Tortonian ostracodes of Southwestern Europe

This paper analyzes the lithostratigraphic features and the ostracode associations of the Tortonian deposits located in the western and central sectors of the Guadalquivir basin (S Spain). Eight facies associations are defined (FA-1 to FA-8), being deposited in fluvial to upper bathyal paleoenvironments. The ostracofaune confirms the Tortonian age of these deposits, where three ostracode associations are defined: (a) infralittoral (i.e. Urocythereis favosa, Cytheretta orthezensis, Callistocythere spp.); (b) circalittoral (i.e. Costa batei, Celtia quadridentata, Echinocythereis scabra, Pterygocythereis ceratoptera/jonesii); and (c) outer platform/talus (Henryhowella asperima; Cytherella spp.; Krithe spp.). A comparison with the Tortonian associations of southwestern France and Portugal permits to define a common ostracod zonation for southwestern Europe for this period.     

Productivity and Distribution of Trichoptera Larvae in a Colorado Mountain Stream

Summary From June 1968 to late May, 1969 collections of more than 20,600 immature Trichoptera were made from the St. Vrain River of Colorado. Agapetus sp., Arctopsyche grandis, Brachycentrus americanus, Ecclisomyia maculosa, Hydropsyche sp., Hydropsyche occidentalis, Helicopsyche borealis, Leptocella sp., Neothremma alicia, Rhyacophila acropedes, and Sortosa sp. were taken at eight sites ranging from 1565 to 3200 m in altitude. The Trichoptera of the St. Vrain exhibited a distinct altitudinal zonation with Zone I (1565 m) dominated by Leptocella, Hydropsyche sp., and Helicopsyche borealis; Zone II (1750 to 2350 m) was dominated by Brachycentrus americanus and Hydropsyche occidentalis; Zone III (2350 m) was considered a transitional area. In Zone IV (2650 m) and Zone V (2950 to 3250 m ) Neothremma alicia and Arctopsyche grandis were the most successful genera, respectively. Temperature is proposed as the major variable controlling attitudinal zonation.Standing crop productivity of Trichoptera was determined from timed collections and expressed as population density (number of organisms collected per 30 minutes) and organic biomass (dry organic matter represented by organisms collected per 30 minutes). Intermediate altitudes (2300 m) exhibited the lowest productivity but greatest species diversity. Highest productivity occurred below 1600 m but organic biomass was surprisingly high above 2900 m. Changes in productivity in relation to altitude are discussed in relation to temperature, food availability, severe flooding, and other variables. Productivity on a yearly basis was found to be greatest in spring and at minimum levels during autumn and early winter. The holometabolous life cycle of Trichoptera, temperature, and current seem to be the major governing factors of seasonal productivity.     

Miocene ostracodes of cold seep settings from northern Apennines (Italy)

The Miocene Termina Formation of the northern Apennines (Italy) contains thin marly limestone or marly sandstone bodies rich in macrofauna mainly consisting of large lucinid clams. Modern representatives of this fauna occur in cold seep settings where they house chemosymbiotic bacteria. Moreover, these rocks record a δ¹³C-depletion confirming their origin influenced by a cold seep. The Miocene sections of Sasso delle Streghe and Sarsetta (near Modena) represent classic examples of cold seeps. These sections consist of marls and marly sandstones, respectively, with lucinids (Sasso delle Streghe) or bioclastic sands with lucinids (Sarsetta); both sections are capped by the Sandstones of Montebaranzone. They yield ostracodes that are mainly represented by deep-water filter-feeder species (Platycopa, i.e. Cytherella sp.) and numerous deposit-feeders (Podocopa: i.e. Neonesidea and Krithe), together with species frequently occurring in shallow water environments. These assemblages are able to colonize disaerobic environments such as cold seeps. Although some authors consider the filter-feeders as dominant taxa in disaerobic settings, our data do not provide evidence of significant differences in the ostracode assemblage composition between the deposits originated in seafloors with or without seepage influence. However, the number of specimens is greater in seafloors devoid of seepage influence.     

