Description: Publication date: 15 January 2015 Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 418 Author(s): Wenkun Qie , Jiangsi Liu , Jitao Chen , Xiangdong Wang , Horng-sheng Mii , Xionghua Zhang , Xing Huang , Le Yao , Thomas J. Algeo , Genming Luo An integrated study of the litho-, bio-, and chemostratigraphy of the Devonian–Carboniferous boundary at four sections (Qilinzhai, Malanbian, Gedongguan and Long'an) in South China was undertaken in order to better understand paleoenvironmental changes and controls on δ 13 C carb variation during the Hangenberg Crisis. Sedimentological data record a major regression in the Middle Siphonodella praesulcata Zone, which coincided with the Hangenberg Extinction (HE) in South China. Our new δ 13 C carb data document a negative δ 13 C carb shift near the base of the Middle S. praesulcata Zone, which may have been related to the HE. Prior to and during the HE, respiration of organic matter contributed abundant 12 C-enriched dissolved inorganic carbon (DIC) to the restricted Nanning carbonate platform, resulting in a negative vertical δ 13 C DIC gradient in the study area. In the Upper S. praesulcata Zone, all four sections exhibit a positive δ 13 C carb shift, suggesting that a vigorous biological pump existed in the aftermath of the latest Devonian glaciation. However, peak δ 13 C carb values differ markedly among the study sections, suggesting that local carbon cycling processes played an important role during the initial post-glacial transgression.

Description: Publication date: 15 January 2015 Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 418 Author(s): R. Graziano , A. Raspini The stratigraphic signature of the global Late Aptian cooling episode and sea level lowstand has been investigated in the Mt. Faito section of the Apennine Carbonate Platform (ApCP) of southern Italy. Several, meter scale fine-grained limestone intervals with abundant quartz pseudomorphs after anhydrite and minor calcite pseudomorphs after gypsum are present in the middle-upper Gargasian straddling the marly Orbitolina Level, a regional key-marker correlative with part of the Fallot Oceanic Anoxic Event. The evaporite-rich intervals were deposited in a mudflat-saltern setting and together with frequent transgressive shallow-marine interlayers alternate quite regularly with lacustrine, paralic or very shallow-marine deposits suggestive of overall wetter conditions. Three-to-five couplets of cyclic arid–wet phases are thus identified. Their timing and duration, determined by an original cyclostratigraphically constrained age model tuned with the astrochronology from deep-water Tethyan reference sections, suggest fluctuating hydroclimatic conditions (arid/semiarid vs. wet phases) over time scales as brief as 100 and 400 ky. They are considered to reflect astronomically-induced latitudinal migrations of intertropical climate belts. A secular climate shift from arid to humid conditions, supra-regionally correlatable across the Upper Gargasian of the Tethyan realm, is dated at ~ 118.1 My. It corresponds to the onset of persistent lacustrine deposits on the partially emerged ApCP and of abundant river-borne supply of siliciclastics along the opposing Tethyan margin. The observed climate fluctuations occurred during a major ApCP subaerial exposure which lasted for ~ 4.4 My. Precise supra-regional correlations suggest that the platform exposure was glacioeustatic in origin and coeval with a long-lived Late Aptian cooling episode which interrupted the mid-Cretaceous greenhouse. Biostratigraphic and astrochronological tuning from the ApCP indicates that the glacioeustatic lowstand terminated in the earliest Albian, just above the O. reicheli key-marker. Graphical abstract

