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Nineteen ostracode species, belonging to 14 genera, including one unidentified genus are recorded from the upper Lower and Middle Members of Jhuran Formation, Mainland Kachchh, Gujarat, India for the first time. Two species—Majungaella perforata Grekoff and Pirilebris tenuisulcata Mette et Geiger—are assigned to already known taxa, and three species—Lophocythere? jhuranensis, Macrodentina jaduraensis and Patellacythere lineata—are described as new by two of the authors (M.K. and T.M.); and fourteen species are left in open nomenclature. Based on the distribution of the fauna, one ostracode biozone Macrodentina jaduraensis Taxon-range Zone has been proposed for the beds of upper Lower and Middle Members of Jhuran Formation and a Middle-Upper Kimmeridgian age is assigned for the zone. [ABSTRACT FROM AUTHOR]

This is the first record of the biggest Metriorhynchidae, aff. Plesiosuchus sp. in France. The remains consist of a partial vertebral column consisting of 11 vertebrae and an ischium fragment. A new method is proposed to evaluate the individual's size, which is estimated at 6.5 m. This method, unlike previous approaches, is based only on vertebrae and yields results that are congruent with those based on cranial remains. The state of preservation has allowed us to test the animal's 'profile of locomotion' to better interpret how it moved. Concerning other metriorhynchids, the record of Dakosaurus in France based only on teeth must be reassessed, and the genus Torvoneustes, if valid, has to be distinguished from Plesiosuchus. [ABSTRACT FROM AUTHOR]

Vertebrate palaeoichnology often aims at the identification of the trackmaker by associating diagnostic features from the known taxa’s skeletal anatomy with its inferred footprint morphology, but deep penetrative tracks and/or deep, detached undertracks (DDU) are providing conflicting morphological/extra-morphological information, bringing into question the initially assumed close anatomical correlation. Penetrative footprints produced in fluvial-dominated deltaic facies from Upper Jurassic Lastres Formation are very frequent in the coastal cliffs of Asturias (N Spain). Some of them consist of non-avian theropod track casts associated with “ornithopod-like” detached undertracks. Some criteria are suggested to distinguish the latter when such an association does not exist. Moreover, we describe an exceptional theropod footprint preserved as a sandstone cast along with its respective deep detached sandstone undertrack (DDSU). The specimen records the foot movement through the sediment, entailing striking morphologic changes in outline along four different levels of depth. The uppermost level 1 shows an apparent stegosaur hind track morphology; level 2 resembles an avian-theropod print; level 3 represents the true non-avian theropod pedal morphology of the trackmaker; the lowermost level 4 corresponds to the deep detached sandstone undertrack (DDSU), which could be interpreted as either a track of a graviportal theropod or an ornithopod-like footprint. In light of this new evidence, it becomes clear that vertebrate ichnotaxonomy should not be based solely on the supposed trackmaker identification. Furthermore, biogeographic and evolutionary studies linked to this core information should be considered unsupported, along with many ichnotaxonomical assignations based on taphonomic processes, such as the case exemplified herein, the Iguanodontipus ichnogenus.

Metriorhynchids are marine crocodylomorphs found across Jurassic and Lower Cretaceous deposits of Europe and Central and South America. Despite being one of the oldest fossil families named in paleontology, the phylogenetic relationships within Metriorhynchidae have been subject to many revisions over the past 15 years. Herein, we describe a new metriorhynchid from the Kimmeridgian of Porrentruy, Switzerland. The material consists of a relatively complete, disarticulated skeleton preserving pieces of the skull, including the frontal, prefrontals, right postorbital, nasals, maxillae, right premaxillae and nearly the entire mandible, and many remains of the axial and appendicular skeleton such as cervical, dorsal, and caudal vertebrae, ribs, the left ischium, the right femur, and the right fibula. This new specimen is referred to the new species Torvoneustes jurensis sp. nov. as part of the large-bodied macrophagous tribe Geosaurini. Torvoneustes jurensis presents a unique combination of cranial and dental characters including a smooth cranium, a unique frontal shape, acute ziphodont teeth, an enamel ornamentation made of numerous apicobasal ridges shifting to small ridges forming an anastomosed pattern toward the apex of the crown and an enamel ornamentation touching the carina. The description of this new species allows to take a new look at the currently proposed evolutionary trends within the genus Torvoneustes and provides new information on the evolution of this clade. [ABSTRACT FROM AUTHOR]

