A new peirosaurid (Crocodilyformes) from the Late Cretaceous (Turonian–Coniacian) of Patagonia,Argentina

Peirosauridae is composed of mid- to large-sized terrestrial mesoeucrododylian crocodyliforms distributed throughout Gondwanan landmasses. Here we describe a new peirosaurid that comes from the upper levels of the Portezuelo Formation (Turonian–Coniacian, Upper Cretaceous) from Loma de la Lata, Neuquén Province, Argentina. This specimen consists of some associated bones belonging to a single individual. In order to facilitate comparisons, we recognise two different peirosaurid morphotypes based on skull shape: broad- and narrow-snouted taxa. The new taxon may be related to broad-snouted taxa, especially Gasparinisuchus peirosauroides. The new taxon here reported has strong heterodont dentition when compared with other peirosaurids. As in related forms, the fourth dentary tooth is caniniform, very large, acute and transversely compressed (much more than other peirosaurids), and the anterior dentary teeth have less globular, sharp serrated crowns. Large interalveolar spaces are present between both mandibular and maxillary teeth, a trait only observed on the new taxon. With this addition, we elevate the number of Patagonian peirosaurids to four. Moreover, it represents together with Lomasuchus palpebrosus the second peirosaurid species described for the Portezuelo Formation.     

A new Semionotid (Actinopterygii,Neopterygii) from the Late Jurassic–Early Cretaceous of Thailand

A new semionotid fish, Lepidotes buddhabutrensis n. sp., is described from the continental Late Jurassic–Early Cretaceous Phu Kradung Formation, Phu Nam Jun, Kalasin Province. L. buddhabutrensis is characterized notably by the pattern of its cheek bones, by its short preorbital region, and by its numerous and well-developed premaxillary teeth. L. buddhabutrensis is provisionally placed in the genus Lepidotes; it shares, however, derived characters with other semionotids, such as Araripelepidotes and Pliodetes. To cite this article: L. Cavin et al., C. R. Palevol 2 (2003).     

Late Viséan (MFZ14) foraminifers and algae from the Kirchbach Limestone (Carnic Alps,Austria) and geological implications

The Kirchbach Limestone occurs in the middle part of the early Viséan to Bashkirian Hochwipfel Formation, which was deposited in a flysch basin that formed during an extensional rifting phase in the foreland of the Noric Terrane, was filled with deep-marine synorogenic sediments and closed during the Bashkirian. The Noric Terrane split off from Gondwana and drifted towards the north, closing the flysch basin, which was part of the Paleo-Tethys. The Kirchbach Limestone is composed of bioclastic mudstone and carbonate conglomerate. Microfacies of the limestone clasts include wackestone, packstone, grainstone, and rudstone with diverse fossil assemblages. Bindstone clasts are derived from very shallow, restricted environments. Other clasts are bioclastic mudstone derived from deeper settings. All the foraminifers and algae identified correspond to the upper MFZ14 biozone, after the appearance of Bradyina; in contrast, the markers of the uppermost MFZ14 (Asteroarchaediscus, Loeblichia paraammonoides, and Warnantella) and those of MFZ15 (Janischewskina, Climacammina, and Biseriella) are totally absent. The Kirchbach markers are Cribrospira mikhailovi, Bradyina cf. flosculus, Howchinia bradyana, and Eostaffella parastruvei. Revised local taxa are Mstinia, M. minima n. comb., Consobrinellopsis n. gen., and C. ex gr. consobrina n. comb. The Kirchbach Limestone is derived from a shelf area displaying various shallow-water environments from which the clasts were transported into deeper-marine environments as sediment gravity flows. Limestone clasts of the Kirchbach Limestone indicate the presence of a shallow carbonate shelf along the northern margin of the Hochwipfel flysch basin. The late Asbian (MFZ14) limestone clasts derived from this carbonate shelf were probably subaerially exposed prior to their reworking and redeposition within the flysch sediments, which are late Brigantian (MFZ15) in age. Fossiliferous carbonate shelf sediments of Viséan–Serpukhovian (Namurian) age in the Veitsch Nappe of the eastern Graywacke Zone may be remnants of this shelf. Similar trilobite faunas of Nötsch and Veitsch indicate that they were originally adjacent and probably connected to this shelf north of the flysch basin. These data confirm that the Carnic Alps were located in the Viséan Mediterranean subprovince.     