Description: Publication date: 15 January 2015 Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 418 Author(s): M-L. S. Goudeau , G.-J. Reichart , J.C. Wit , L.J. de Nooijer , A.-L. Grauel , S.M. Bernasconi , G.J. de Lange Holocene rapid climate change (RCC) events, such as the Little Ice Age (LIA), are thought to have influenced average annual temperatures only marginally, but to have affected winter temperatures relatively strongly. With summer temperatures relatively unaffected, reconstructing climate change at a seasonal resolution is crucial to fully capture Holocene climate variability. Mediterranean climate is highly seasonal, being influenced by the subtropical high-pressure belt in summer and the mid-latitude westerlies combined with outbreaks of polar winds in winter. We identified events of high- and low-detrital input to the Gulf of Taranto (Central Mediterranean Sea), anticipated to be linked to humid and dry conditions, respectively and, thereby, potentially reflecting seasonal contrasts. These events represent the Bronze Age (BA), Roman Humid Period (RHP), Medieval Climate Anomaly (MCA), LIA and present-day, and were selected for the analysis of single specimen Globigerinoides ruber (white) carbonate chemistry (Mg/Ca, δ 18 O and δ 13 C). The dynamic range found for these parameters for the measured single individuals in the most recent interval reflects the present-day seasonal contrasts in temperature and precipitation, albeit with a bias towards the summer season. These results are compared with high-resolution (〈 15 years/sample) Sea Surface Temperature (SST) and Bottom Water Temperature (BWT) reconstructions based on the δ 18 O of G. ruber (white) and Mg/Ca of benthic foraminifer Hyalinea balthica . Although the seasonal temperature contrast remains relatively stable, significant winter cooling is observed during the BA and LIA. Connections between high-latitude climate (winter conditions) and low-latitude climate (summer conditions) appear not straightforward during RCC events. This results in changes in the moisture balance, and in shifts in seasonal dominance between RCCs. During the LIA, winter-like conditions (cold and humid) prevail throughout the year. In contrast, winters are dry and cold during the BA, and are accompanied by dry and warm summers, suggesting year-round aridity and a relatively high seasonal temperature contrast. This could have had a profound impact on early agriculture in Southern Italy.

Description: Publication date: 15 January 2015 Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 418 Author(s): Johannes Klietmann , Lars W. van den Hoek Ostende , Doris Nagel , Michael Rummel Many Miocene localities yielded considerable numbers of eulipotyphlan fossils. The group as a whole is generally considered to be indicative for humid environments, but little is known about the preferences of specific taxa. We discuss the insectivores found in the German fissure filling Petersbuch 28, including an insectivorous marsupial, in an attempt to refine the knowledge of the preferred environments of insectivores. For this, we compared the assemblage in quantitative analyses with other insectivore assemblages of similar age. Our results show that, in full accordance with previous hypotheses, dimylids, most moles and shrews were shown to be indicators for humid environments, like swamps or humid forests, whereas the hedgehogs, the moles Desmanodon and Theratiskos and the shrew Oligosorex were more common in dryer environments.

Description: Publication date: 15 January 2015 Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 418 Author(s): M. Lamentowicz , M. Gałka , Ł. Lamentowicz , M. Obremska , N. Kühl , A. Lücke , V.E.J. Jassey In this study, we present a record spanning the last 4000 years from a Baltic bog (Kusowskie Bagno) in northern Poland. Using numerous biotic and abiotic proxies, such as testate amoebae (depth to water table reconstructions), stable carbon isotopes ( 13 C), plant macrofossils (proxies for local vegetation and mire surface wetness), pollen and spores (proxies for regional vegetation and human impact), we reconstructed and identified the regional hydro-climatic signal of Kusowskie Bagno bog and compared it to other bog records around the Baltic Sea. Our aims were to: 1) combine the species traits of bryophytes and testate amoebae, and more common proxies (isotopes, plant micro-and macro-remains) to infer past peatland development, 2) compare the hydro-climatic signal of Kusowskie Bagno bog to existing records around the Baltic Sea. We found that Kusowskie Bagno bog was very wet during the last 4000 years, and even drainage and peat exploitation had not disturbed its hydrology in northern part in the last 200 years. Carbon isotopes and plant macrofossils were significantly related to specific traits of testate amoebae, which in turn reflected the water table changes over the last 4000 years. Kusowskie Bagno recorded at least the following wet shifts: AD 250, 550, 850, 1250 and 1700, while wet conditions occurred during the Migration period at ca AD 550. Furthermore, the testate amoeba-based quantitative wetness reconstruction in Kusowskie Bagno bog resembles the pattern observed in other sites around the Baltic, i.e., Estonia, Finland, Ireland, northern Britain and the 7500-year record from the Stążki bog, northern Poland. Our results provided statistically validated evidence that interactions between plant and microbe need to be more considered further to reconstruct past hydrological. This is the first study of past hydro-climatic changes in peatlands based upon a trait-based approach.

