Facies architecture of the Stuttgart Formation (Schilfsandstein, Upper Triassic), central Germany, and its comparison with modern Ganga system, India

The Stuttgart Formation (Schilfsandstein) is approximately 50 m thick in Thuringia, representing deposition during the “Mid-Carnian Wet Intermezzo”. Stratigraphically it occurs between the Grabfeld and Weser formations, which formed under arid conditions. It comprises NNE-SSW-trending elongate, anastomosing channelized sand-rich bodies with erosional bases (channel belts) that are several kilometres wide and pass laterally into predominantly mudstones deposited in interfluve areas. The source area of these clastics was the uplifted Norwegian Caledonides. Muddy interfluve facies is dominant in exposures in Thuringia, Central Germany.The Lower Stuttgart Formation has an unconformable base that is locally overlain by metre-thick “Basal Beds”. These consist of grey mudstones and thin sandstones deposited under humid conditions in predominantly shallow brackish water environments after a marine ingression via the Eastern Carpathian/Upper Silesian Gate. The following 30-40 m-grey, fine-grained sandstones, siltstones and mudstones were deposited in fluvial environments in channel belts and interfluve areas under humid conditions. These are followed by predominantly reddish mudstones and sandstones of mainly fluvial origin, deposited under somewhat drier conditions with seasonal droughts. The Upper Stuttgart Formation may be more than 16 m thick; it comprises reddish and grey sandstones and mudstones that were mostly deposited in lake delta settings by recurring flash floods. During the deposition of this unit climate was weakly humid with less prominent seasonal draughts.The modern Ganga Plain of India is an analogue for the depositional setting of the Stuttgart Formation. Climatic conditions in Ganga Plain are humid monsoonal with seasonal droughts and roughly comparable with those interpreted for Mid-Carnian times in Germany. The sandy deposits of incised channel belts and channels and muddy deposits of interfluve areas in the Ganga Plain are comparable with the sandstone-dominated channelized facies and mudstone dominated interfluve facies of the Stuttgart Formation, respectively.     

Response of Carnian Pluvial Episode evidenced by organic carbon isotopic excursions from western Hubei,South China

We here report a high-resolution organic C-isotope record from terrestrial–marine transitional sediments of the Badong Formation in the Luojiagou section, Zigui Basin of Hubei Province, South China. Our organic carbon isotope (δ¹³C_org) profile, ranging from -21.2‰ to -26.2‰, shows four negative carbon-isotope shifts. We suggest that the sharpest negative carbon isotope excursion in the upper portion of the Badong Formation marks the main phase of the Carnian Pluvial Episode (CPE) in the basin, likely correlated with those in other depositional records of this time. The occurrence of the CPE in the Badong Formation would imply that the stratigraphic coverage of the Badong Formation might be prolonged to incorporate (at least part of) the Late Triassic Carnian stage. This result provides a potential case for understanding the CPE in continental–marine environments in the eastern Tethys realm, and is significant for exploring the palaeoclimate variation across the Late Triassic.     

孢粉信息函数在辽河断陷西部凹陷沙河街组古环境分析中的应用

为了加强含油气盆地的古环境和古气候研究,寻找古环境研究的多种途径,探索用孢粉信息函数半定量恢复古环境和古气候。孢粉是气候变化敏感的信息载体,气候适宜,孢粉信息函数值越高,而且在沉积过程中,从岸边到湖盆中心,随着水体加深,孢粉信息函数值逐渐降低。利用孢粉信息函数的这种变化规律,按<2.0、2.0—2.1、>2.1三个参数值,将辽河断陷西部凹陷沙河街组一段沉积时期的湖盆划分为半深湖、浅湖和滨浅湖环境。并依据沙河街组孢粉信息函数值从沙四段到沙一段呈现低(1.97)—高(2.12)—低(1.88)—高(2.28)的韵律性变化,判断古气候呈干热—潮湿—干热—潮湿的旋回性演变。西部凹陷沙河街组孢粉信息函数的变化规律与古气候演变有很好的响应,同时与盆地不同发育阶段的古地貌、古环境密切相关。因此,孢粉信息函数是重建古气候、古环境的有效手段之一,能弥补缺少大化石给含油气盆地沉积环境研究带来的不足。     