The Late Triassic speciesCryptaulax? bittneri (Mollusca: Gastropoda: Procerithiidae) and remarks on early aspects of the Mesozoic marine revolution

Cryptaulax? bittneri, also known asPromathildia bittneri, is frequently reported to be present in Late Triassic biotas and is cited as a species with almost cosmopolitan distribution (S-Alps, S-America, Iran, Karakorum). Re-examination of the holotype of the species shows that nearly all reports are based on misidentifications. This species is known only from the holotype and thus it is known only from its type locality, the Cassian Formation (S-Alps, Italy). Frequent misidentifications show thatCryptaulax bittneri is poorly known and therefore the holotype is figured and redescribed. It is one of the earliest cerithioid gastropods that has a complex teleoconch ornament typical of many modern Cerithioidea. This complex ornament of axial ribs and spiral cords with knobby intersections could represent an early aspect of the Mesozoic marine revolution. A complex teleoconch ornament and a carinated larval shell could represent apomorphies of the Mesozoic Procerithiidae, since these characters are absent in the known Palaeozoic Cerithimorpha. The Recent genusArgyropeza is so similar to the procerithiid genusCryptaulax thatArgyropeza can be considered to represent a living fossil.Xystrella inaequelineata Nützel &; Senowbari-Daryan 1999 from the Late Triassic Nayband Formation of central Iran is transferred toCryptaulax.     

Plants of Leptostrobus Heer （Czekanowskiales） from the Early Cretaceous and Late Triassic of China, with Discussion of the Genus

Investigation of the Mesozoic seed plant Leptostrobus Heer from the Yangcaogou Formation of the Late Triassic and the Yixian Formation of the Early Cretaceous, Liaoning Province, China, provides new Insight Into Its general morphology and geographical distribution. The materials of L. cancer from the Yixian Formation described herein are later than all the past findings of this species and add to the record of L. cancer during the Early Cretaceous. Based on well-preserved specimens, the specific diagnosis Is slightly emended and the reconstructlon of L. cancer Is perfected. The materials from the Yangcaogou Formation of the Late Triassic are placed in L. spheericus, in addition, we review the history of investigation of the genus Leptostrobus since its establishment in 1876 and discuss the main characteristics of each species.     

Triassic/Jurassic carbonates from the Hochfelln Mountain (Northern Calcareous Alps)—its facies, silicified fauna and implications for the end-Triassic biotic crisis

A suite of Early Mesozoic (Late Triassic, Norian to Early Jurassic) calcareous beds was studied from the Hochfelln Mountain in the Northern Calcareous Alps (NCA, South Germany). The Hauptdolomit Group consists of thick peritidal deposits and is overlain by basin deposits of the Rhaetian Kössen Formation and Rhaetian reefoidal limestone with corals. Unlike many other sections in the Tethys realm, coral growth seems to continue into the Jurassic or starts again relatively early within the Early Jurassic. Silicified corals and other marine invertebrates are present in the calcareous, micritic Hochfelln Beds. A re-examination of previously collected ammonite material indicates the presence of Coroniceras sp. which suggests an Early Sinemurian age for the Hochfelln Beds. Abundant sponge spicules (spiculites) suggest that sponges were the source for the silicification. The site produced one of the most diverse Early Jurassic (Sinemurian) gastropod faunas of the NCA (25–30 species, some undescribed). The relatively diverse Early Sinemurian gastropod fauna and coral growth indicate rapid recovery from the end-Triassic biotic crisis.     

Paleoenvironmental and paleoclimatic changes during the Late Cretaceous and Cretaceous–Paleogene (K/Pg) boundary transition in Tattofte,External Rif,northwestern Morocco: implications from dinoflagellate cysts and palynofacies