Description: Publication date: 15 January 2015 Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 418 Author(s): Travis Z. Wicks , Kaustubh Thirumalai , Timothy M. Shanahan , Christopher J. Bell δ 13 C records from vertebrate teeth offer an opportunity to gain insight into changes in past vegetation. Increasingly, teeth from small mammals are used for such purposes, but because their teeth grow rapidly, seasonal changes in vegetation are potentially a large source of variability in their carbon isotope composition, complicating interpretations of isotope data. To investigate the influence of seasonality on the stable isotope composition of fossil teeth, we constructed a Monte-Carlo-based model to simulate the effects of changes in the seasonal pattern of diet in leporid lagomorphs (rabbits and hares) on the distribution of δ 13 C values in random populations of leporid teeth from the Edwards Plateau in central Texas. Changes in mean-state, seasonal vegetation range, and relative season length manifest themselves in predictable ways through changes in the median, standard deviation, and skewness of simulated tooth δ 13 C populations, provided sufficient numbers of teeth are analyzed. This Monte Carlo model was applied to the interpretation of a 20,000 year record of leporid tooth δ 13 C values from Hall's Cave on the Edwards Plateau in central Texas. Populations of teeth from different climate intervals (e.g., the late Glacial, Younger Dryas, and the Holocene) display changes in tooth δ 13 C distributions that may reflect changes in seasonal vegetation. The inferred changes in seasonality of vegetation based upon our modeling are consistent with hypothesized climatic changes. These results indicate that small mammal teeth can potentially provide unique insights into climate and vegetation on seasonal and longer timescales that complement other approaches, but should be interpreted with a careful consideration of local conditions, taxon ecology and physiology, and the dominant timescales of isotope variability in a rigorous statistical framework.

Description: Publication date: 15 January 2015 Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 418 Author(s): Steven L. Wick , Thomas M. Lehman , Alyson A. Brink A theropod tooth assemblage from the lower shale member of the Aguja Formation in West Texas is part of a diverse microvertebrate fauna, designated the Lowerverse local fauna, of early Campanian age (c. 80–82 Ma). The fauna includes as many as nine distinct theropod taxa along with several indeterminate archosaurs and birds. Theropod tooth types (indeterminate tyrannosaurids, cf. Saurornitholestes , cf. Richardoestesia , cf. Paronychodon ) are similar to those found in the upper shale member of the Aguja, as well as in other Campanian theropod assemblages from western North America. However, the most abundant tooth morphotype is unique, and attributed to a new varanoid lizard with remarkably theropod-like dentition, herein designated Dryadissector shilleri (gen. et sp. nov.). The presence of many unique theropod tooth morphotypes in the Lowerverse local fauna suggests that there remains significant undiscovered diversity among small theropods in southern latitude faunas, and accords with recognition of distinct latitudinal biomes during Campanian time in western North America. Due to their similar dentition, small theropods, along with varanoid lizards, may have served similar ecological roles as competitive mesopredators in the Campanian tropical predator guild.

Description: Publication date: 15 January 2015 Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 418 Author(s): Crispin T.S. Little , Daniel Birgel , Adrian J. Boyce , J. Alistair Crame , Jane E. Francis , Steffen Kiel , Jörn Peckmann , Duncan Pirrie , Gavyn K. Rollinson , James D. Witts Fossil hydrocarbon seeps are present in latest Cretaceous (Maastrichtian) volcaniclastic shallow shelf sediments exposed on Snow Hill and Seymour Islands, James Ross Basin, Antarctica. The seeps occur in the Snow Hill Island Formation on Snow Hill Island and are manifest as large-sized, cement-rich carbonate bodies, containing abundant thyasirid bivalves and rarer ammonites and solemyid bivalves. These bodies have typical seep cement phases, with δ 13 C values between − 20.4 and − 10.7‰ and contain molecular fossils indicative of terrigenous organic material and the micro-organisms involved in the anaerobic oxidation of methane, including methanotrophic archaea and sulphate-reducing bacteria. On Seymour Island the seeps occur as micrite-cemented burrow systems in the López de Bertodano Formation and are associated with thyasirid, solemyid and lucinid bivalves, and background molluscan taxa. The cemented burrows also have typical seep cement phases, with δ 13 C values between − 58.0 and − 24.6‰. There is evidence from other data that hydrocarbon seepage was a common feature in the James Ross Basin throughout the Maastrichtian and into the Eocene. The Snow Hill and Seymour Island examples comprise the third known area of Maastrichtian hydrocarbon seepage. But compared to most other ancient and modern seep communities, the James Ross Basin seep fauna is of very low diversity, being dominated by infaunal bivalves, all of which probably had thiotrophic chemosymbionts, but which were unlikely to have been seep obligates. Absent from the James Ross Basin seep fauna are ‘typical’ obligate seep taxa from the Cretaceous and the Cenozoic. Reasons for this may have been temporal, palaeolatitudinal, palaeobathymetric, or palaeoecological.