New lower Callovian ostracodes from the Kursk Region

Lower Callovian deposits (subpatruus and koenigi ammonite zones) in the Mikhailovskii Mine section (Central Russia, Kursk Region) yielded 13 ostracode species (two of them are new) belonging to ten genera. This ostracode assemblage corresponds to ostracode beds with Praeschuleridea wartae-Pleurocythere kurskensis. The stratigraphic range of these beds corresponds to three ammonite biohorizons: Chamoussetia crobyloides, Kepplerites gowerianus gowerianus, and K. indigestus. Three distinct ostracode assemblages have been defined in the section based on their taxonomy and occurrence pattern. Two new species, Pleurocythere kurskensis sp. nov. and Pseudohutsonia wienholzae sp. nov., are described.     

Erster Nachweis der Agoniatitidae (Ceph.) im Unterdevon von Nevada (USA)

From the Lower Devonian of Nevada (USA) a newly discovered ammonoid,Mimagonia- titesi n. sp., aff.M. angulostriatus Bogoslovski 1969, is described. The specimen was found in strata belonging to the highserotinus Zone of the conodont chronology resp. the lowerholynensis Zone according to the tentaculite zonation (late Dalejan resp. Upper Emsian). Suture line and umbilicus are not preserved; therefore the systematic position is not fully verified. But the fragmentary shell provides strong indications toMimagoniatites Eichenberg, a genus up till now unknown from the central Cordilleran Province.     

Global radiolarian zonation for the Pliensbachian, Toarcian and Aalenian

Jurassic radiolarians from 220 samples in Queen Charlotte Islands, B.C., Williston Lake, B.C., east-central Oregon, Baja California Sur, southern Spain, Austria, Slovenia, Turkey, Oman, Japan and Argentina were studied in order to construct global zonation for the Pliensbachian, Toarcian and Aalenian stages. Well-preserved faunas from continuous stratigraphic sections in Queen Charlotte Islands provide the most detailed record for this time interval, and all collections are tied to North American ammonite zones or assemblages. Collections from nearly all other areas lack independent dating except for early Toarcian carbon-isotope dating in Slovenia and late Aalenian ammonites in Spain.A database of 197 widely distributed updated taxonomic species was used to construct a Unitary Association (UA) zonation for the interval. A global sequence of 41 UAs was obtained for the top of the Sinemurian to the base of the Bajocian. The first and the last UAs represent the Late Sinemurian and the Early Bajocian respectively. The remaining 39 UAs were merged into nine zones (four Early Pliensbachian, one Late Pliensbachian, one Early Toarcian, one Middle-Late Toarcian, and two Aalenian) according to prominent radiolarian faunal breaks and ammonite data. The new zones are the Canutus tipperi - Katroma clara Zone (latest Sinemurian/earliest Pliensbachian); Zartus mostleri - Pseudoristola megaglobosa, Hsuum mulleri - Trillus elkhornensis and Gigi fustis - Lantus sixi zones (Early Pliensbachian); Eucyrtidiellum nagaiae - Praeparvicingula tlellensis Zone (Late Pliensbachian); Napora relica - Eucyrtidiellum disparile Zone (Early Toarcian); Elodium pessagnoi - Hexasaturnalis hexagonus Zone (Middle and Late Toarcian); Higumastra transversa - Napora nipponica Zone (early Aalenian); and Mirifusus proavus - Transhsuum hisuikyoense Zone (late Aalenian). These zones can be correlated worldwide and link previously established UA zonations for the Hettangian-Sinemurian and the Middle to Upper Jurassic. The new zonation allows high-resolution dating in the studied interval and provides a solid basis for analyzing faunal turnovers and the paleobiogeography of Jurassic radiolarians.     

Revision of Famennian-Tournaisian (Late Devonian – Early Carboniferous) conodont biostratigraphy of Sardinia,Italy

Conodont biostratigraphy of the Famennian and Tournaisian of Sardinia is provided on the basis of all data available in the literature. More than 130 conodont taxa documented from this time-interval allow recognition of nineteen conodont biozones. The zonation scheme adopted here is broadly similar to the standard zonation schemes used in the Upper Devonian and Lower Carboniferous, though a few variations are needed to better accommodate the species occurrences in Sardinia: the velifer Zone and the styriacus Zone have been reintroduced, even though with slightly different meanings than previously used; the Lower praesulcata Zone is expanded to include the Middle praesulcata interval. The Upper praesulcata Zone and the sulcata Zone are missing. All zones are described and discussed and a complete list of bioevents is provided.     