A delayed carbonate factory breakdown during the Tethyan-wide Carnian Pluvial Episode along the Cimmerian terranes (Taurus,Turkey)

This paper presents a detailed facies analysis and paleo-depth reconstruction of a latest Early Carnian platform drowning-sequence from the Anatolian terrane (Turkey, Taurus Mountains). A total of eight sedimentary microfacies zones were recorded. An open platform margin passes through a deeper shelf margin setting into a basinal environment influenced by more open-marine conditions. The analysis demonstrates an unexpected, pure carbonate depositional system through the so-called Carnian Pluvial Episode (CPE), which has previously been associated with dramatic climate changes throughout the Tethys region. One main finding, based on sedimentological and paleontological analyses, is a much later drowning of the carbonate platforms in Turkey than in other places. The termination of the Kartoz platform postdates the onset of the CPE in the western Tethys by one ammonite zone, corresponding to about 2 million years. The distinctly earlier demise of (north)western Tethyan carbonate platforms and reefs points to a diachrony of this event throughout the Tethys. The decline of carbonate productivity clearly occurs earlier at higher paleolatitudes and later in equatorial areas. Interpreting the CPE as the result of a global or at least Tethys-wide climatic event is therefore highly ambiguous. The described facies changes at Aşağiyaylabel probably mirror different coupling effects and, only minimally, the Tethyan-wide climate changes during the Carnian Pluvial Episode.     

Taxonomical and palaeoecological investigations of the chondrichthyan and osteichthyan fish remains from the Middle-Late Triassic deposits of the Villány Hills (Southern Hungary)

Two sites in the Villány Hills, Hungary, have yielded rich fish assemblages from Middle to Late Triassic shallow marine deposits. The collected material comes from the Ladinian Templomhegy Dolomite Member and from the Carnian Mészhegy Sandstone Formation. The ichthyofauna is composed of both chondrichthyans (Hybodontidae indet., Palaeobates angustissimus, ‘Polyacrodus’ sp., ?Lissodus sp.) and osteichthyans (Gyrolepis sp., Birgeria sp., and further indeterminate actinopterygians). Despite the large sample size, no remains of neoselachians have been found. The Ladinian Templomhegy Dolomite is dominated by durophagous hybodontiforms (Palaeobates angustissimus, ?Lissodus sp.), but the piscivorous hybodontid and the generalist ‘Polyacrodus’ sp. are missing, while in the fish fauna collected from the Carnian Mészhegy Formation indeterminate piscivorous hybodontids are the most common elements and durophagous forms are much less abundant. The dominance of piscivorous hybodontids in the Carnian Mészhegy Sandstone could be related to the global decrease of diversity of marine fish-eating reptiles (e.g., nothosaurs) or to a change of paleoenvironmental conditions. The present study improves our knowledge on the poorly known Triassic vertebrate faunas of the Tisza Mega-unit, which formed a segment of the passive Neotethys margin of the European Plate and shows an important example of a potential vertebrate faunal shift during the Middle to Late Triassic.     

Additional cricetid and dipodid rodent material from the Erden Obo section,Erlian Basin (Nei Mongol,China) and its biochronological implications

New cricetid (Cricetops dormitor, Eocricetodon sp., Eucricetodon cf. E. wangae, Pappocricetodon schaubi) and dipodid (Allosminthus gobiensis n. sp., Allosminthus ernos, Allosminthus uniconjugatus, Allosminthus cf. A. majusculus, Primisminthus shanghenus, Sinosminthus sp.) occurrences from the “Lower Red”, “Middle Red”, “Middle White” and “Upper White” beds of the Erden Obo section in Nei Mongol, China are reported. They are first discovered in these horizons. On the basis of the comparison of the rodent assemblages, we consider that the age of the “Upper White” beds is early Oligocene, the age of the “Middle Red” and “Middle White” beds is probable more similar to the age of late Eocene Houldjin Formation and lower part of Chaijiachong Formation, and the age of the “Lower Red” beds is correlative to the Sharamurunian. The diversity of ctenodactyloid, dipodid, and cricetid appears to change, and the turnover in rodent fauna possibly responded to the environmental and climate change towards the end of middle Eocene.     