Description: Publication date: 15 January 2015 Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 418 Author(s): Ashu Khosla , Karen Chin , Habib Alimohammadin , Debi Dutta A rich microbiota with distinctive plant fossils has been discovered in Type A morphotype coprolites from the Lameta Formation of Pisdura, in Maharashtra, India. Macerated fractions examined with scanning electron microscopy revealed seven ostracod taxa, ( ?Mongolianella sp., Cypridea ( Pseudocypridina ) sp., Cypridopsis sp., Eucypris sp., Gomphocythere sp., Gomphocythere paucisulcatus , and Paracypretta sp.), diatoms ( Aulacoseira sp.), a charophyte ( Microchara sp.), and sponge spicules. Abundant probable chrysophytes were also observed in thin sections of one of the coprolites. Most of the plant debris is unidentifiable, but recognizable tissues include gymnosperm tissues, a spore, cuticle, and leaf laminae replaced with silica. Chemical analyses reveal that the coprolites are phosphatic, with ~ 12.2 to 16.2 wt.% phosphorus. The microfossils support a Maastrichtian age and fluvio-lacustrine depositional conditions for the Lameta Formation at Pisdura. The unusual combination of a phosphatic composition with plant and microfossil dietary residues suggests that the ancient faecal producers were intentional or inadvertent omnivores.

Description: Publication date: 15 January 2015 Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 418 Author(s): A. Pictet , G. Delanoy , T. Adatte , J.E. Spangenberg , C. Baudouin , P. Boselli , M. Boselli , P. Kindler , K.B. Föllmi A stratigraphic and depositional model, constrained by biostratigraphy, geochemistry, total phosphorus contents, and bulk-rock mineralogy, is proposed for lower Aptian sediments from the Languedoc platform in Ardèche, SE France. The upper lower Aptian is documented by the Chabert Formation (upper Deshayesites forbesi Zone to upper Dufrenoyia dufrenoyi Subzone), deposited on a discontinuity surface on top of the Urgonian platform, recording a first emersion phase and consecutive drowning event. The Chabert Formation starts with the marly Violette Member, which passes into crinoidal limestone of the Rocherenard Member. The top of this member is associated with a second discontinuity, recording a further drowning phase, which is followed by the deposition of the glauconitic and partly phosphatic Picourel Member (upper Deshayesites grandis to upper Dufrenoyia dufrenoyi Subzone). A third erosive phase is documented by a phosphatic conglomerate (upper Dufrenoyia furcata Zone), which represents a lag deposit derived from underlying sediments. The formation of this conglomerate was associated with a substantial emersion phase. This emersion was followed by a drowning event reworking the phosphatic conglomerate into the base of the upper Aptian black marls (Frayol Formation). The carbon-isotope record shows a negative excursion which coincides with the onset of the early Aptian oceanic anoxic Selli episode (OAE 1a) in the middle/upper part of the Deshayesites forbesi Zone. Emersion phases were an important factor implied in the formation of the sequence boundaries, which were transformed into drowning unconformities during subsequent phases of significant transgressions. These phases were associated with the installation of higher trophic levels, transforming or impeding carbonate production. The first drowning phase preceded the onset of the Selli episode, suggesting that rapid sea-level change and associated environmental change were already an important element of the early Aptian before the major phase of environmental change during the Selli episode.