This paper presents a quantitative study of dinoflagellate cysts (dinocysts) and palynofacies of the Campanian–Danian marly succession at the village of Tattofte (western External Rif, northwestern Morocco). The paleoenvironmental and paleoclimatic interpretations, inferred from this palynologic analysis, are compared to coeval sequences of other areas in the Northern Hemisphere. Changes in the relative abundances of dinocyst taxa, which are paleoenvironmental indicators, throughout the section suggest a deposition in a marine inner to outer neritic setting. The upper Campanian dinocyst assemblage is characterized by the presence of outer neritic-oceanic and low productivity indicator taxa (e.g., Spiniferites spp., Odontochitina spp.) and cold-water taxa (e.g., Manumiella spp., Chantangiella spp., Laciniadinium spp.), whereas, the lower Maastrichtian assemblage is characterized by inner neritic, high productivity and warm-water indicator taxa (e.g., Palaeocystodinium spp., Andalusiella spp.). The upper Maastrichtian dinocyst assemblage displays a return to an outer neritic environment under a transgressive regime, but with a cooling pulse and a moderate productivity. However, the Cretaceous–Paleogene (K/Pg) boundary interval records remarkable changes in the relative abundances of dinocyst taxa, indicating an inner neritic (coastal) setting, which is the most proximal in the study section; such changes reflect instable paleoenvironmental conditions which may be related to global cooling periods, likely caused by the Deccan volcanism in India and/or the Chicxulub asteroid impact in Mexico at the K/Pg boundary. In the Danian, the dinocyst relative abundances indicate a gradual return to stable environmental conditions.A quantitative analysis of the kerogen plots (palynomorphs, phytoclasts and amorphous organic matter (AOM)) reveals five types of palynofacies, generally indicating oxic to suboxic marine environments. The upper Campanian and upper Maastrichtian (lowermost part) strata are characterized by a playnofacies (V), indicating a distal shelf, while the lower Maastrichtian and lower Danian (uppermost part) strata record a playnofacies (III), reflecting an intermediate inner-outer neritic environment. However, the K/Pg boundary transition is characterized by playnofacies types (I) and (II), indicating a proximal (coastal) environment.     

Late Cretaceous (Cenomanian–Maastrichtian) calcareous nannofossils from Goban Spur (DSDP Sites 549, 551): Implications for the palaeoceanography of the proto North Atlantic

The early late Cretaceous (Cenomanian–early Turonian) is thought to have been one of the warmest periods of the Phanerozoic. This period was characterised by tropical sea surface temperatures of up to 36 °C and a pole-to-equator-gradient of less than 10 °C. The subsequent Turonian–Maastrichtian was characterised by a continuous climatic cooling, peaking in the Maastrichtian. This climatic cooling and the resulting palaeoceanographic changes had an impact on planktic primary producer communities including calcareous nannofossils. In order to gain a better understanding of these Cenomanian–Maastrichtian palaeoceanographic changes, calcareous nannofossils have been studied from the proto North Atlantic (Goban Spur, DSDP Sites 549, 551). In order to see potential differences between open oceanic and shelf dwelling nannofossils, the data from Goban Spur have been compared to findings from the European shelf (northern Germany).A total of 77 samples from Goban Spur were studied for calcareous nannofossils revealing abundant (mean 6.2 billion specimens/g sediment) and highly diverse (mean 63 species/sample) nannofossil assemblages. The dominant taxa are Watznaueria spp. (mean 30.7%), Prediscosphaera spp. (mean 18.3%), Zeugrhabdotus spp. (mean 8.3%), Retecapsa spp. (mean 7.2%) and Biscutum spp. (mean 6.6%). The Cenomanian assemblages of both Goban Spur (open ocean) and Wunstorf (shelf) are characterised by elevated abundances of high fertility taxa like Biscutum spp., Zeugrhabdotus spp. and Tranolithus orionatus. Early Turonian to Maastrichtian calcareous nannofossil assemblages of Goban Spur are, however, quite different to those described from European sections. Oceanic taxa like Watznaueria spp., Retecapsa spp. and Cribrosphearella ehrenbergii dominate in Goban Spur whereas the fertility indicators Biscutum spp. and T. orionatus are more abundant in the European shelf assemblages. This shift from a homogeneous distribution of calcareous nannofossils in the Cenomanian towards a heterogeneous one in the Turonian–Maastrichtian implies a change of the ocean circulation. The “eddy ocean” system of the Cenomanian was replaced by an oceanic circulation similar to the modern one in the Turonian–Maastrichtian, caused by the cooling. The increased pole-to-equator-gradients resulted in an oceanic circulation similar to the modern one.     

