 4 ind/L), respectively, were the dominant members of the surface-layer meiofauna. Their populations consisted mainly of adults and early naupliar stages, which points to an active reproduction of these species within the surface layer. Other taxa found in the surface layer were undetermined turbellarians, the gastropod Tergipes antarcticus, and, for the first time, the ctenophore Callianira antarctica, and the amphipods Eusirus antarcticus and Eusirus tridentatus. During the course of our study, slight melting at the ice underside took place, releasing sympagic organisms to the water column. Chl a concentrations in the sub-ice water layer were very low (0.1-0.5 µg /L), except for 25 December when the Chl a concentration at 0 m depth increased to 2.3 µg /L. The most dominant sympagic copepod species found in the sub-ice layer was Ectinosoma sp., with abundances ranging between 1 and 599 ind/m**3 (median: 25 ind/m**3). Other sympagic copepod species occurring regularly in this habitat were D. glacialis/racovitzai, Diarthrodes cf. lilacinus, Idomene antarctica and S. longipes. All of these sympagic species were generally found in higher abundances at 0 m depth underneath the ice than at 5 m depth, in contrast to pelagic copepod species that occurred more frequently at 5 m depth. Niche separation and probable life-cycle strategies of dominant sympagic metazoans are discussed.