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The Middle Devonian Epoch, ~ 393–383 million years ago, is known for a peak in diversity and highest latitudinal distribution of coral and stromatoporoid reefs. About 388 million years ago, during the late Eifelian and earliest Givetian, climax conditions were interrupted by the polyphased Kačák Episode, a short-lived period of marine dys-/anoxia associated with climate warming that lasted less than 500 kyr. Reconstruction of the seawater temperature contributes to a better understanding of the climate conditions marine biota were exposed to during the event interval. To date, conodont apatite-based paleotemperatures across the Eifelian–Givetian boundary interval have been published from Belarus, France, Germany and North America (10–36° S paleolatitude). Here we provide new δ18Oapatite data from the Carnic Alps (Austria, Italy) and the Prague Synform (Czech Republic). For better approximation of the paleotemperature record across the Kačák Episode, a latitude-dependent correction for Middle Devonian seawater δ18O is applied. Because δ18Oapatite data from shallow marine sections are influenced by regional salinity variations, calculated mean sea surface temperatures (SST) are restricted to more open marine settings (22–34° S paleolatitude). Water temperatures reach ~ 34 °C in the Prague Synform and ~ 33 °C in the Carnic Alps and suggest that SSTs of the southern hemisphere low latitudes were ~ 6 °C higher than previously assumed for this time interval.

The polyphased Kacak Episode near the Eifelian-Givetian boundary (Middle Devonian), well documented globally, resembles other global biotic extinction events driven by climate change. High-resolution conodont biodiversity patterns from shallow marine, slope and pelagic bathymetric settings within the same basin from the Carnic Alps show that while conodonts experienced diversification during the latest Eifelian ensensis Biozone, assemblages suffered extinction during the early Givetian hemiansatus Biozone. Although a similar general pattern is observed in different bathymetric settings there is a changed taxonomic composition of conodont assemblages across the stage boundary. Based on microfacies analysis this change is contemporaneous with changes in palaeoenvironmental conditions in the earliest Givetian.

In the Carnic Alps, located across the border between Italy and Austria, several sections span the Silurian/Devonian boundary in different sedimentary settings, from very shallow water to moderately deep shelf. All studied sections yielded conodonts and based on the first and last occurrences of the conodont taxa in the upper part of the Upper Oul. el. detortus Zone and in the lower part of the I. hesperius Zone a detailed conodont biostratigraphic framework was able to be constructed for this interval. Comparison of data from different depositional settings demonstrates that, although the majority of species are documented everywhere in the Carnic basin, a few taxa, mainly represented by coniforms, are limited to shallow water, whereas others, mainly ozarkodinids, occur only in open sea deposits.

The Late Devonian (383-359 Ma) was a time of prolonged climate instability with catastrophic perturbation of global marine ecosystems at the Frasnian-Famennian (F-F) and the Devonian-Carboniferous (D-C) boundaries. The causes and mechanisms of anoxia and extinction at the F-F interval are not clearly delineated, and alternative explanations for virtually every aspect of this interval are still intensely debated. In many (but not all) locations, the F-F interval is characterized by two dark, organic-rich lithologies: the Lower and Upper Kellwasser beds (as originally described in Germany) that represent a stepwise ocean anoxia and extinction sequence. The Upper and Lower Kellwasser anoxia event beds are often collectively termed the Kellwasser Event, and the termination of this sequence is within the Upper Kellwasser Event at the F-F boundary. Current knowledge is limited by significant sampling bias, as most previous studies sampled epicontinental seaways or passive continental shelves, primarily from localities across Europe and North America. Together these formed a single equatorial continent with a rising mountain chain during the Late Devonian. Our understanding of the Kellwasser Event is thus based on data and observations from a restricted set of paleoenvironments that may not represent the complete range of Late Devonian environments and oceanic conditions. In the last decade, new methodologies and research in additional paleoenvironments around the world confirm that the Kellwasser Event was global in scope, but also that its expression varies with both paleoenvironment and paleogeography. Studying the many differing geochemical and lithological expressions of the Kellwasser Event using a) a wide variety of paleoenvironments, b) a multiproxy approach, and c) placement of results into the broader context of Late Devonian marine biodiversity patterns is vital for understanding the true scope of ocean anoxia, and determining the causes of the marine biodiversity crisis at the F-F boundary. Highlights • Bias in existing samples limits understanding of the Frasnian-Famennian biodiversity crisis and the Kellwasser anoxia event. • The Kellwasser Event was global but its expression is highly dependent on paleoenvironment and paleogeography. • The Kellwasser Event was due to "top-down" climate forcing with surface eutrophication not upwelling anoxic bottom water. • The F-F crisis was a lack of species origination in environments with climate stress and changes in sediment/nutrient supply.