The Middle Jurassic–Early Cretaceous evolution of the Neuquén Basin is traditionally attributed to a long phase of thermal subsidence. However, recent works have challenged this model. In view of this, we study the Late Jurassic Tordillo Formation, a non‐marine depositional unit that marks a shift to regional regression across the basin. Previous studies propose different causes for this regression, including the growth of the magmatic arc in the west, uplift in the south or extension in the north. We studied the Tordillo Formation in sections located at an intermediate position in the Neuquén Basin, in order to understand the tectonic processes active during sedimentation. We present evidence of normal faulting within the Tordillo Formation and the base of the overlying Vaca Muerta Formation. Some of these faults can be attributed as syndepositional. We characterize the Tordillo Formation as part of a distal fan‐playa lake depositional system with a contemporaneous western magmatic arc as the main source of sediment. When compared to the Late Triassic–Early Jurassic NE to NNE‐oriented rifting, which marks the opening of the Neuquén Basin, the Late Jurassic extension shows a switch in stress orientation; the latter is orthogonal to the north‐trending subduction zone. We interpret this change as a renewed phase of back‐arc extension induced by slab rollback along with minor distributed intraplate extension prior to opening of the South Atlantic Ocean. [ABSTRACT FROM AUTHOR]

Four isolated cervical vertebrae from the Kimmeridge Clay Formation (Upper Jurassic, Kimmeridgian) of Abingdon, Oxfordshire, England are identified as from a pliosaurid plesiosaurian sauropterygian on account of their shortness relative to width and height, their near platycoelous nature and the location of tall rib facets on the centrum body. They are noteworthy for their size, with a maximum width of 269 mm, maximum height of 222 mm and maximum length of 103 mm. Simple scaling and comparisons with cervical vertebrae of Mid Jurassic pliosaurs Peloneustes and Liopleurodon , and the Early Cretaceous Stenorhynchosaurus and Sachicasaurus suggest a total body length of between ~ 9.8 m and 14.4 m for the Abingdon Kimmeridge Clay pliosaur. Likely the true length was towards the higher end of this range. A genus and species cannot be confidently determined on the basis of the described material, but they likely belong to Pliosaurus sp. or a similar animal, for which a precise neck length is not known. We estimate a neck length of 0.77 m for Pliosaurus ? brachyspondylus based on the average cervical lengths provided for specimen CAMSM J.35991. [ABSTRACT FROM AUTHOR]

The Late Jurassic-Early Cretaceous (164–100 Ma) represents one of the main transitional periods in life history. Recent studies unveiled a complex scenario in which abiotic and biotic factors and drivers on regional and global scales due to the fragmentation of Pangaea resulted in dramatic faunal and ecological turnovers in terrestrial and marine environments. However, chondrichthyan faunas from this interval have received surprisingly little recognition. The presence of numerous entire skeletons of chondrichthyans preserved in several localities in southern Germany, often referred to as Konservat-Lagerstätten (e.g., Nusplingen and the Solnhofen Archipelago), provides a unique opportunity of to study the taxonomic composition of these assemblages, their ecological distributions and adaptations, and evolutionary histories in detail. However, even after 160 years of study, the current knowledge of southern Germany's Late Jurassic chondrichthyan diversity remains incomplete. Over the last 20 years, the systematic study and bulk sampling of southern Germany's Late Jurassic deposits significantly increased the number of known fossil chondrichthyan genera from the region (32 in the present study). In the present work, the fossil record, and the taxonomic composition of Late Jurassic chondrichthyans from southern Germany are reviewed and compared with several contemporaneous assemblages from other sites in Europe. Our results suggest, inter alia, that the Late Jurassic chondrichthyans displayed extended distributions within Europe. However, it nevertheless also is evident that the taxonomy of Late Jurassic chondrichthyans is in urgent need of revision. [ABSTRACT FROM AUTHOR]

The bivalve fauna of the Upper Jurassic (Kimmeridgian) successions belonging to the Daïa and Nador mountains (NW Algeria) is taxonomically described and figured. For the first time, sixteen bivalve taxa were identified, partly in open nomenclature because of their poor state of preservation. Most taxa are represented by internal casts. The fauna was collected from two different formations of the same age: the Dolomies de Tlemcen Formation in the Daïa Mountains and the Faïdja Formation in the Nador Mountains. The lithologic characteristics of these formations, together with their fossil content and taphonomic features, confirm that these localities are characterized by marine conditions. The north-western Algerian bivalve assemblage holds the largest portion of cosmopolitan species. [ABSTRACT FROM AUTHOR]