Marine ostracodes from Paleogene hydrocarbon seep deposits in Washington State,USA and their ecological structure

Invertebrate fossils described from ancient hydrocarbon seep deposits represent diverse groups, e.g., brachiopods, mollusks, decapod crustaceans, worm tubes, and rare echinoderms, but the fossil record of ostracodes from hydrocarbon seep deposits is still very limited, making their ecology and evolutionary history still little known. We found fossil ostracodes in eight Eocene to Oligocene hydrocarbon seep deposits in the Humptulips, Lincoln Creek, Makah, and Pysht formations in western Washington State, USA. They represent eleven taxa belonging to genera found in a wide range of shelf to slope habitats: Acanthocythereis, Loxoconcha?, Cytherella, Cytheropteron, Macropyxis?, Krithe, Paracosta, Pontocythere?, Propontocypris, Palmoconcha, and Neonesidea? Acanthocythereis acroreticulata from one late Oligocene seep deposit in the Lincoln Creek Formation is the oldest and northernmost record for this species. The hydrocarbon seep ostracode faunas from Washington appear to be benthos-dominated, showing the same ecological structure and pattern of phylogenetic relatedness as ostracodes from Miocene and Quaternary seep sediments from Italy and off Ireland. We suggest that the benthos-dominated structure has been stable for ostracodes in hydrocarbon seep environments and/or has a higher preservation potential than the nektobenthos-dominated structure.     

Taxonomy, biostratigraphy and paleoecology of Cenomanian and Turonian ostracodes from the Western Interior Basin, Southwest Utah, USA

Cenomanian-Turonian ostracodes are reported from the western Colorado Plateau (Western Interior Basin) in the United States. Fifteen genera and twenty species are illustrated, six of which are new: Cytheromorphaperornata nov. sp., Looneyellaleckiei nov. sp., Asciocythereposterangulata nov. sp., Asciocytherearizonensis nov. sp., Cytheropteronclavifragilis nov. sp. and Hourcqiadakotaensis nov. sp. Three ostracode interval zones are proposed that broadly correspond to the existing late Cenomanian through to Middle Turonian Ammonite-zones of Kauffman et al. (1993). Paleoenvironments range from estuarine to coastal plain.     

New Ordovician ostracodes from Himalaya and their palaeobiological and palaeogeographical implications

Silicified representatives of the ostracode orders Binodicopa, Palaeocopa and Podocopa have been recovered from the late Ordovician Pin Formation, Spiti, NW Himalaya area. Benthic binodicopes are distinctly more abundant than the palaeocope and podocope ostracodes. The binodicopes show biogeographical relations to Australia at the generic level, which supports the close palaeogeographic position of these continents. By contrast, the palaeocope and podocope taxa show close relations to Baltica and Bohemia even at the species level, which may suggest a pelagic or epipelagic mode of life since these regions are separated from each other by the broad and deep waters of Palaeotethys. New taxa are Vendona crassiplicata nov. sp., Glossomorphites himalayaensis nov. sp., Pilla pinensis nov. sp. and Pinpilla u-formis nov. gen. nov. sp.     

New and little-known ostracode species from the Middle Neopleistocene to Holocene of the southeastern West Siberian Plain

New data are provided on the ostracode fauna of the Middle Neopleistocene to Holocene of the southeastern West Siberian Plain. Several species are recorded for the first time in the West Siberian Plain: Fabaeformiscandona aff. hyalina (Brady et Robertson), F. harmsworthi Scott, F. holzkampfi Hartwig, Pseudocandona insculpta Müller, Candona weltneri Hartwig, C. inaequivalvis Sars, and C. muelleri jacutica Pietrzeniuk. New evidence is presented on the distribution of the species Pseudocandona stagnalis Sars, Eucypris pigra (Fischer), Dolerocypris fasciata Fischer, Cyclocypris ovum Müller, and C. triangula Negadaev. New species, Candona kazminae sp. nov. and Ilyocypris pustulata sp. nov., are described. The study resulted in establishing the Late Karginian ostracode association.     