The Lower Cretaceous marine deposits of the Himachal Himalaya are assigned to the Giumal Formation and best exposed in Spiti Valley (Northern India). To date, three sections near the villages of Chikkim, Domal and Gete are studied concerning its general lithological character and age. However, only the biostratigraphically constrained section near Chikkim exposes a complete succession of approximately 300 m in thickness with both lithostratigraphic boundaries preserved. Thus, it is representative for the entire Spiti area. Although some few lithological details on the siliciclastic sequence of the Giumal Formation are known, a comprehensive study of the regional sedimentary development is missing. A detailed microfacies study is performed for the entire sequence of Lower Cretaceous outer neritic to slope environments of Spiti. The specific sedimentary character of the unit results in discrimination of eleven microfacies types. Furthermore, twenty-three sedimentary sequences are identified which correspond with four major regressive/transgressive cycles. Reconstruction of a relative sea-level curve clearly indicates 10 major and minor sea-level drops which correlate well with eustatically induced megacycles between the latest Tithonian to the late Albian. The depositional environment of the Giumal Formation in Spiti is discussed in view of 16 coeval sedimentary sequences framing the Indian Craton during the Late Jurassic and Cretaceous time slice.

Sedimentary petrology and trace element geochemistry indicate that the Late Devonian to Early Carboniferous Heishantou Formation near Boulongour Reservoir (NW Xinjiang, China) was deposited on a steep slope, mid-latitude accreting island arc complex in an open oceanic system. Bulk 87Sr/86Sr ratios show excursion patterns that are consistent with excursions at the Devonian–Carboniferous (D–C) boundary in epicontinental margin sediments. Sedimentation rates for the Boulongour Reservoir sediments show highly variable rates that range from 0.5 cm/ky to 10 cm/ky, consistent with other Late Devonian sections and modern arc environments. Multiple whole rock geochemical proxies for anoxia and the size and distribution of pyrite framboids suggest the presence of the Hangenberg Event in the sediments associated with the D–C boundary, despite the lack of visible black shale. The presence of anoxia in an open ocean, island arc environment cannot be explained by upwelling of anoxic bottom waters at this paleolatitude, but can be explained by the global in?iction of oceanic shallow water eutrophication on to a climate system in distress.

Upper Devonian marine deposits of the Baruunhuurai Terrane in western Mongolia represent island arc settings, which yielded a diverse conodont assemblage of 30 taxa, including species of Ancyrognathus (as well as one new species), Icriodus, Mehlina, Polygnathus and Palmatolepis. Biodiversity analysis of Ancyrognathus, Pelekysgnathus, Mehlina and Icriodus shows that the Mongolian conodont assemblage consists of two endemic and few cosmopolitan taxa. Representatives of the otherwise globally distributed genus Pelekysgnathus are absent. An important factor influencing the regional distribution of conodont taxa seems to be the siliciclastic-dominated sedimentation of the Baruunhuurai Terrane during the early Famennian.