Fossil coniferous wood from the Middle Jurassic of Liaoning Province, China

Silicified coniferous wood was collected from the Lanqi Formation (late Middle Jurassic in age) at Shebudaigou Village, Liaoning Province, China. Three taxa are identified, namely Pinoxylon dacotense Knowlton, Xenoxylon phyllocladoides Gothan, and Araucariopitys sp. Based on these new data, and those of other fossil plants reported previously from the same formation, we consider the climate during the deposition of the Lanqi Formation was subtropical, humid and seasonal. In this respect the Lanqi flora differs from the coeval Shimengou and Longmen floras from North China. The Longmen flora was deposited during more humid, subtropical conditions, while the Shimengou Formation indicates that the climate was warm temperate and dry. Our data would suggest that the Late Jurassic climatic pattern was initiated as early as the late Middle Jurassic.     

El Niño-Southern Oscillation modulates insect outbreaks in humid subtropical China: Evidences from tree rings and carbon isotopes

Insect outbreaks are key disturbances triggering decline episodes in humid subtropical evergreen forests in eastern China. However, their long-term variability and linkages to climate are still unclear largely due to the shortness of records reporting forest damage. A retrospective approach would improve our understanding of long-term outbreak variability and its dependence on climate and relevant atmospheric circulation patterns such as the El Niño-Southern Oscillation (ENSO). This study provides a dendrochronological reconstruction of Dendrolimus punctatus outbreaks affecting Pinus massoniana in humid subtropical eastern China. We used tree-ring width and carbon isotope data from sites where outbreaks were or not were reported for the past fifty years, here considered as host and non-host sites, respectively. The results showed that inter-annual changes in carbon isotope discrimination are more sensitive to outbreaks than changes in tree-ring width. Based on carbon isotopes, we inferred that photosynthetic rates increased as a compensatory mechanism in response to insect defoliation. We reconstructed eleven insect outbreaks since 1915, which corresponded to ENSO positive phases and below-average sea surface temperatures in the central and eastern tropical Pacific Ocean. These conditions correspond to “La Niña” episodes which induce hot and dry climate conditions across the study region and these may facilitate the occurrence of D. punctatus outbreaks.     

Foraminiferal biozonation,biostratigraphy and trans-basinal correlation of the Oligo-Miocene Qom Formation,Iran (northeastern margin of the Tethyan Seaway)

During the Rupelian–Burdigalian (early Oligocene–early Miocene), the Qom Formation was deposited along the northeastern margin of the Tethyan Seaway in the Sanandaj–Sirjan, Urumieh–Dokhtar, and Central Iran basins. The biostratigraphic data from a total of 1152 thin sections from 10 outcrop sections along over 1000 km of the Tethyan Seaway margin are presented. A larger benthic foraminiferal (LBF) biozonation, consisting of five biozones, is proposed for dating the Rupelian–Burdigalian Qom Formation. It is correlated with global planktonic zones, LBF zones, southeastern Asian “Letter Stages”, shallow benthic foraminiferal zones (SB-zones) of southern European basins, and newly revised zones of the Asmari Formation in southwestern Iran. This biozonation subdivides the Rupelian stage into “early Rupelian” and “late Rupelian”, based on the first appearances of lepidocyclinids in the latter one. The early Rupelian strata are characterized by the presence of Nummulites without lepidocyclinids which are reported merely from southwestern and southern Kashan, where the thickest Rupelian deposits of the Qom Formation are recorded. The basal layers of the Qom Formation in southeasternmost outcrops (northwestern Jazmurian Lake) are late Rupelian in age based on the co-occurrence of lepidocyclinids and Nummulites spp. By comparison of the well-documented transgression of the Tethyan Seaway over the Iranian plate (from southeast to northwest) and the limitation of all reported early Rupelian strata of the Qom Formation to southwestern and southern Kashan, the following scenarios can be supposed: 1) the oldest deposits could be deposited in southeastern Iran, but they have not been reported, yet; 2) during early Rupelian, there was a transgression from the Zagros Basin to southwestern and southern Kashan areas, then the transgression progressed both northwestward and southeastward.     

