Stratigraphy,facies and synsedimentary tectonics in the Jurassic Rosso Ammonitico Veronese (Altopiano di Asiago,NE Italy)

Summary The red, pelagic limestones of the Rosso Ammonitico Veronese (Upper Bajocian-Tithonian) of the Altopiano di Asiago area can be subdivided into eight facies. They differ from each other in structure (bedding style, presence and type of nodularity) and texture (nature of components, grain-vs mud-support, compactional features). Several discontinuities could be recognized, based on sedimentological or biostratigraphic evidence. In the context of a drowned platform, where sediments essentially consist of skeletal remains of both planktonic and benthic organism, the different facies are interpreted as reflecting a varying influence of currents on the winnowing of micrite and on triggering early cementation. Early cementation in turn, controlled the patterns of bioturbation and the response of sediments to later compaction and pressure-dissolution. At times, microbial mats, of unidentified nature, were important in trapping and binding sediment, giving rise to early lithified nodules and layers of stromatolitic aspect. The Rosso Ammonitico Veronese can be subdivided into three units: lower Rosso Ammonitico (RAI: Upper Bajocian-Lower Callovian), middle Rosso Ammonitico (RAM: Upper Callovian-Middle Oxfordian), and upper Rosso Ammonitico (RAS: Lower Kimmeridgian-Tithonian). Frequent ammonite moulds allow the precise dating of the base and top of each unit, and the documentation of facies heteropies and hiatusses in the more fossiliferous RAS. The lower unit (RAM) is massive and essentially nodular; the middle unit (RAM) is well bedded, non-nodular, and cherty; the upper unit (RAS) is richer in clay and typically nodular. The RAI and the RAS are present everywhere, though significant facies and thickness changes affect particularly the RAS; the RAM is much more variable, ranging from 0 to 10 metres. These variations, that may be gradual or abrupt, are inter-preted as the result of Middle-Late Callovian block-faulting which generated an irregular sea floor topography where the swells were more exposed to currents that continuously removed sediments, inducing long-lasting periods of nondeposition. Sediments preferentially accumulated in the adjacent lows. A confirmation of this hypothesis is provided by evidence of synsedimentary tectonics, described for the first time in the Rosso Ammonitico Veronese. Neptunian dykes, both vertical and horizontal, are developed at the top of the RAI and are filled with laminated sediments or collapse breccias. Glides of metre-size blocks and slumps are present at the top of the RAI and at the base of the RAM, respectively. Cm-thick layers of mud supported breccias are intercalated in the upper part of the RAI and within the RAM: they are interpreted as seismites. All these features document a tensional regime that generated fractures in more or less lithified sediments and failure along steep fault scarps or gently dipping slopes of tilted fault blocks. Recognition of this Callovian-Oxfordian tectonic activity shows that, after the Bajocian drowning, the Trento Plateau did not simply experience a uniform and general foundering: a small-scale block-faulting was still active and affected the pattern of facies distribution.     

Sur l’origine bactérienne et fongique de la pigmentation de l’Ammonitico Rosso (Jurassique, région de Vérone, Italie du nord)

Fourteen sections in the Ammonitico Rosso Veronese (Callovian to Tithonian, Trento altipiano) disclose the presence of diverse facies ranging from pelagic to outer platform. In spite of this diversity, red limestones are present at different levels. Many microfacies are similar to those observed in other Paleozoic and Mesozoic red carbonates with an abundance of hematitic bioconstructions. We therefore postulate that the origin of the pigmentation is similar in all the studied cases and due to the activity of iron-oxidizing bacteria. Nevertheless, 2 notable differences are observed: the presence in the Ammonitico Rosso of manganese and the existence of in situ bacterial-fungal mats in the matrix. These “algal” mats can represent up to 20% of the sediment. Their excellent preservation (absence of packing down or crushing) is due to the slow sedimentation rate of the pelagic sediments or of the hardgrounds.     