The Jurassic formations within the Essaouira − Agadir Basin are of considerable interest for petroleum exploration, owing to their reservoir facies and hydrocarbon potentiality. These formations exhibit a scarcity of macrofossils, and their age is determined through lithological correlation. The Agadir − Essaouira Basin is a Mesozoic − Cenozoic sedimentary basin, part of the Tethyan Realm, precisely belonging to the Central Atlantic province which extends the Tethys westward. The material studied originates from five boreholes (GTE-1, MKL-110, NDK-2, NDK-3 and ESS-1) located at the center the basin along an East−West axis. The organic residue of the studied samples revealed a diverse dinoflagellate cyst assemblage with specific associations incorporating globally recognized marker taxa. The Early Callovian is distinguished by species such as: Ctenidodinium combazii , Ctenidodinium continuum, Ctenidodinium cornigerum , Dichadogonyaulax sellwoodii, and Impletosphaeridium varispinosum. The Late Callovian is characterized by the presence of marker cysts including: Compositosphaeridium polonicum, Endoscrinium galeritum Gonyaulacysta centriconnata, Liesbergia liesbergensis, Wanaea thysanota. The Early Oxfordian is marked by the association of species including: Gonyaulacysta jurassica subsp. jurassica , Rhynchodiniopsis cladophora , Scriniodinium crystallinum, Systematophora areolata , Systematophora penicillata , and Trichodinium scarburghense. The Late Oxfordian to basal Kimmeridgian is characterized by an association of dinoflagellate cysts including: Cribroperidinium globatum, Dichadogonyaulax? panneum, Downiesphaeridium polytrichum, Egmontodinium polyplacophorum, Endoscrinium galeritum , Gochteodinia mutabilis, Perisseiasphaeridium pannosum, Prolixosphaeridium anasillum, Scriniodinium crystallinum, Systematophora areolata, Systematophora penicillata, Surculosphaeridium vestitum, Systematophora? daveyi, and Wallodinium krutzschii. Our associations have been correlated with those in contemporary basins within other paleogeographic realms, contributing to the formulation of a global paleobiogeographic pattern. This pattern complements previous research on the distribution of dinoflagellate cysts during the Callovian − Early Kimmeridgian time interval. • Jurassic sections of five boreholes in Essaouira − Agadir Basin of Moroccan Atlantic Margin were studied palynologically. • The studied wells are palynostratigraphically correlated with that in other palaeogeographic areas. • Contribution to the reconstruction of the global palaeobiogeographic pattern of the distribution of dinoflagellate cysts. [ABSTRACT FROM AUTHOR]

The paper presents description of the eleven species of the subgenus Taramelliceras (Taramelliceras) Del Campana 1904 found in the Formation of "Acanthicum Beds" (Kimmeridgian) from Ghilcoș (Hăghimaș Mountains, Romania). The species T. trachinotum (Opp.), T. erycinum (Gemm.), T. mikoi (Herb.) and T. pugile (Neum.) have been previously described from this region by previous authors, the last two (T. mikoi and T. pugile) being recorded for a first time and one, (T. pugile pseudopugile Sarti), is determined on the base of specimens from Preda Colection In addition to the species listed, now there are six other species that enrich the association: T. greenackeri (Moesch), T. pseudoflexuosum (Fav.), T. cf. platyconcha (Gemm.), T. af. subcallicerum (Gemm.) and T. pugilepugiloides (Canav.), unknown in the region until now. [ABSTRACT FROM AUTHOR]

Pterodactylus from the uppermost Jurassic of southern Germany represents one of the most iconic pterosaurs, due to its status of being the first member of the Pterosauria to have been described and named. During the early phase of pterosaur research, Pterodactylus was a wastebasket taxon containing dozens of sometimes distantly related assigned species. Decades later, a comprehensive revision of the genus significantly reduced the number of species. To date, only one species remains in the genus, Pterodactylus antiquus, although the referral of several specimens to this taxon and the taxonomic relationships of them is still debated. Thus far, the genus has been only reported from the Upper Jurassic Plattenkalk deposits of Bavaria, and all of these occurrences are Tithonian in age. Here we describe the first record of Pterodactylus from the Torleite Formation near Painten (Bavaria), which represents the first occurrence of the genus from the Kimmeridgian. The specimen is a complete, articulated and exquisitely preserved skeleton of a small-sized individual. Aside from its old geological age, it is a typical representative of the genus, greatly resembling other specimens from younger strata. Certain characters, such as the overall size, skull length, relative orbit size, and phalangeal formula indicate that the specimen from Painten represents a juvenile to young subadult individual, an ontogenetic stage rarely found among Pterodactylus specimens. The find significantly expands the temporal range of the taxon and represents one of the best-preserved specimens of the genus reported so far. [ABSTRACT FROM AUTHOR]