A rich assemblage of Middle Devonian (late Eifelian) polychaete jaws (scolecodonts) from the Blankenheimerdorf section in the type Eifel area, western Germany, is described. The top part of the section also reflects the onset of the global Kacak Event. The sediments of the section were deposited in a shallow to deep subtidal environment on the southern Avalonian margin. The habitat was obviously favourable for jaw-bearing polychaetes, which are represented by 18 species belonging to 9 genera. The assemblage is dominated by polychaetaspids, followed by mochtyellids, paulinitids and kielanoprionids. Notably, this study documents one of the oldest records of kielanoprionids, a polychaete family common since the Middle Devonian and closely related to the extant Hartmaniellidae. This may indicate that a prominent change in jawed polychaete evolution occurred during the Early–Middle Devonian transition. Moreover, we present new information on polychaete palaeobiogeography, which when compared with previously described Devonian scolecodonts shows that very similar polychaete faunas with many species in common were widespread in today's Europe and North America.

The Frasnian–Famennian mass extinction event devastated tropical marine ecosystems and ranks in the top six in taxonomic and ecological severity. The close stratigraphic association between the extinction and the Kellwasser Anoxia Events support a link between oceanographic anoxia and extinction. The Upper and Lower Kellwasser horizons have been identified in epicontinental and basinal settings in Laurussia, Gondwana, Siberia, and South China. The Hongguleleng Formation (Late Devonian) in northwestern Xinjiang, China, contains both the Frasnian–Famennian boundary and the rebound from the Frasnian–Famennian extinction event in a highly fossiliferous shallow marine setting associated with a Devonian oceanic island arc complex (part of the Central Asian Orogenic Belt, or CAOB). Here we show that the Hongguleleng Formation also records the Upper Kellwasser Anoxia Event through analysis of multiple geochemical proxies. In contrast to previous studies asserting that the Kellwasser Events were restricted to epicontinental seaways and basins, our results indicate that it occurred not only along the shallow continental margins of the closing Rheic Ocean, but also in shallow water in the open oceanic part of Paleotethys. Previous explanations for the Kellwasser Events from epicontinental margins and basins call for the migration of deep anoxic bottom water into shallow water environments as a kill mechanism for shallow marine ecosystems or attribute it to sea level rise and subsequent stagnation. There is no evidence that the Devonian oceans completely overturned during the Kellwasser Events; similarly, many transgressive events in the Devonian are not associated with black shales. We therefore suggest an alternative mechanism for the Kellwasser Events based on new evidence from the CAOB, where anoxia is driven by episodic eutrophication of surface waters.

Late Devonian to Early Carboniferous stratigraphic units within the ‘Zhulumute’ Formation, HonggulelengFormation (stratotype), ‘Hebukehe’ Formation and the Heishantou Formation near the BoulongourReservoir in northwestern Xinjiang are fossil-rich. The Hongguleleng and ‘Hebukehe’ formations are biostratigraphicallywell constrained by microfossils from the latest Frasnian linguiformis to mid-Famenniantrachytera conodont biozones. The Hongguleleng Formation (96.8 m) is characterized by bioclastic argillaceouslimestones and marls (the dominant facies) intercalated with green spiculitic calcareous shales. Ityields abundant and highly diverse faunas of bryozoans, brachiopods and crinoids with subordinatesolitary rugose corals, ostracods, trilobites, conodonts and other fish teeth. The succeeding ‘Hebukehe’Formation (95.7 m) consists of siltstones, mudstones, arenites and intervals of bioclastic limestone (e.g.‘Blastoid Hill’) and cherts with radiolarians. A diverse ichnofauna, phacopid trilobites, echinoderms(crinoids and blastoids) together with brachiopods, ostracods, bryozoans and rare cephalopods have beencollected from this interval. Analysis of geochemical data, microfacies and especially the distribution ofmarine organisms, which are not described in detail here, but used for facies analysis, indicate a deepeningof the depositional environment at the Boulongour Reservoir section. Results presented here concernmainly the sedimentological and stratigraphical context of the investigated section. Additionally, oneLate Devonian palaeo-oceanic and biotic event, the Upper Kellwasser Event is recognized near the sectionbase.

IGCP 596 (2011-2015) has a primary focus on climate change and biodiversity patterns in the Mid-Paleozoic (Early Devonian to Late Carboniferous). As a part of this project, we conducted a field workshop in western Mongolia in the summer of 2012. The goal was to locate fossiliferous sections that expose the stage boundaries from the Eifelian/Givetian boundary (Middle Devonian) to the Devonian/Carboniferous boundary to expand our knowledge of the key Devonian biotic and geochemical events such as the Frasnian/Famennian extinction event and the Kacak, Kellwasser and Hangenberg oceanographic events. During the field workshop, we examined sections in the Nariinhar Formation, Baruunhuurai Formation and Samnuuruul Formation from the Baruunhuurai Terrane.