Die Fossilfcührung des erdfalls von nieheim (se-westfalen) und seine bedeutung für die paläogeographie imcampan und miozän das nordwestdeutsche tertiärbecken,nr. 27

A landfall in the east Westphalian-Lippean area contains a breccia of Keuper, Liassic and Miocene (marine Reinbekian) sediments. Within the Reinbekian sediments calcareous nannoplankton, diversified foraminiferal assemblages, ostracods, lamellibranchiates and gastropods, including a new subspecies ofAlvania (A.) curta, were found. Furthermore, foraminiferal and calcareous nannoplankton assemblages of Santonian to Campanian age are present. On the basis of these occurrences, the paleogeographic conception of the past coastline of the Westphalian Upper Cretaceous sea as well as of the southern extension of the boreal Middle Miocene sea can be revised. A gulf, stretching to the South, may have connected the North Sea basin with the basin of Mayence and the upper Rhine valley through the Hessian depression for certain periods during the Middle Miocene.     

Evolution of pelagic swells from hardground analysis (Bathonian–Oxfordian, Eastern External Subbetic, southern Spain)

The Middle Bathonian to Middle Oxfordian interval in the Eastern External Subbetic (Betic Cordillera, SE Spain) is characterized by Ammonitico Rosso facies including various stratigraphic breaks. Five hardground-bounded units are recognized in relation to hiatuses in the ammonite record at the following stratigraphic boundaries: Hg1 (Lower–Middle Bathonian), Hg2 (Middle–Upper Bathonian), Hg3 (Lower–Middle Callovian), Hg4 (Middle–Upper Callovian), and Hg5 (Callovian–Oxfordian). Interesting features of these hardgrounds include their microfacies, ferruginous crusts and macro-oncoids, taphonomy of macroinvertebrates, trace fossils, neptunian dykes, and the hiatuses associated with each of them. The main hardgrounds (Hg1, Hg2, and Hg5) contain trace fossils of the Cruziana and Trypanites ichnofacies as well as abundant fossil macroinvertebrates with taphonomic features evidencing corrasion, early diagenesis, and reworking, indicating substrate evolution from softground to hardground. Neptunian dykes affected the trace fossils and ammonoid moulds, and their walls and the hardground surfaces were colonized by ferruginous microbial crusts. These features are characteristic of the External Subbetic pelagic swells, where the absence of sedimentation, sediment bypassing and erosion, and early diagenesis during relative sea-level falls produced hardgrounds. The neptunian dykes are indicative of tectonic activity in the areas of pelagic swells. Ferruginous crusts and macro-oncoids developed only on hardground surfaces and neptunian dykes walls prior to deposition of condensed bioclastic beds, which are interpreted as the first deposits after hardground development and are related to the onset of transgression. The varying ranges of the gaps as well as lateral facies changes are related to different local paleobathymetry controlled by the activity of listric faults.     

Biostratinomy and palaeoecology of the cassian formation (Triassic) of the Southern Alps

The sediments forming the Cassian Formation (Middle—Upper Triassic) of the Central Dolomites represent the following environments: back-reef areas, shallow marginal basins, slope, and central basin. In each of these major environments faunal assemblages were found whose composition, mode of preservation and occurrence proved to be characteristics. In the back-reef areas, algal/foraminifera- and calcareous sponge/coral-patch reefs with a highly diverse fauna of frame-builders and reef-dwellers, in some localities excellently preserved, form the most conspicuous feature. In the shallow marginal basins autochthonous algal meadow/soft-bottom associations dominated by gastropods and deposit-feeding bivalves prevail. Slope deposits do not contain any autochthonous associations but either remains of pelagic faunas or transported faunal elements of shallow-water origin in the form of Cipit boulders (subaerially cemented parts from the outer edge of the carbonate platforms), worn Pachycardia rugosa-dominated, or echinoderm debris-dominated assemblages. Sediments of the central basin lack benthic faunas but contains pelagic assemblages of low diversity dominated by Daonella, Posidonia, and some ammonites.     

Sedimentary environment of Devonian pelagic limestones in the Southern Alps

Primary sedimentary structures combined with the geometry of Devonian and Lower Palaeozoic lithosomes in the Southern Alps (Austria and Italy) suggest many doubts about the published environmental and bathymetric interpretation of some Lower to Middle Devonian pelagic nodular limestones as 'deep-water' abyssal deposits. Every graded bed is not necessarily aturbidite; a single or some turbiditic beds are not necessarily deep-water or abyssal deposits; carbonate dissolution does not necessarily take place only below the carbonate compensation depth (CCD). Data show that graded allodapic beds, like those of the Lower to Middle Devonian of the Alps, may have been deposited as storm layers at a depth not exceeding some hundreds of metres. Accordingly the margins between Lower Devonian shallow-water platform and basins were characterized by low gradient and transitional sedimentary conditions. They became very steep only at the Devonian–Carboniferous transition because of synsedimentary block faulting.     