Carnian (Triassic) aridization on the Levant margin: evidence from the M1 member, Mohilla Formation, Makhtesh Ramon, south Israel

The Carnian Pluvial Event was followed by extreme aridity around the Mediterranean region, but the relationship between these climatic modes and the evaporite deposits of the north Arabian margin has not been established. The Mohilla Formation in Israel was deposited on the rifted Levant margin of the Neotethyan seaway during the Carnian (Late Triassic). The lowermost member, M1 (carbonate, shale, minor evaporite), records sea-level and climate change of the transition from open-marine deposits to the thick evaporite of the overlying M2 member. Field, petrographic and cathodoluminescence investigation of the M1 member exposed at Makhtesh Ramon, southern Israel, enabled tracking of changing paleoenvironments. The M1 member can be subdivided into six sea-level controlled sedimentary cycles, each terminating in subaerial exposure. Open-marine, lagoonal, and supratidal belts are represented, but environments become increasingly restricted upwards. Three of the exposure horizons are marked by well-developed early diagenetic features, including dissolution porosity and meteoric cements. These changing facies belts and the superposed diagenetic modes formed under an oscillating climate regime of three relatively humid episodes dominated by deposition of carbonate, alternating with evaporitic sediments indicating aridity. Deposition of the M1 member can be correlated with the transition in the western Tethys from the Carnian pluvial episode to aridity. This transition in the Levant region is characterized by an oscillatory climate that culminated in a thick evaporite unit from the extreme arid phase. The oscillations may be attributed to shifting global climate belts, overprinted by monsoonal strengthening and weakening, in the equatorial belt.     

New Permian tetrapod footprints and macroflora from Turkey (Çakraz Formation, northwestern Anatolia): Biostratigraphic and palaeoenvironmental implications

New tetrapod footprints belonging to the ichnogenus Hyloidichnus have been discovered in Turkey for the first time, in the lower part of the Çakraz Formation (Northwestern Anatolia) and together with macrofloral imprints of Annularia and Stigmaria. These discoveries confirm the Permian age of the fossiliferous red beds in which the coniferophyte Walchia was previously recorded. Based on the stratigraphic range of Annularia, Stigmaria and Hyloidichnus known elsewhere, a Cisuralian age is proposed for these beds. These new ichno- and macrofloral remains, together with the sedimentological data (mudcracks, rain drops) suggest the presence of captorhinid reptiles living in a palustrine floodplain environment, and under a warm, seasonal climate alternating between humid and relatively long dry seasons. These climatic conditions may have permitted the migration of these captorhinids through Laurasia during the Permian.     

Late Carnian (Tuvalian,Tropites dilleri zone) ostracods (Crustacea) from the Mufara Formation (Monte Scalpello,Central-Eastern Sicily,Italy)

Ostracod association from the Upper Triassic (Tropites dilleri zone of the Carnian stage) of the sedimentary succession (Mufara Formation) exposed along the east side of Monte Scalpello (Catenanuova, central eastern Sicily) has been studied for the first time. The specimens, silicified, are rare but well preserved and often consist of complete carapaces. They belong to eight families: Healdiidae, Cavellinidae, Bairdiidae, Acratiidae, Bythocyprididae, Pontocyprididae, Judahellidae, Glorianellidae. Twenty-three taxa have been listed; the family Bairdiidae is the most represented among all the others with fifteen species. Four species are new: Bairdia scaliae n. sp., Acratia maugerii n. sp., “Anchistrocheles” gemmellaroi n. sp. and Judahella? montanarii n. sp. Other species are left in open nomenclature because of the lack of specimens.     