Late Norian (Triassic) Radiolaria from the Kotel’nyi Island (New Siberian Islands,Arctic, Russia)

Two radiolarian assemblages were recovered from upper Norian strata of the Kotel’nyi Island (Russia); the first assemblage, from the Monotis zabaikalica Subzone (lower part of Upper Norian), is represented by Betraccium inornatum Blome, Dumitricaella (?) parva Sugiyama, Ferresium titulense Blome and 24 other species; the second assemblage, from the Monotis subcircularis Subzone (upper part of Upper Norian), is represented by Crucella sp. cf. C. angulosa Carter, Kahlerosphaera acris Bragin, K. sp. cf. K. parvispinosa Kozur & Mostler, Pseudohagiastrum crassum (Carter) and 11 other species. Both assemblages have common taxa with Upper Norian and Rhaetian radiolarian assemblages of British Columbia and they display clear Boreal features: low taxonomic diversity, abundance of taxa known from high-latitude regions, absence or rare presence of taxa known from low-latitude areas. The presence of early representatives of nassellarian genera Droltus and Parahsuum is very distinctive. Six new species are described: Pseudohagiastrum spinosum nov. sp., Cantalum boreale nov. sp., Plafkerium carteri nov. sp., Droltus guttaeformis nov. sp., Laxtorum blomei nov. sp., L. glacialis nov. sp.     

Late Triassic and Lower Jurassic Foraminifera of the carbonate platform of the Beyaz Aladağ Group (Eastern Taurus,Turkey): New stratigraphic implications

Foraminifera have proven to be reliable biostratigraphic indicators. Accordingly, Triassic and Early Jurassic benthic Foraminifera allow us to define a biostratigraphic zonation within the carbonate platform of Kayseri (Yahyal?), Göksun (Kahramanmara?) and Sivas (Delikta?) regions in the Eastern Taurus (Ceviz, Alada?, Kaman and Felfan Mountains). Seven new stratigraphic sections are described in detail and the first precise inventory and illustration of the benthic foraminifer assemblages from the Triassic successions are presented over a large geographic area. The stratigraphic and palaeontological features of the Lower Mesozoic carbonate units of these mountains include several synchronous transgressive–regressive events that suggest continuity of the Lower Mesozoic environments over a large parautochthonous Taurus zone. Palaeogeographic considerations about the Eastern Taurus carbonates are given, evidencing three stages of development underwent by the studied area: 1) a stable continental margin from Lower Triassic to Lower Cretaceous; 2) a dismantling of the continental margin and first emplacement of ophiolites in the Upper Cretaceous; and 3) a deformation of the continental margin and emplacement of the Peridotite Nappe in the uppermost Cretaceous (Maastrichtian).     

Taxonomic study of the tetrahedral, pentagonal and hexagonal spongy spumellarian Radiolaria from the middle Carnian (Late Triassic) of the Köseyahya nappe (Elbistan, SE Turkey) and other Triassic localities

This article is a taxonomic study of all spongy radiolarian taxa with five to six coplanar and four tetrahedrally disposed spines or spongy arms occurring in the middle Carnian from the Köseyahya section, near the town of Elbistan, SE Turkey. This fauna is characteristic of the Tetraporobrachia haeckeli radiolarian Zone, and comes from an 8 m thick succession of clayey–cherty limestones occurring at the lower part of the section. In addition, a few species from the Middle and Upper Triassic from other areas have been also included in this study to improve some generic diagnoses and to better understand the diversity and evolutionary trends of some genera, subfamilies and families. The taxonomy at the generic and suprageneric levels is based primarily on the types of microsphere. This new approach allowed new taxonomic arrangements of genera and suprageneric units, and suggested new and unexpected phylogenetic relationships among these radiolarians and between them and younger radiolarians. The authors discuss and describe 42 species, of which 36 are new, and 12 genera of which three are new (Charlottalum, Pentaspongodisculus, and Trimiducaella). The genera Pseudohagiastrum Pessagno, Natraglia Pessagno, Cantalum Pessagno and others are reinterpreted. All the genera studied, except Charlottalum, are assigned to three subfamilies, of which two (Pseudohagiastrinae and Trimiducinae) are new, and to two families (Angulobracchiidae and Relindellidae). The genus Charlottalum is described to replace the genus Cantalum, which has been erroneously used until present for Late Triassic pantanelliids with four tetrahedrally disposed three-bladed spines.     