Danian/Selandian boundary stratigraphy,paleoenvironment and Ostracoda from Sidi Nasseur,Tunisia

Two detailed records (NSF and 05NSC, Sidi Nasseur, Tunisia) across the Danian/Selandian (D/S) boundary were investigated for their micropaleontological content. Calcareous nannofossils and planktic foraminifera provided a biostratigraphic framework. The interval spans part of planktic foraminiferal Zone P2, Subzone P3a and part of Subzone P3b. This corresponds to calcareous nannoplankton Zone NP4. Using a more detailed nannofossil zonation the studied section spans part of Zone NTp6, Zone NTp7a and part of NTp7b. Quantitative ostracod and qualitative benthic foraminiferal data were used to characterize environmental changes across the D/S boundary. The two subsections have yielded a total of 50 ostracod taxa. The ostracod assemblage of the entire section belongs to the Southern Tethyan Type showing subtle but distinct changes up section. Based on statistical analysis of the quantitative ostracod data, faunal changes at a glauconitic maker bed (P3a/P3b boundary) were demonstrated. The local Reticulina proteros assemblage, with the typical species R. proteros, Oertliella vesiculosa and Cytheroptheron lekefense, is gradually replaced by the Protobuntonia nakkadii assemblage, with the typical species Cristaeleberis arabii, Xestoleberis tunisiensis, Cytheropteron sp. and P. nakkadii, across the glauconitic bed. The benthic foraminifera also demonstrated distinct changes at this marker bed. The changes in ostracods and foraminifera are related to changes in paleoproductivity and an overall relative sea-level fall.The lithological and faunal changes at the P3a/P3b zone boundary within the Sidi Nasseur sections seem to correspond to the D/S boundary in the type region in Danmark and are characterized by a significant hiatus, yielding this section not suitable as a GSSP candidate for this boundary.     

New records of early Middle Jurassic belemnites in the French Subalpine Basin and their paleobiogeographic significance

A biostratigraphic and systematic study based on belemnites collected along with ammonites was performed on four sections in the Subalpine Basin (SE France): Lac du Castillon and La Baume (Castellane area), Galabrun and Grand Lara (Gap area). The specimens, originating from hemi-pelagic marl-limestone alternations in the lower part of the “Calcaires à Zoophycos” Formation, are dated from Middle Aalenian (Murchisonae Zone) to Lower Bajocian (Humphriesianum Zone). Five belemnite taxa (Megateuthis elliptica, Holcobelus munieri, H. trauthi, Pachybelemnopsis roettingensis, Hibolithes sp.) have been identified, and two more taxa are reported in an open nomenclature (Belemnitida incertae sedis sp. 1 and sp. 2). The biostratigraphic range of the belemnite fauna is established. The new findings contribute to a more detailed understanding of the paleobiogeography of holcobelid belemnites that flourished at the northern margin of the Tethys Ocean and formed a distinct sub-Mediterranean fauna. The association herein described is similar to the fauna of the Calabro-Peloritani Arc (Calabria, Italy), a further hint for the supposed paleogeographic position of the latter during the Middle Jurassic.     

New latest Coniacian to middle Campanian foraminiferal data from the lower Zongshan Formation in the Chaqiela section,Gamba, southern Tibet

A first and detailed foraminiferal biostratigraphic work on the lower part of the Zongshan Formation (Limestone I and Calcareous Marl I sequence) in the Chaqiela section, Gamba, southern Tibet, allows the recognition of three latest Coniacian to middle Campanian planktic foraminiferal biozones: Dicarinella asymetrica Total Range Zone, Globotruncanita elevata Partial-Range Zone, and Contusotruncana plummerae Interval Zone. The base and top of the Santonian Stage in the Chaqiela section were placed at the lowest occurrence (LO) of Globotruncana linneiana and the highest occurrence (HO) of Dicarinella asymetrica, respectively. The deposition of the latest Coniacian to middle Campanian sediments of the lower Zongshan Formation in the Chaqiela section seems to have been continuous or at least without any major gap based on the planktic foraminiferal biozones and events.     