The Kimmeridgian Alcobaça Formation of the Lusitanian Basin forms a mixed carbonate–siliciclastic unit between basinal deposits of the Abadia Formation, and fluvial–terrestrial strata of the Lourinhã Formation. This study presents >2.5 km of detailed logs of nine outcrop sections of the Alcobaça Formation in its type region. Eight of these sections encircle the Caldas da Rainha Diapir, which was a prominent, emergent, passive salt diapir during the time of deposition. Palaeoenvironments of the unit form a complex mosaic of low- to high-energy, carbonate- or siliciclastic-dominated shallow shelf settings; coastal embayments and lagoons; and coastal plains with rivers, lakes and playas. In the strata, abundant microfauna is often joined by a rich macrofauna, usually dominated by bivalves. Locally, corals, calcareous sponges or oysters form meadows or patch reefs. These autochthonous to parautochthonous remnants of former communities are assigned to 35 benthic macrofaunal associations. The integration of palaeoecological analysis of these associations with microfaunal and sedimentological data provides constraint on their salinity ranges, which range from slightly hypersaline to freshwater. Frequent temporal and spatial salinity fluctuations are attributed to variations in relative sea-level, salt tectonics or climate. The NNE-trending Caldas da Rainha Diapir induced pronounced facies differentiation. Predominantly, non-marine siliciclastic facies in the northwest and carbonate to siliciclastic, marine to brackish facies in the southwest are contrasted by shallow-marine carbonate facies east of the diapir. Comprehensive exposure and well-preserved fossils make the Alcobaça Formation an excellent showcase to demonstrate how biofacies analysis can help to disentangle the interplay of climate changes, sea-level fluctuations and salt tectonics. Based on the improved characterisation of the unit, the Alcobaça Formation is formally defined, and seven members are established. [ABSTRACT FROM AUTHOR]

Ichnogeneric classification of sauropod trackways is determined using qualitative and quantitative descriptions of morphological parameters. More recently, the validity of several of these parameters has been called into question (e.g., trackway gauge). This paper aims to test traditional and more novel landmark-based geometric morphometric (GM) analysis to describe sauropod tracks and trackways. The Courtedoux-Tchâfouè (TCH) tracksite, in NW Switzerland, has been used as a test site because it hosted several Late Jurassic sauropod track-bearing levels, over a short time period (∼40 ka), creating a time capsule of sauropod activity. Exploratory statistical analyses suggest that the TCH trackway dataset can be partitioned into clusters based on trackway parameters (e.g., width of pes angulation pattern/pes length) that demonstrate differences between trackways. Nevertheless, clustering reflected a moderate degree of intercluster similarity and a continuum in TCH trackway morphologies. The GM analysis of TCH pes impressions, from several trackways, indicates a similar morphotype and did not significantly differentiate pes tracks from various stratigraphic levels. Currently, the results indicate that neither linear nor landmark-based geometric morphometric methods strongly segregate tracks at TCH nor show a time-control (i.e., via stratigraphic level) over the short interval studied. The methods reinforce that sauropod pes impression shape is conservative and that combining morphological methods to be inclusive of sauropod trackway data is important. The TCH site demonstrates that variability may reflect morphological continuums and behavioural factors and does not unambiguously differentiate unique sauropod trackmakers. More exploration on the minimum number of trackway parameters as predictors of sauropod ichnotaxonomy is needed. Integrating complementary techniques will provide more insight and practical means of identification and delineation of sauropod tracks and their trackways.