Species Richness and Evidence of Random Patterns in Assemblages of South American Titanosauria during the Late Cretaceous (Campanian–Maastrichtian)

The Titanosauria were much diversified during the Late Cretaceous, but paleobiological information concerning these sauropods continues to be scarce and no studies have been conducted utilizing modern methods of community analysis to infer possible structural patterns of extinct assemblages. The present study sought to estimate species richness and to investigate the existence of structures in assemblages of the South American Titanosauria during the Late Cretaceous. Estimates of species richness were made utilizing a nonparametric estimator and null models of species co-occurrences and overlapping body sizes were applied to determine the occurrence of structuring in this assemblages. The high estimate of species richness (n = 57) may have been influenced by ecological processes associated with extinction events of sauropod groups and with the structures of the habitats that provided abundant support to the maintenance of large numbers of species. The pseudocommunity analysis did not differ from that expected by chance, indicating the lack of structure in these assemblages. It is possible that these processes originated from phylogenetic inertia, associated with the occurrence of stabilized selection. Additionally, stochastic extinction events and historical factors may also have influenced the formation of the titanosaurian assemblages, in detriment to ecological factors during the Late Cretaceous. However, diagenetic and biostratinomic processes, influenced by the nature of the sedimentary paleoenvironment, could have rendered a random arrangement that would make assemblage structure undetectable.     

Taxonomic study of spongy spumellarian Radiolaria with three and four coplanar spines or arms from the middle Carnian (Late Triassic) of the Köseyahya nappe (Elbistan, SE Turkey) and other Triassic localities

The present article is a taxonomic study of all spongy spumellarian radiolarian taxa with three and four coplanar spines or spongy arms occurring in the middle Carnian from the Köseyahya section, near the town of Elbistan, SE Turkey. This fauna is characteristic of the Tetraporobrachia haeckeli radiolarian Zone, and comes from an 8 m thick succession of clayey-cherty limestones occurring at the lower part of the section. In addition, a few species from the Middle and Upper Triassic from other areas have been also included in this study to improve some generic diagnoses, and to better comprehend the diversity and evolutionary trends of some genera, subfamilies and families. The taxonomy at the generic and suprageneric levels is based primarily on the types of microsphere. This new approach allowed new taxonomic arrangements of genera and suprageneric units, and suggested new phylogenetic relationships among these radiolarians and between them and younger radiolarians. The authors discuss and describe 69 species, of which 37 are new, and 14 genera, of which three are new (Paraparonaella, Pseudangulobracchia, and Ropanaella). The genus Triassoastrum and others are reinterpreted. All genera studied are assigned to five subfamilies, of which two are new (Tetrapaurinellinae and Triassocrucellinae), and two families (Tritrabidae and Veghicycliidae). Nine species in open nomenclature are also illustrated.     

Cyrtocrinids (Cyrtocrinida,Crinoidea) and other associated crinoids from the Jurassic (Kimmeridgian–Tithonian)–Cretaceous (Berriasian–Barremian) of the Carpathian Foredeep basement (western Ukraine)

Upper Jurassic (Kimmeridgian–Tithonian) and Cretaceous (Berriasian–Barremian) strata of the Ukrainian part of the Carpathian Foredeep basement are rich, at least locally, in crinoid remains. Crinoids belonging to cyrtocrinids (Cyrtocrinida) are represented by whole cups, isolated remains of disarticulated cups, brachial plates and columnals. They are assigned to the following taxa: Cyrtocrinida indet., Eugeniacrinites cf. cariophilites (von Schlotheim), Lonchocrinus sp., Phyllocrinus stellaris Zaręczny, Ascidicrinus pentagonus (Jaekel), Gammarocrinites sp., Psalidocrinus armatus (Zittel), Psalidocrinus sp., and Hemibrachiocrinidae gen. indet. Cyrtocrinids are associated with other stalked (isocrinids, Isocrinida and millericrinids, Millericrinida) and stemless (saccocomids, Roveacrinida) crinoids. Columnals, pluricolumnals, brachial plates, and cirrals of isocrinids are assigned to Balanocrinus sp., Isocrinina fam. et subfam. indet., and columnals of millericrinids to Millericrinida indet. Free-living roveacrinids are assigned to Saccocoma sp. and Crassicoma sp. Knowledge on Jurassic and Cretaceous crinoids formerly described from Ukraine is discussed. Although majority of crinoids described herein seems to be allochthonous, autochthonous forms were also found with certainty in some intervals. These include some cyrtocrinids, which dominate in shallow-water environments of the Ukrainian Carpathian Foredeep basement. Isocrinids are also common in this shallow marine environment, whereas sessile saccocomids are assigned to low-energy, mud-supported bottom, open marine, outer-platform/upper slope, and relatively deep environments.     