Toarcian (Lower Jurassic) brachiopods in Asturias (Northern Spain): Stratigraphic distribution, critical events and palaeobiogeography

Brachiopod assemblages recorded in the Toarcian outcropping of the Asturian coast, between Gijón and Ribadesella, are described. In the Tenuicostatum Zone of the Early Toarcian, an assemblage dominated by Gibbirhynchia cantabrica nov. sp., which also includes some other species of North European affinities, has been recorded. Brachiopods disappear in the region at the end of this Zone, coinciding with a sedimentary episode of black shales, and they are not recorded again until the Variabilis Zone of the Middle Toarcian. Between this zone and the Aalensis Zone, several species appear with wide stratigraphic distribution but scarce representation, except for Soaresirhynchia renzi, which is very abundant, particularly in the Insigne Subzone. This assemblage differs from the ones recorded in other nearby Spanish basins and can be related to the ones described in part of the Lusitanian Basin (Portugal), Western Pyrenees and South-Western France. This similarity can be related to environmental characteristics, such as the existence in these cases of an external, relatively deep platform environment.     

湖北宜昌地区晚奥陶世三叶虫动物群及分带序列

从湖北宜昌黄花场和普溪河桥宝塔组剖面获得的新材料,极大地丰富了华南晚奥陶世三叶虫动物群内容,包括22属、1亚属、31种之多。新材料保存完美,很大程度上完整了有关三叶虫的形态特征。RemopleuridesamphitryonoidesLu,1975一种由于新发现了活动颊、唇瓣、胸部及尾部,证明它确实是Remopleurides的成员,排除了对该种归属的怀疑。文中建立了1新属和2新种:Pentacopygepuxiheensisgen.etsp.nov.,Lamproscutellum?limbatumsp.nov.。同时,以桨肋虫类为基础在宝塔组Nankinolithus带之下进一步划分出4个三叶虫带,从下到上依次为Pentacopygepuxiheensis间隔带,Hexacopygeyichangensis间隔带,Remopleuridesamphitryonoides延限带(普溪河段,卡拉道克中期),和Dislobosaspisguizhouensis延限带(临湘段下部,卡拉道克晚期)。     

Late Carboniferous palynostratigraphy of the Itararé Subgroup, northeastern Paraná Basin, Brazil

A new biozonation is proposed for the Late Carboniferous strata of the northeastern Paraná Basin (São Paulo and Paraná States), based on well-preserved palynological assemblages recovered from outcrops and core samples retrieved from the Itararé Subgroup. Assemblages include forty-nine species of trilete spores and twenty-five pollen species. The oldest biozone, the Ahrensisporites cristatus Interval Zone (AcZ), in the basal portion of the Itararé Subgroup, includes eleven exclusive spore species, and is assigned a Pennsylvanian (late Bashkirian to Kasimovian) age. The overlying proposed biozone, the Crucisaccites monoletus Interval Zone (CmZ), dated late Pennsylvanian (Kasimovian to Gzhelian), ranges approximately from the top of the lower portion to the middle portion of the Itararé Subgroup, bears only one exclusive species of pollen. Both zones are characterized by the dominance of trilete spores and monosaccate pollen grains, including also few taeniate pollen grains. Furthermore, the basal Protohaploxypinus goraiensis Subzone of the Vittatina costabilis Interval Zone (VcZ) is broadly recognized for the first time in the upper portion of the Itararé Subgroup in the northeastern Paraná Basin. This subzone is attributed to the Early Permian (Early Cisuralian), and is characterized by the dominance of monosaccate pollen grains, a significant increase of taeniate grains (mainly Protohaploxypinus spp.), apart from the appearance of polyplicate pollen (Vittatina spp.). Reference sections and the main characteristics of the two new zones (AcZ and CmZ) are presented, along with a preliminary palynological correlation and discussion on their ages.     