Contribution of calcareous nannoplankton to carbonate deposition: a new approach applied to the Lower Jurassic of central Italy

The Upper Pliensbachian–Lower Toarcian Somma section (Central Italy), which displays alternation of limestone–marl lithotypes, was investigated for its calcareous nannofossil and CaCO₃ contents. In order to evaluate the contribution of calcareous phytoplankton to the carbonate fraction of rocks a new method was applied combining a recently developed technique for nannofossil absolute quantification and measurements of nannofossil size. Our study suggests that nannofossils did not produce the bulk of carbonate mud in the studied section, although they contribute to different extents to the pelagic carbonate fraction. The contribution of both coccoliths and (mainly) the Incertae sedis Schizosphaerella to the carbonate fraction was important only in periods of reduced accumulation rates and/or during clay deposition. The highest estimated carbonate production by nannofossils in the studied section is around 83% of the total carbonate content, but in a sample containing only 12.8 wt% CaCO₃. The observed limestone–marl alternations therefore result from cyclical export of carbonate mud from the shallow Latium–Abruzzi carbonate platform to the Umbria–Marche Basin and, only subordinately, from changes in nannoplankton productivity.     

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.     

Late Triassic, Early and Middle Jurassic Radiolaria from ferromanganese-chert ‘nodules’ (Angelokastron, Argolis, Greece): evidence for prolonged radiolarite sedimentation in the Maliac-Vardar Ocean

In the Argolis, the Basal Sequence, constituting the eastern Pelagonian margin which bordered the Maliac-Vardar oceanic domain, includes shallow-water carbonates of Late Triassic-Early Jurassic, condensed pelagic limestones of Early-Middle Jurassic, radiolarian cherts of late Middle-Late Jurassic age and siliceous mudstones and sandstones rich in ophiolite fragments. Up-section, coarse breccias, including clasts of boninites derived from the ophiolite obducted onto the Pelagonian margin in Late Jurassic times crop out. Near Angelokastron a small quarry exposes pervasively sheared dark reddish-brown, radiolarian-bearing cherty shales with disrupted fragments of chert and chert nodules impregnated by ferro-manganese oxides. These shales occur in the footwall of a thrust bringing them into contact with the Pantokrator Limestone of the Basal Sequence. We collected more than 30 samples of the chert fragments and the shaly matrix. Thirteen nodules and one matrix sample yielded determinable radiolarians. Low to non-detectable concentrations of trace metals such as Co, Cr, Cu, Ni, Zn, and Pb indicate a hydrothermal origin of the ferro-manganese mineralization. The radiolarian taxa found indicate four age groups for the nodules that are embedded in the siliceous shale matrix that yielded a Middle Jurassic age (middle Bathonian). The first group includes a nodule of Late Triassic age (late Norian to Rhaetian); the second group nodules of Early Jurassic age (late early to late Pliensbachian and probably middle-late Toarcian); the third group nodules of early Middle Jurassic age (Aalenian–Bajocian); the last group finally includes nodules of late Middle Jurassic age (Bajocian–Bathonian). The presence of Upper Triassic to Middle Jurassic Mn-impregnated chert nodules in a Middle Jurassic matrix indicates a deep oceanic environment of deposition outside the Pelagonian realm (easternmost Adria Plate), which at that time was a shallow-water carbonate platform with a thin pelagic limestone cover. The chert nodules are with all certainty derived from the oceanic Maliac-Vardar domain and were, together with their host formation, tectonically emplaced onto the Pelagonian margin. We speculate that these nodules, more lithified than their matrix, were exhumed on the slope of an intra-oceanic accretionary wedge and were redeposited in the Middle Jurassic siliceous mudstones on the floor of the subducting Maliac-Vardar Ocean.     