Knowledge of the Early Cretaceous ammonoids of the NW-Himalayas was poor until recent discoveries. Intense sampling from the Giumal Formation exposed near the village of Chikkim (Spiti Valley, Himachal Pradesh, India) led to the recognition of a new Early Cretaceous ammonoid fauna. The succession consists of arenitic sandstone interbedded with shale that was deposited by turbidity currents on an unstable shelf in the Early Cretaceous. Ammonoids have been obtained only from sandstone beds in the lower one-third and close to the top of the c. 350-m-thick section. Eight new ammonoid taxa (1 genus and 7 species) are described: Sinzovia franki sp. nov. (rare), Giumaliceras giumaliense gen. et sp. nov. (abundant), Giumaliceras bhargavai gen. et sp. nov. (rare), Neocomites (Eristavites) platycostatiformis sp. nov. (rare), Cleoniceras oberhauseri sp. nov. (abundant), Australiceras himalayense sp. nov. (rare) and Deshayesites fuchsi sp. nov. (rare). Sinzovia and Deshayesites are reported for the first time from the Tethyan Himalaya. According to the biostratigraphic relevance of some ammonoid taxa described here, the age of the Giumal Formation can be constrained from Berriasian (Giumaliceras assemblage) to Aptian (Cleoniceras assemblage). The discovery of the new fauna substantiates the significance of the Giumal Formation around Chikkim and facilitates comparison with faunal assemblages from other regions in the Tethys Ocean and beyond.

The new Project 596 (2011-2015) within the International Geoscience Programme (IGCP) started in April 2011. It focuses on climate change and biodiversity patterns in the Mid-Paleozoic (Early Devonian to Late Carboniferous). Here we provide a summary of activities during the Opening Meeting. The first annual conference resulted in a consolidation of a global network including researchers of other large projects such as IGCP 580 and IGCP 591. Until now the group of participants interested in collaboration counts 135 scientists of 26 countries of which more than one-third are women in science. Participants come form Australia (2), Austria (3), Belgium (10), Bulgaria (2), Canada (1), China (1), Czech Republic (12), Estonia (1), France (13), Germany (11), Iran (1), Italy (5), Japan (7), Malaysia (1), Mongolia (4), Morocco (1), Myanmar (1), Poland (8), Portugal (2), Russia (10), Spain (19), Thailand (4), Turkey (3), United Kingdom (3), U.S.A. (9), and Vietnam (1). In order to secure the future of the international collaboration within IGCP 596, further financial support is acquired by project-grants from national science institutions of several countries. In addition to the achievements during the Opening Meeting, a short overview on other joint conferences held in 2011 and those scheduled for 2012 is given.

The Basal Chotec or jugleri Event, close above the Lower–Middle Devonian boundary, has been regarded as a minor but important eustatic transgressive event, which is characterized by significant environmental changes, faunal extinction, appearance of new forms, and maximum radiation, particularly among the goniatites. This study contributes to a more precise stratigraphic allocation of the event, and provides a reconstruction of paleoenvironmental settings in the type area of the event, the Prague Basin (Czech Republic). The beginning of a transgression is recorded already in the Třebotov Limestone (partitus Zone, Eifelian, early Middle Devonian). The basin-wide change in the sedimentation pattern (onset of peloidal and crinoidal grainstones (calciturbidites) of the Chotec Formation) corresponding to the uppermost partitus and costatus conodont zones, base of Nowakia (Dmitriella) sulcatasulcata dacryoconarid Zone, and Pinacitesjugleri goniatite Zone is interpreted here to be linked to a maximum flooding of the basin. A hypothesis of enhanced nutrient load during sedimentation of the Chotec Formation is suggested here as a triggering mechanism for intense micritization and peloid formation and prasinophyte blooms, which could be, along with a greater depositional depth, responsible for oxygen deficiency and consequent reduction of diversity and habitat tracking among benthic invertebrates.