A new ammonoid fauna from the Carnian (Upper Triassic) Kasimlar Formation of the Taurus Mountains (Anatolia,Turkey)

We describe a new ammonoid fauna from the Taurus Mountains of southern Turkey. The Carnian ammonoid fauna from A?a?iyaylabel is presented for the first time. Ammonoids were obtained from limestone to marl beds of an approximately 35‐m‐thick section, which presents the rare opportunity to investigate ammonoid faunas across the Lower–Upper Carnian boundary. Intense sampling near the village of A?a?iyaylabel led to the recognition of a new Lower Carnian (Julian 2) to Upper Carnian (Tuvalian 1) ammonoid fauna from the Kasimlar Formation. The genus Kasimlarceltites gen. nov. is reported for the first time from the Taurus Mountains, which represents the main faunal element and occurs as huge mass occurrence (n ? 1 million). Kasimlarceltites krystyni gen. et sp. nov., Klipsteinia disciformis sp. nov. and Anasirenites crassicrenulatus sp. nov. occur within the Lower Carnian Carbonate member (Units A–B) of the Kasimlar Formation from the Taurus Platform Units. Ammonoids described from the marls of the Tuvalian Marlstone member were deposited during a major, Tethyan‐wide climate crisis – the so‐called Carnian crisis – characterized by a demise of carbonate platforms. Based on the biostratigraphic relevance of certain ammonoid taxa described herein, the age of the analysed parts of the Kasimlar Formation is Julian 2 to Tuvalian 1. The discovery of the new ammonoid assemblages from A?a?iyaylabel substantiates the significance of Upper Triassic faunas within the Taurus Mountains and facilitates the correlation with faunal assemblages from other regions in the Tethyan Realm. The ammonoid fauna and facies indicate a general deepening from open‐platform margins, over deeper shelf settings down to an open marine‐influenced basinal environment. The tentative habitat for Kasimlarceltites gen. nov. is a shallow platform environment to upper mid‐ramp.     

新疆车排子地区孢粉植物群与古气候

通过对新疆准噶尔盆地西北缘车排子地区多口探井样品分析,见丰富的孢粉化石,建立了PiceapollisPodocarpidites-Tsugaepollenites,Parajunggarsporites-Piceaepollenites,Protohaploxypinus-Striatoabieites-Hamiapollenites三个孢粉组合。根据孢粉母体植物形态和生态特征、干湿度环境和气候环境,对其孢粉植物群反映的植被类型、干湿度类型和气候带类型进行了划分,认为晚中新世孢粉植被类型为针叶林,所处的气候环境为湿润的暖温带;早白垩世孢粉植被类型为混交林,所处的气候环境为湿润的亚热带-暖温带;晚石炭世时期其植被面貌是以阔叶植物为主,所处的气候环境为半干旱的暖温带。     

广西凤山、西林等地中三叠统上部双壳类分带研究*

讨论广西西部中三叠统上部的双壳类生物地层序列,建立5个化石带;并附述黔南和滇东南晚三叠世1个双壳类带.这些带自下而上为:(1) Daonella (Longidaonella) producta-D. americana 带,属晚安尼早中期;(2) D. moussoni 高峰带,属晚安尼晚期;(3) D. rieberi-D. indica 带,属早拉丁期;(4) D. kotoi-D. jilongensis 带,属晚拉丁早期;(5) Halobia subcomata-D. varifurcata带,属晚拉丁晚期;(6) H. rugosoides-H. bifurcata 带,属早卡尼期.文内简要描述了各带的主要标志化石23种.     

Multi-proxy paleosol evidence for middle and late Triassic climate trends in eastern Utah