Onset of significant pelagic carbonate accumulation after the Carnian Pluvial Event (CPE) in the western Tethys

Abundant calcispheres occur in Upper Carnian and Norian hemipelagic limestone successions of the Southern Apennines and Sicily. They exhibit a variety of morphologies that were investigated with optical and scanning electron microscopy (SEM). The most common morphology is that of a full solid sphere of radiaxial calcite crystals, 20–22 μm in diameter on average, with or without a minor hollow in the center. Smaller forms may be clusters of sub-micron crystals, only rarely disposed as to form a spherical test with a diameter of 10 μm or less. Larger forms are similar to small forms (clusters or spheres of sub-micron crystals) with an epitaxial calcite overgrowth. The taxonomic attribution of these calcispheres is uncertain, mostly because of their poor preservation, but a comparison is possible with some Mesozoic calcispheres attributed to calcareous dinocysts. The amount of epitaxial overgrowth is variable, but in most cases much larger than the original sphere. This prevents a significant evaluation of the contribution of calcispheres to carbonate pelagic sedimentation by point counting in thin-section. However, it can be shown that calcispheres become abundant only after a major climatic perturbation dated at the end of the Early Carnian, known as the Carnian Pluvial Event (CPE). This event involved a strong and prolonged enhancement of the hydrological cycle, with consequent supply of excess hydrogen carbonate to the oceans and increased seawater alkalinity. Although calcispheres of this type are known at least from the Middle Triassic, it is only shortly after the CPE that they become abundant, and the first common occurrence of calcareous nannoplankton in the western Tethys is thus Late Carnian in age.     

Middle Miocene warm-temperate carbonates of Central Paratethys (Mt. Zrinska Gora, Croatia): paleoenvironmental reconstruction based on bryozoans, coralline red algae, foraminifera, and calcareous nannoplankton

Carbonate deposits from Zrin in the Mt. Zrinska Gora were deposited in the SW part of the Central Paratethys Sea during the Middle Badenian (Middle Miocene). The studied section contains a rich fossil community of non-geniculate coralline red algae (Subfamily Melobesioideae), bryozoans, benthic and planktonic foraminifera, echinoderms, ostracods, molluscs, and calcareous nannoplankton. Based on lithological variations and changes in the biogenic components, four facies associations (FA) are distinguished. Their distribution points to skeletal production and sedimentation on a middle to proximal outer carbonate ramp. The main lithological feature of the section is an alternation of two lithofacies: fully lithified grainstone–rudstone and packstone, and semi-lithified rudstone–floatstone with a carbonate sandy matrix. Depositional environments on the ramp were periodically influenced by minor high-frequency sea-level changes and/or changes of hydrodynamic conditions, which are suggested as the driving mechanisms causing the alternation of the two lithofacies. Vertically in the succession, the two lithofacies alternate to give three thinning- and fining-upward units. The lower part of each unit is formed of a rhodolith and coralline algal FA, which passes upwards into a bryozoan-coralline algal FA and/or FA of bioclastic packstone-grainstone. Based on the vertical upward change in FAs, each unit can be interpreted as a deepening-upward sequence. Patterns in the relative abundance of bryozoan colony growth form (vinculariiform, cellariiform, adeoniform, membraniporiform, celleporiform, and reteporiform), size and abundance of rhodoliths and coralline branches, and benthic foraminifera are interpreted by comparison with data from modern and fossil environments. Based on these data, a water depth range for each FA is interpreted, providing evidence of low-frequency relative sea-level changes. It is hypothesized that relative sea-level fluctuated in the water depth range from 30 to 80 m, and in the uppermost part of the section, rich in planktonic foraminifera and calcareous nannoplankton, possibly deeper. Causes of the low-frequency relative sea-level fluctuations and the general deepening trend observed within the succession cannot be interpreted based on one section; however, they may be related to the subsidence of the depositional basin. The benthic biotic communities are a vertical alternation of rhodalgal and bryorhodalgal associations, and this is attributed to relative sea-level fluctuations. These biotic associations gave rise to warm-temperate carbonates of the Middle Badenian N9 planktonic Zone (Orbulina suturalis, O. universa) and NN4–NN5 nannoplankton Zones (Sphenolithus heteromorphus).     