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.

Twenty-nine species of bryozoans from the Upper Ordovician–Lower Silurian Pin Formation (Spiti, India) have been identified. Eight of these are new: Trematopora minima, Ulrichostylus bhargavai, Ptilodictya exiliformis, Phaenopora ordinarius, Oanduellina himalayaica, Pesnastylus? vesiculosum, Ralfina? originalis and Pinocladia triangulata. The fossil record and facies analyses of the area investigated indicate shallow-water conditions within the subtropical–tropical realm. The distribution pattern of fossils among the Ordovician/Silurian succession on the Northern Gondwana shelf and the influence of the Late Ordovician cooling phases on marine organisms are distinctive owing to a dramatic reduction in diversity globally. As far as the bryozoan taxa of Spiti are concerned, only one (Helopora fragilis) of the 29 species was recorded above the Ordovician/Silurian boundary. Observed bryozoan communities are very similar to faunas of Laurentia, the Baltic, Siberia and southern China of early–late Ordovician age.

Palaeozoic sediments of Austria are separated by the Periadriatic Fault into Eastern Alpine (Upper, Middle and Lower Austroalpine) and Southern Alpine units. We herein present six case studies showing up the different development of shallow-marine communities with special regard to carbonate factories and shell pavements occurring in both regions during the Siluro-Devonian time span. Upper Silurian–Upper Devonian deposits of the Eastern Alps comprise accumulations of serpulid tubes (Southern Burgenland) and Septatrypa pavements, Amphipora mounds, coral-stromatoporoid–biostromes and Stachyodes–auloporoid beds regarded as pioneer reef communities (Graz Palaeozoic), respectively. Lower Silurian strata of the Southern Alps consist of pelagic sediments persisting to the Upper Silurian and therefore differ from contemporaneous successions in the Eastern Alps. Intercalated in Ludlow orthocerid limestone beds Cardiola pavements appear (Carnic Alps). Within the Lower Devonian sequence, mounds were built by baffling calcareous algae and tabulozoan communities. Coral–stromatoporoid patch reefs occur during the Pragian, Givetian and Frasnian stages. Investigation of Silurian–Upper Devonian reefs and reef-related successions within Austria’s borders has a long tradition. A survey of these developments is compiled in a stratigraphic scheme representing all non-metamorphic units of Austria. Generally all Palaeozoic strata suffered differing post-depositional destruction, i.e. tectonic splitting, dolomitization, metamorphic overprint, etc., during Variscan and Alpidic orogenesis thus complicating or limiting to some respect their investigation. From Southern Burgenland, the Graz Palaeozoic, the Carnic Alps and the Karawanken Mountains ‘reefs’, which cover a time-segment of some 55 Ma, are presented in overview. Stratigraphical framework of dismembered

A new subproject of IGCP 596 (Climate change and biodiversity patterns in the Mid-Paleozoic) started in 2015. The Goal of the project is to increase the record of rugose coral biodiversity and to provide a high-resolution biostratigraphy especially of Devonian fossil-rich deposits in western Mongolia. A big step was achieved with the Conodont Workshop held in Graz, Austria (25.09-01.10.2015) exclusively for teaching conodont extraction techniques to colleagues from the Paleontological Center of the Mongolian Academy of Sciences (MAS) and the School of Geology and Petroleum Engineering of the Mongolian University of Science and Technology (MUST). With the knowledge provided during the workshop, in both microfossil laboratories at the MAS and at the MUST units for conodont extraction were established.