Prior investigations suggest that alluvial lowlands of Pangea in the southwestern U.S.A. during the middle to late Triassic experienced an arid to semiarid climate with significant seasonality. Our investigation finds evidence for a global pluvial episode from paleosols in the middle to late Triassic section of eastern Utah. Multi-proxy paleosol evidence is used to quantify rainfall amounts, ambient temperatures and atmospheric CO₂ concentrations and infer associated plant formations related to ecosystem persistence. Rainfall estimates are derived from geochemical molecular weathering ratios; temperature and atmospheric CO₂ levels from stable oxygen and carbon isotopes of pedogenic carbonate, respectively; and ecosystem reconstruction by a combination of climate indexes and paleosol characteristics. Eight pedotypes were identified and include poorly drained aquic Entisols (Fisher), well-drained non-aquic Entisols (Salt Valley), calcic Aridisols (Castle Valley), calcic Inceptisols (Moab), cambic (Ute) and calcic (La Sal) Vertisols, dystric Inceptisols (Kokopeli), and argillic Alfisols (Slickrock). The middle Triassic Moenkopi Formation (Anisian) was dominated by Castle Valley paleosols with mean annual rainfall between 300 and 400 mm and mean annual temperature between 13 and 23 °C (mesic to hyperthermic). Based on these climate indexes and root traces, the associated plant formation was most likely desert shrub or dry woodland. The lower Chinle Formation (Carnian) contains a succession of Ute and La Sal paleosols that changed up-section to Kokopeli, Fisher and Slickrock paleosols. In accordance with geochemical and isotopic signatures from these pedotypes, rainfall amounts initially increased to between 700 and 900 mm, and then to between 1300 and 1400 mm. Temperatures estimated from the La Sal paleosol are approximately 18 °C (thermic) at this time. The lower Chinle marks a transition from dry woodland to open forest that appears to correlate with the formation of the Petrified Forest Member in Arizona. The upper Chinle Formation (Carnian-Norian) reveals a return to semiarid to subhumid conditions and the formation of Castle Valley, Moab and Salt Valley paleosols, all of which appear to have supported desert shrub or dry woodlands. Rainfall amounts decreased to between 400 and 600 mm with temperatures eventually increasing to 29 °C (hyperthermic). Using the paleosol isotopic barometer, atmospheric CO₂ estimates generally correlate with other proxy for the Triassic. The well-developed Alfisols and noncalcareous Inceptisols identified during the Carnian of the lower Chinle correlate with a previously identified global pluvial episode based on sedimentological and marine isotopic evidence, possibly in response to rifting of Pangea. It should not be assumed that the middle to late Triassic in continental alluvial lowlands supported a uniform, semiarid to arid climate, with strong seasonality.     

Variation in the Ichnofauna of the Collio Formation (Lower Permian) in the South-Alpine Region (Northern Italy)

In the Collio Formation (Lower Permian) of the South-Apine region (North Italy) paleobiodiversity consists of tetrapod footprints, invertebrate traces and rarer plants, and is characterized by an absolute poverty of taxa that becomes more acute from the lower to the upper part of the Collio Formation. Regionally, the drop in diversity can be explained by joint tectonic and climatic change; humid evergreen environments became mainly dry. Examination of ichnofossil distribution supports this hypothesis.     

Pedogenesis and paleoclimatic implications of the Chamberlain Pass Formation, Basal White River Group, Badlands of South Dakota

The Chamberlain Pass Formation is a new lithostratigraphic unit representing the first phase of deposition of the Paleogene White River Group in western South Dakota. Analysis of pedogenic features within the channel and overbank deposits of the Chamberlain Pass Formation allows for a refinement of Middle to Late Eocene paleoclimates of this area. Pedogenic features within distal overbank deposits of the Chamberlain Pass Formation have long been recognized and classified as the Interior Paleosol Series (Retallack, 1983). Previous interpretations held that distal overbank sediments and soils of this time were deposited and formed under humid, acidic environments. This research demonstrates that, while this interpretation is correct, soils of the Chamberlain Pass Formation were also subjected to periods of dryness. Pedogenic features preserved within the channel sandstone and proximal overbank deposits (which include root traces, peds, cutans, glaebules, Bt, Btc and Bc horizons, silcretes and altered detrial sandstone mineralogy) suggest the formation of Aqualfs, Aquults and Durixerults. Soils appear to have been acidic to slightly alkaline, oxidizing and moderately-to well-drained, depending upon the physiographic position of the soil and the prevailing climate at the time of formation. Soils formed within the channel and proximal overbank deposits represent a new soil series, herein designated as the Weta Paleosol Series. The Weta and Interior Paleosol Series have a catenary soil relationship, based on differences in parent material and soil moisture conditions.