The up to 450 m-thick Upper Jurassic Lemeš Formation includes organic-rich deep-water (max. ~ 300 m) sedimentary rocks deposited in the Lemeš Basin within the Adriatic Carbonate Platform (AdCP). The Lemeš Formation was investigated regarding (1) bio- and chemostratigraphy, (2) depositional environment, and (3) source rock potential. A multi-proxy approach—microfacies, Rock–Eval pyrolysis, maceral analysis, biomarkers, and stable isotope ratios—was used. Based on the results, the Lemeš Formation is subdivided from base to top into Lemeš Units 1–3. Deposition of deep-water sediments was related to a late Oxfordian deepening event causing open-marine conditions and accumulation of radiolarian-rich wackestones (Unit 1). Unit 2, which is about 50 m thick and Lower early Kimmeridgian (E. bimammatum to S. platynota, ammonite zones) in age, was deposited in a restricted, strongly oxygen-depleted basin. It consists of radiolarian pack- and grainstones with high amounts of kerogen type II-S organic matter (avg. TOC 3.57 wt.%). Although the biomass is predominantly marine algal and bacterial in origin, minor terrestrial organic matter that was transported from nearby land areas is also present. The overlying Unit 3 records a shallowing of the basin and a return to oxygenated conditions. The evolution of the Lemeš Basin is explained by buckling of the AdCP due to ophiolite obduction and compressional tectonics in the Inner Dinarides. Lemeš Unit 2 contains prolific oil-prone source rocks. Though thermally immature at the study location, these rocks could generate about 1.3 t of hydrocarbon per m2 surface area when mature. [ABSTRACT FROM AUTHOR]

Forty gastropod species of the subclass Heterobranchia are described from the Upper Jurassic (Upper Kimmeridgian) reefal limestones of South Germany, including ten species in open nomenclature and further ten species of uncertain identity. Six species are new to science: Ceritella convexa sp. nov., Nerinea donosa sp. nov., Endoplocus acutus sp. nov., Endoplocus inflatus sp. nov., Pseudonerinea? pseudomelaniformis sp. nov., and Itieroptygmatis cylindrata sp. nov. A lectotype is designated for Ptygmatis? tornata (Quenstedt, 1852). With this final part of the study of the Late Jurassic gastropods from Saal and the Nattheim area, a total of 156 species have been reported. Of these species, 125 have been reported from Saal and 54 from the Nattheim area. Only 23 species occur in both Saal and the Nattheim area. The sample sizes (number of specimens) from Saal and the Nattheim area differ considerably and few species are shared. Diversity metrics suggest the same high diversity at both sites. The gastropod fauna from the Saal quarry has yielded particularly much new information - all new species are based on specimens from Saal. With 125 gastropod species from a single outcrop, the diversity at the Saal quarry is the highest from the Kimmeridgian worldwide. In total, up to 300 species of marine macro-invertebrates have been reported from this quarry, which is a very high point diversity. Gastropods are by far the most diverse group from Saal, which is a modern aspect of this fauna. [ABSTRACT FROM AUTHOR]

Here, we provide a detailed taxonomic reassessment of a historically collected chondrichthyan dental assemblage from the lower Kimmeridgian of Czarnogłowy in north-western Poland and discuss its significance for better understanding hybodontiform diversity patterns prior to their post-Jurassic decline in fully marine environments. In spite of its low taxonomic diversity, consisting of four large-toothed taxa (viz., Strophodus udulfensis, Asteracanthus ornatissimus, Planohybodus sp. and cf. Meristodonoides sp.), this assemblage is remarkable in that there are only very few Mesozoic hybodontiform assemblages with more large-toothed genera or even species. Comparisons with other European Late Jurassic hybodontiform-bearing localities demonstrate fairly homogenous distribution patterns characterized by large-bodied epipelagic forms of high dispersal ability. This is in stark contrast to post-Jurassic hybodontiform associations, which are dominated by smaller species that were predominantly bound to marginal marine and continental waters, suggesting a major reorganization of chondrichthyan communities during the Early Cretaceous.

Here, we provide a detailed taxonomic reassessment of a historically collected chondrichthyan dental assemblage from the lower Kimmeridgian of Czarnogłowy in north-western Poland and discuss its significance for better understanding hybodontiform diversity patterns prior to their post-Jurassic decline in fully marine environments. In spite of its low taxonomic diversity, consisting of four large-toothed taxa (viz., Strophodus udulfensis, Asteracanthus ornatissimus, Planohybodus sp. and cf. Meristodonoides sp.), this assemblage is remarkable in that there are only very few Mesozoic hybodontiform assemblages with more large-toothed genera or even species. Comparisons with other European Late Jurassic hybodontiform-bearing localities demonstrate fairly homogenous distribution patterns characterized by large-bodied epipelagic forms of high dispersal ability. This is in stark contrast to post-Jurassic hybodontiform associations, which are dominated by smaller species that were predominantly bound to marginal marine and continental waters, suggesting a major reorganization of chondrichthyan communities during the Early Cretaceous. [ABSTRACT FROM AUTHOR]