Phytoplankton-stratigraphy from neogene,marine depositions near ierapetra,crete, Greece

The fossil calcareous and siliceous phytoplankton occurring in the Neogene of the island of Crete — Greece — (South Aegean island arc), was studied using normal ligntmicroscopic techniques. By this method it was possible to identify 13 species of the silicoflagellates and 22 species of the diatoms, which are investigated in this work for their stratigraphical range. The nannoplankton assemblages along the locality from Tsikalaria belong to theDistephanus boliviensis and theDiscoaster tamalis zone (early Upper Pliocene).     

The significance ofSaccocoma-calciturbidites for the analysis of the Polish epicontinental late Jurassic Basin: An example from the Southern Cracow-Wielun Upland (Poland)

Summary In the top section of the Upper Jurassic profile in the S part of the Cracow-Wielun upland there occur deposits with numerous fragments of the plantonic crinoidsSaccocoma. Sedimentary structures indicate that these deposits are calciturbidites with domination of the redeposited pelagic material. TheSaccocoma-calciturbidites rest on the slope beds of Oxfordian cyanobacterial-sponge carbonate buildups formed in the Polish epicontinental basin, bordering the Tethys ocean in the north. The occurrence of the planktonicSaccocoma seems to be connected with a short deepening the S part of the Polish epicontinental basin in the Late Jurassic. This deepening caused the change within biocoenoses thriving in carbonate buildups and was mainly expressed in reducingTubiphytes. ‘Tubiphytes-reefs’, representing the last stage in the development of the carbonate buildups in the S part of the Cracow-Wielun upland, marked the most shallow sedimentation environment. With deepending of the basin,Tubiphytes and other benthonic forms disappeared, and, simultaneously, the dominant fauna became planktonic. The abundance of planktonic crinoidsSaccocoma (=Lombardia), as well as the presence of planktonic foraminifers, nannoplankton cf.Schizosphaerella, coccoliths and radiolarians indicates a pelagic, open-sea depositional environment. TheSaccocoma-dominated sediments, which had been primarily deposited from a suspension on a sea floor with a distinct relief, became subsequently transported by turbidity currents. A limited extent and thickness of theSaccocoma-calciturbidites was caused by a relatively small amount of the primary material which could be transferred by the turbidity currents because the period of pelagic sedimentation was short. TheSaccocoma-calciturbidites indicate a distinct shift in conditions of sedimentation resulting from over-regional changes and, despite the lack of index fossils, seem to represent a local lithostratigraphic horizon. These sediments probably mark a sedimentation event which caused a minor levelling of the sea floor relief. Then, after a sedimentation break, wide-spread destruction of the tops of carbonate buildups and formation of debris flows in the shallowing Late Jurassic sea took place. TheSaccocoma-calciturbidites in the S part of the Cracow-Wielun upland can be found near edges of horsts. This suggests that the foundations of these horsts are probably of sedimentary origin, dating back at least to the Late Jurassic. TheSaccocoma-calciturbidites in the S part of the Polish epicontinental basin seem to result from local, synsedimentary tectonic movements, which probably reflect over-regional events on the one hand, and oscillations of the sea level-on the other.     

Middle Triassic basin evolution and stratigraphy in the Carnic Alps (Austria)

Summary A local intraplatform basin developed in the Gartnerkofel-Zielkofel area of the Carnic Alps (southern Carinthia, Austria) during the Middle Triassic (Ladinian). This basin was filled with a transgressive basinal sequence composed of the Uggowitz Formation and overlying Buchenstein Formation. At the northwestern slope of the Gartnerkofel, the platform carbonates of the Schlern Dolomite interfinger with the Buchenstein Formation, causing the formation of two depositional sequences. The Uggowitz Formation consists of the Uggowitz Breccia and the Kühweg Member. Sediments of the Uggowitz Breccia were formed by different types of gravity induced processes. The Kühweg Member is a thin sequence of silt-and fine-grained sandstones which were deposited in a slope to basin margin environment by turbidity currents. The overlying Buchenstein Formation consists of hemipelagic to pelagic limestones of Fassanian age with intercalated pyroclastic rocks (Pietra verde). Nodular limestones were deposited under slow rates of accumulation during a relative sea-level highstand. The uppermost Buchenstein Formation is composed of hemipelagic limestone beds with intercalated graded calcarenites and breccias of platform-derived debris, showing characteristics features of a fore-reef slope of the prograding Schlern Dolomite. Uggowitz Formation and basal Buchenstein Formation are interpreted as a transgressive systems tract, nodular limestones from the middle part of the Buchenstein Formation mark an early highstand systems tract, forereef slope sediments of the upper Buchenstein Formation formed during the beginning regression of a late highstand systems tract, the basal part of the overlying Schlern Dolomite probably reflects a lowstand systems tract. The intercalated bedded limestone facies within the Schlern Dolomite is characterized by large, platform derived blocks, slump structures, breccia beds, graded calcarenites and hemipelagic limestones indicating a forereef slope environent. This intercalated facies belongs to the Buchenstein Formation and interfingers with the Schlern Dolomite. Conodonts from this intercalated slope facies point to Late Fassanian age. Therefore, the two Middle Triassic depositional sequences of the Gartnerkofel area can be correlated with the depositional sequences ‘Ladinian 1’ and ‘Ladinian 2’ of the Dolomites, proposed byDe Zanche et al. (1993). A brief comparison with the basinal sequences of similar age of the karawanken Mountains and the Carnia is presented.     