The development and behavior of million year- scaled depositional sequences recorded within Palaeozoic carbonate platform has remained poorly examined. There- fore, the understanding of palaeoenvironmental changes that occur in geological past is still limited. We herein undertake a multi-disciplinary approach (sedimentology, conodont biostratigraphy, magnetic susceptibility (MS), and geochemistry) of a long-term succession in the Carnic Alps, which offers new insights into the peculiar evolution of one of the best example of Palaeozoic carbonate platform in Europe. The Freikofel section, located in the central part of the Carnic Alps, represents an outstanding succession in a fore-reef setting, extending from the Latest Givetian (in- det.falsiovalis conodont zones) to the Early Famennian (Lower crepida conodont zone). Sedimentological analysis allowed to propose a sedimentary model dominated by distal slope and fore-reef-slope deposits. The most distal setting is characterized by an autochthonous pelagic sedi- mentation showing local occurrence of thin-bedded turbi- ditic deposits. In the fore-reef slope, in a more proximal setting, there is an accumulation of various autochthonous and allochthonous fine- to coarse-grained sediments origi- nated from the interplay of gravity-flow currents derived from the shallow-water and deepwater area. The temporal evolution of microfacies in the Freikofel section evolves in two main steps corresponding to the Freikofel (Unit 1) and the Pal (Unit 2) limestones. Distal slope to fore-reef lithologies and associate changes are from base to top of the section: (U1) thick bedded litho- and bioclastic breccia beds with local fining upward sequence and fine-grained mud- stone intercalations corresponding, in the fore-reef setting, to the dismantlement of the Eifelian-Frasnian carbonate platform during the Early to Late Frasnian time (falsiovalis to rhenana superzones) with one of the causes being the Late Givetian major rift pulse; (U2) occurrence of thin- bedded red nodular and cephalopod-bearing limestones with local lithoclastic grainstone intercalations corre- sponding to a significant deepening of the area and the progressive withdrawal of sedimentary influxes toward the basin, in relation with Late Frasnian sea-level rise. MS and geochemical analyses were also performed along the Fre- ikofel section and demonstrate the inherent parallel link existing between variation in MS values and proxy for terrestrial input. Interpretation of MS in terms of palaeo- environmental processes reflects that even though distality remains the major parameter influencing MS values, car- bonate production and water agitation also play an impor- tant role.

The Carnic Alps represent the best exposed Paleozoic succession within the Alpine domain being fossiliferous, mostly non-metamorphic and largely complete. This study focuses on the area around Mt. Pizzul, because the bedrocks record well the basin dynamics and most of the units are conodont bearing. Our aims were to contribute to the procedure of formalization of the lithostratigraphic units and to understand the depositional and deformation history of the study area. The area has been mapped, tectonic overprint constrained and the successions described, measured and dated. As a second-order aim, we discuss these data to infer the relations with other parts of the Carnic basin and to recognize the global controls on sedimentation. The depositional evolution can be sketched as follows: pre-Hirnantian ramp-type margin; Hirnantian glacioeustatic-related deposits and unconformity; pelagic deposition in a ramp-type margin (Přidoli–Eifelian); slope formation and differentiation in buildup, foreslope and pelagic environments (Eifelian–Frasnian); transgression and reef drowning (Frasnian–Visean); probable subaerial exposures likely during in uppermost Famennian and Visean times; and turbidite deposition (Visean). Global controls or deposits suggesting a global control are documented, including the Boda Event, the Hirnantian glaciation, the Middle Devonian reef growth, the Kacak Event, and the high-frequency sea-level fluctuations around the Devonian–Carboniferous boundary. The drowning of the buildups here and elsewhere in the Carnic Alps started during the Frasnian, unlike observed globally. This suggests that local tectonics lead to progressive deepening up to the transition to turbidite deposition.

A new conodont species, Icriodus marieae, is described from pelagic limestone beds of the Carnic Alps (Austria). Specimens are obtained from the upper part of the Valentin Formation (Central Carnic Alps) and range from the latest Eifelian to middle Givetian. Significantly differing from other icriodontid conodonts is that the icriodontan element of the new species develops only three denticles on either lateral denticle row, which are constricted to the central part of the element. The anterior part of the element is free of lateral row denticles and consists of two to four denticles, which have a fan-shaped outline in lateral view. The anterior part as well as the posterior part (consisting of cusp and two to three pre-cusp denticles) is higher than the denticles of the central part of the element. Shape analysis confirms that the parameters chosen for landmarks (element size relation and denticle setting) show little variation between different specimens.