Solution structure of Fe(II)–azide–bleomycin derived from NMR data: transition from Fe(II)–bleomycin to Fe(II)–azide–bleomycin as derived from NMR data and structural calculations

The coordination cage of the metal center in Fe(II)-bleomycin has been proposed to consist of the secondary amines in β-aminoalanine, the pyrimidinylpropionamide and imidazole rings, and the amide nitrogen in β-hydroxyhistidine as equatorial ligands, and the primary amine in β-aminoalanine and either the carbamoyl group in mannose or a solvent molecule occupying the axial sites. With the aim of supporting or not supporting coordination of a water molecule to the metal center in Fe(II)-bleomycin, the solution structure of Fe(II)-azide-bleomycin has been derived from NMR data. The structural changes that occur in Fe(II)-bleomycin upon azide binding have been monitored by comparing the experimental results with those obtained from the calculated structures for both bleomycin adducts. The results of this investigation strongly support a model of Fe(II)-bleomycin with six endogenous ligands as the most likely structure held in solution by this metallobleomycin in the absence of DNA.     

Proteromorphosis of Neospathodus (Conodonta) during the Permian–Triassic crisis and recovery

The Permian–Triassic evolution of platform conodonts (Gondolellidae) consists mainly of the development of the carina and the platform. During the sublethal environmental stress conditions subsequent to the Permian–Triassic extinction, the Wuchiapingian–Griesbachian Clarkina lineage is replaced by the primitive looking platform-lacking Dienerian–Aegean Neospathodus kummeli–Kashmirella timorensis lineage. It is assumed that, above Jinogondolella denticulata, end of the Capitanian Jinogondolella lineage, “Neospathodus” arcucristatus, an atavistic blade-like homeomorph that lacks a platform, underlies Protoclarkina crofti, of the base of the anagenetic Clarkina lineage. These primitive-looking forms are derived from their immediate ancestors by retrograde evolution, a phenomenon that has been described as proteromorphosis. Such events suggest that proteromorphosis occurs during periods of crisis, with the sudden reappearance of homeomorphic forms that are atavistic representatives of the clade. The phenomenon is further substantiated by several additional retrogradations that pace the Triassic, a period prone to such events.     

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.     

First Record of Theropod and Ornithopod Tracks and Detailed Description of Sauropod Trackways from the Tacuarembó Formation (Late Jurassic-?Early Cretaceous) of Uruguay

The record of dinosaur tracks and trackways from the Tacuarembó Formation (Late Jurassic-?Early Cretaceous) is described in detail: two trackways and four isolated tracks. Ichnites are preserved in sandstones of interdune facies of the Batoví (lower) Member. The interpretation herein presented indicates a sauropod affinity of the trackways, while the isolated prints are considered to have been made by an ornithopod and small theropods. The fossil record for this formation was primarily integrated by fresh-water organisms. The presence of new groups (sauropods and ornithopods) has specially contributed to the reconstruction of the terrestrial fauna, represented up until this time only by theropods.     

Transgressive–regressive sequences on the slope of an isolated carbonate platform (Middle–Late Permian, Laibin, South China)

From the Middle to Late Permian, the Laibin area in Guangxi, South China, was situated on the slope of an isolated carbonate platform, on which continuous marine successions were deposited. Two global stratotype sections for the boundary between the Guadalupian (Middle Permian) and Lopingian (Late Permian) are located at Penglaitan and Tieqiao in the Laibin area, respectively, and thus are chosen for study. At the two locations, 14 facies are recognized in the Maokou and Heshan Formations, and they are further grouped into four facies associations (basin, lower slope, upper slope, and platform margin). Six main transgressive–regressive (TR) sequences are identified in strata from the Roadian (Middle Permian) to the Wuchiapingian (Late Permian). They are conformable marine sequences that were little influenced by regional uplift (Dongwu Movement) and so provide a good record of the sea-level changes in South China at this time. Based on the significant taxonomic selection and controversial marine faunal loss in the end-Guadalupian mass extinction, and the Middle-Late Permian sea-level changes recorded by the TR sequences in the Laibin area, it is suggested that this extinction event might have been triggered by the reduction and loss of shallow-marine habitat area caused by the end-Guadalupian regression. The global cooling and Emeishan volcanism also occurring at this time could have further enhanced this extinction event.