Middle to Late Eocene paleoclimate appears to have fluctuated between humid and dry conditions. Within the Weta Paleosol Series, soils formed within one physiographic and climatic regime were successively overprinted by pedogenic features of soils formed during later periods under different physiographic and climatic regimes. This has resulted in the presence of humid climate soil pedorelicts in dry climate soils, dry climate pedorelicts within humid climate soils and the overlapping of various physiogrpahically controlled pedogenic processes as baselevels changed. Sediments of similar pedostratigraphic and lithostratigraphic arrangement can be found in Nebraska, northern South Dakota and North Dakota. The recognition of these similar sediments in different basins across the northern Great Plains may allow for an increased understanding of regional tectonic, depositional, climatic and geomorphic events during the Paleogene.     

Conservation status of the only representative of infraorder Mygalomorphae (Araneae) in cultivated regions of Central Europe

Purse-web spiders Atypus spp. (Araneae: Atypidae) are the only representatives of the archaic spider infraorder Mygalomorphae in the Central European fauna. These burrow-dwelling spiders are red-listed in all Central European countries. Atypus muralis occurs on relics of continental steppes, Atypus piceus on dry submediterranean grassland and dry herb-rich forest fringes, while Atypus affinis inhabits sparse dwarf dry forests, usually those dominated by oaks. Long-term sustainability of their habitats in the relatively humid Central European climate was maintained by grazing. Since the 1950s, pasturing was terminated across most of Central Europe, which led to immediate overgrowth of pastures by aggressive grasses and woody plants. Grazing was later reinstated in some reserves, but in cases of poorly controlled grazing intensity, footsteps had immediate detrimental effects on the residual populations of purse-web spiders and other invertebrates. Therefore, grazing intensity needs to be regulated, considering its double-edge effects on the biota of xerothermophilic habitats. Nests of European Atypus species have never been found in habitats subject to recent or even regular distribution. Therefore, they may serve as reliable indicators of well preserved xerothermic habitats. Their nests are easy to detect, and the European Atypus spiders can be utilized as model species for monitoring impacts of conservation management. Monitoring population dynamics of Atypus requires establishing permanent study plots of uniform size, documentation of vegetation by phytocenological relevé, counting their density (number of purse-webs found in the plot) and age structure (diameter of purse webs).     

A Basal Sauropodomorph (Dinosauria: Saurischia) from the Ischigualasto Formation (Triassic,Carnian) and the Early Evolution of Sauropodomorpha

Background

The earliest dinosaurs are from the early Late Triassic (Carnian) of South America. By the Carnian the main clades Saurischia and Ornithischia were already established, and the presence of the most primitive known sauropodomorph Saturnalia suggests also that Saurischia had already diverged into Theropoda and Sauropodomorpha. Knowledge of Carnian sauropodomorphs has been restricted to this single species.

Methodology/Principal Findings

We describe a new small sauropodomorph dinosaur from the Ischigualsto Formation (Carnian) in northwest Argentina, Panphagia protos gen. et sp. nov., on the basis of a partial skeleton. The genus and species are characterized by an anteroposteriorly elongated fossa on the base of the anteroventral process of the nasal; wide lateral flange on the quadrate with a large foramen; deep groove on the lateral surface of the lower jaw surrounded by prominent dorsal and ventral ridges; bifurcated posteroventral process of the dentary; long retroarticular process transversally wider than the articular area for the quadrate; oval scars on the lateral surface of the posterior border of the centra of cervical vertebrae; distinct prominences on the neural arc of the anterior cervical vertebra; distal end of the scapular blade nearly three times wider than the neck; scapular blade with an expanded posterodistal corner; and medial lamina of brevis fossa twice as wide as the iliac spine.

Conclusions/Significance

We regard Panphagia as the most basal sauropodomorph, which shares the following apomorphies with Saturnalia and more derived sauropodomorphs: basally constricted crowns; lanceolate crowns; teeth of the anterior quarter of the dentary higher than the others; and short posterolateral flange of distal tibia. The presence of Panphagia at the base of the early Carnian Ischigualasto Formation suggests an earlier origin of Sauropodomorpha during the Middle Triassic.