Triassic reefs in Slovenia

The paper deals with the distribution, paleogeography, age and biota of Triassic reefs in Slovenia. Most of these reefs have not been studied in detail up to now, but the paleographical distributional pattern can be outlined (Figs. 1 and 2). Triassic reefs are known from Central and Northern Slovenia, predominantly occurring at the margins of the “Slovenian trough” (which separates the northern Julian Platform and the southern Dinaric Platform) and at the margins of an intraplatform trough within the Julian platform. Reef growth started in the Ladinian and Cordevolian and continued (with interruptions during the Upper Carnian ?) to the Norian and Rhaetian. Anisian environments are characterized by the predominance of algal mats and dasycladacean algae. Cordevolian patch reefs as well as Norian and Rhaetian reefs were built during the Late Triassic by calcareous sponges and corals, which belong to different species (Tab. 1 and 2). Some smaller Cordevolian patch reefs may have been formed within deeper-water sediments. An interesting facies sequence is developed in the Norian Dachstein Limestone reef of Pokljuka (Julian Alps), starting with deeper-marine cherty limestones, which gradually succeeded by crinoidal limestones followed by reef limestones and lagoonal Dachstein Limestones.     

Les formations du jurassique supérieur du Bou Rheddou au Nord de Tiaret (Bordure sud-Tellienne,Algérie): âge et milieux de dépôt

In the Bou Rheddou mountain (Southern Tellian border), new biostratigraphic data based on Ammonites, allow precise and modify the age of the Arkell & Busson formations. The Oxfordian «Ammonitico rosso facies begin in the Transversarium zone and go into the Planula zone. This zone is characterized for the first time in this region. Lower Tithonian (Hybonotum zone) and Upper Tithonian (Microcanthum zone) are also recognized. Precisions on depositional environment and paleogeography are given. Facies and low sedimentation show a pelagic shoal (abundant planctonic organisms) slightly subsiding and lately recovered by the Jurassic transgression. During Oxfordian, episodic interruption of the «Ammonitico rosso deposits shows an unstable period with terrigenous deposits (intra-oxfordian tectonic movements). The facies of the Northern-Gondwanian carbonated platform begin earlier in the Bou Rheddou zone (Oxfordian-Kimmeridgian boundary) than in the Southern regions, where the same facies appears only in Upper Kimmeridgian.     

High evolutionary rates and the origin of the Rosso Ammonitico Veronese Formation (Middle-Upper Jurassic of Italy) reptiles

The fossil record of metriorhynchids and plesiosaurians from the Rosso Ammonitico Veronese Formation (RAVFm, Middle–Upper Jurassic, Italy) is represented by elements collected between the eighteenth and twentieth centuries. All the metriorhynchid material is referred to the genus Neptunidraco. The first RAVFm plesiosaurian material was collected in the nineteenth century and referred to Plesiosaurus: elements are here described and interpreted as a chimerical association of crocodylomorph and plesiosaurian bones, providing the first co-occurrence of these clades in the RAVFm. The second plesiosaurian is the associated skeleton that we refer to Anguanax zignoi gen. et sp. nov. Bayesian phylogenetic analysis confirms the basal geosaurine affinities of Neptunidraco resulted by parsimony analysis. Using both methods, Anguanax was recovered as a basal pliosaurid, sister group of the clade including Marmornectes and Thalassophonea. Bayesian inference methods indicate that both Italian lineages diverged from other known lineages between 176 and 171 Mya, also showing divergence rates significantly higher than any other representative of their respective clades. We suggest a phase of rapid evolutionary adaptation to deeper marine environments in the ancestors of the Rosso Ammonitico Veronese reptiles as a response to the latest Liassic regressive regime in Northern Tethys.     