Freshwater fish otoliths from the Deccan Trap associated sedimentary (Cretaceous-Tertiary transition) beds of Rangapur,Hyderabad, District,Andhra Pradesh,India

The present paper describes 12 species of fish otoliths recovered by washing and screening processes from the Deccan Trap associated sedimentary (Intertrappean) beds exposed near Rangapur, Hyderabad District, Andhra Pradesh, India. The present collection of otoliths contains four major groups: Clupeomorpha (“Clupeidarum” sp.), Osteoglossomorpha (“Osteoglossidarum” deccanensis sp. nov., “O”. intertrappus sp. nov. and “Notopteridarum” nolfi sp. nov.), Protacanthopterygii (“Salmoniformorum” rectangulus sp. nov.), and Percomorpha (Dapalis sp., “Apigonidarum” ovatus sp. nov., “Serranidarum” sp., “Percoideorum” ellipticus sp. nov., “P.” rangapurensis sp. nov., “Percoideorum” sp. 1 and “Percoideorum” sp. 2). This collection of otoliths represents freshwater lacustrine deposition of the sediments. The age of the Intertrappean beds is considered Uppermost Cretaceous to Palaeoncene on the basis of freshwater ostracode (Paracypretta jonesi, Mongolianella hislopi and Candoniella sp.) and charophyte (Platychara perlata and Nemegtichara sp.) assemblages.     

Revised radiolarian zonation of the Upper Cretaceous Izumi inter-arc basin (SW Japan)

The radiolarian zonation of the Izumi Group is revised for an integrated biostratigraphy across the Campanian/Maastrichtian boundary, together with the ammonite occurrence, fission track and magnetostratigraphic calibration of the acidic tuff key beds. The significance of direct correlation in the same sections, between macro- and micro-fossils (i.e. between relatively near-shore nektonic and turbiditic planktonic-fauna) is discussed in relation to the litho- and bio-facies of the Izumi group. Late Cretaceous paleoceanographic changes inferred from the studied radiolarian fauna represent a regional marker event for the chronostratigraphic correlation of continental shelf to turbidite deep-sea sequences, which accumulated on a mid latitudinal margin facing towards the NW paleo-Pacific. The proposed Campanian/Maastrichtian boundary is at the limit between Pachydiscus awajiensis and Nostoceras hetonaiense ammonite zones. This boundary corresponds to the radiolarian last occurrence of Amphipyndax pseudoconulus (= A. enesseffi), Archaeodictyomitra sliteri, Dictyomitra formosa, D. koslovae and Rhopalosyringium magnificum at the top of the Myllocercion acineton Assemblage Zone (uppermost Campanian), and the first occurrence of Clathrocyclas gravis and Dorcadospyris sp. A, at the base of the Maastrichtian C. gravis Assemblage Zone. The new data settle partly a chronostratigraphic discrepancy between radiolarian and ammonite zonations in the Izumi Group, which was pointed out previously by Ishida et al. (2010).     

Hydraulic sorting of microbiota in calciturbidites— A dinantian case study from the rheinische schiefergebirge,Germany

Summary A calciturbidite bed from the lower part of the Kieselkalk Formation (late cd II) at Wallau, eastern Rheinisches Schiefergebirge, displays ideal grading of reworked calcareous shallow-water microbiota, ranging from plurimillimetric agglutinated foraminifers and fragments of calcareous algae (Koninckopora sp.) to plurimicronic calcispheres, radiolarians and sponge spicules. Microbiota derived from all levels of the platform. Correspondingly, several carbonate microfacies types could be discerned. The early diagenetic micrite base of the turbidite preserved the anoxic basinal facies. The turbidite bed belongs to Foraminiferal Zone 15 (V3bα), theAlbaillella cartalla Zone (radiolarian chronology), and is the Lower and part of the Uppertexanus Zone (standard conodont zonation). From the few published data on foraminifers, the Kieselkalk is thought to range from Mid Viséan V2b to Late Viséan V3b gamma.