Stratigraphic framework, discontinuity surfaces, and regional significance of Campanian slope to ramp carbonates from central Dalmatia, Croatia

The sedimentology, microfacies, and stratigraphic age (from planktonic and benthic foraminifera and strontium-isotope stratigraphy) of a 300-m-thick Upper Cretaceous carbonate succession from the Island of ?iovo (central Dalmatia, Croatia) were analyzed in order to determine the lithostratigraphic, depositional, and chronostratigraphic framework. The Cretaceous strata were deposited in the southern part of the long-lasting (Late Triassic to Paleogene) Adriatic-Dinaridic Carbonate Platform (ADCP), one of a few late Mesozoic, intra-Tethyan, peri-Adriatic (sub)tropical archipelagos. The succession is separated by a firmground formational boundary into two lithostratigraphic units: the underlying Middle to Upper Campanian Dol Formation consisting of slope pelagic limestone with intercalated turbidites and debrites, and the overlying Upper Campanian ?iovo Formation composed of outer-ramp bioclastic-lithoclastic and echinoderm-dominated packstone. Age, lithology, and depositional settings of the ?iovo Formation are different from other penecontemporaneous, regionally important inner-platform carbonate successions within the ADCP domain. Therefore, the ?iovo Formation is proposed here as a new lithostratigraphic unit. Regionally important condensed intervals in the form of at least two firmground surfaces, characterized by Thalassinoides burrows (with phosphatic mineralization) that belong to the Glossifungites ichnofacies, occur in the lowermost part of the ?iovo Formation. Abrupt shallowing of depositional environments at the boundary between the Dol and the ?iovo Formation, and the generation of the formational boundary firmground, likely correlate with the regionally recorded Upper Campanian Event that represents a global eustatic sea-level fall. A regionally important subaerial exposure surface with nodular calcrete, rhizoliths, and Microcodium aggregates in the upper part of the ?iovo Formation represents a regional subaerial unconformity that was recorded across the ADCP domain and was interpreted as a consequence of diachronous and differential uplift of various parts of the platform in response to the formation of a forebulge in front of the approaching Dinaridic orogen.     

<Emphasis Type="Italic">Bevocastria magna</Emphasis> n. sp., eine neue Cyanobakterie aus den obertriassischen Riffkalken des Taurus-Gebirges (Türkei)

Bevocastria magna n. sp., an extremely large nodular species of the genusBevocastria, is described from Upper Triassic (Norian) reef limestones of a locality south of the town of Dereköy (SW Antalya, Turkey). The nodule ofB. magna looks like skeletons of chaetetid sponges which occur commonly at the same locality.B. magna is the first report of the genus from the Triassic deposits of Turkey.     

Millions of reptile tracks—Early to Middle Triassic carbonate tidal flat migration bridges of Central Europe—reptile immigration into the Germanic Basin

Discoveries of vertebrate track sites in Central Europe have occurred in 75 localities in carbonate tidal flats of the Middle Triassic. In the Germanic Basin carbonate tidal flats were wide-span mapped, resulting in the finding of millions of small- to medium-sized reptile tracks. In the west of the basin the sediment of the Lower Muschelkalk to basal Upper Muschelkalk contains at least 21 track horizons, whereas in the eastern part more typically marine conditions were present. Here, tidal flats with additional track beds started earlier during the Upper Bunter and demonstrated marine ingression from the eastern Silesian gate. During low stands these tidal flats comprised inter-peninsula bridges, which allowed migration of reptiles. Only two medium to small prolacertilian reptiles, which were fully adapted to these environments, left any kind of track. A large thecodont reptile such as Euparkeria was the potential predator that may rarely have hunted the main small trackmakers Macrocnemus and Hescherleria.