Stratigraphic Distribution Research Articles

A new carcharodontosaurid specimen sheds light on the anatomy of South American giant predatory dinosaurs.

Carcharodontosaurids were gigantic terrestrial dinosaurs and top predators of dinosaur faunas in Gondwanan landmasses during the "Mid"-Cretaceous Period. Despite their wide geographical and stratigraphical distribution, essential parts of their anatomy are still poorly known. The present contribution aims to describe a new partial skeleton of the carcharodontosaurid Taurovenator violantei, which was previously known only by an isolated postorbital bone coming from Cenomanian-Turonian beds of northern Patagonia, Argentina. The neck of Taurovenator is composed of notably high anterior cervicals, bearing neural spines with expanded, flange-like dorsal tips which are successively imbricated. This condition has been reported previously in the carcharodontosaurid Acrocanthosaurus, but its occurrence in Taurovenator and other members of the clade suggests it may represent a synapomorphy of this theropod family. This unique neck morphology was probably related to strong modifications in musculature and restriction in the range of movements within the neck, but not with the head. The new specimen also affords valuable anatomical information on the forelimb of Patagonian carcharodontosaurids. As in other giganotosaurines, Taurovenator shows strongly reduced forelimbs, particularly the forearm, showing hand elements with elongated non-ungual phalanges, and well-marked articular surfaces and muscular insertions, suggesting highly movable digits. This new specimen of Taurovenator allows us to expand anatomical and morpho-functional discussions about the carcharodontosaurid clade.

Evidence for a floristically diverse rainforest on the Falkland archipelago in the remote South Atlantic during the mid- to late Cenozoic

Abstract We report the discovery of an ancient forest bed near Stanley, on the Falkland Islands, the second such ancient deposit identified on the South Atlantic island archipelago that is today marked by the absence of native tree species. Fossil pollen, spores and wood fragments preserved in this buried deposit at Tussac House show that the source vegetation was characterized by a floristically diverse rainforest dominated by Nothofagus-Podocarpaceae communities, similar to cool temperate Nothofagus forests/woodlands and Magellanic evergreen Nothofagus rainforests. The age limit of the deposit is inferred from the stratigraphic distribution of fossil pollen species transported by wind, birds or ocean currents from southern Patagonia, as well as similar vegetation types observed across the broader region. The deposit is suggested to be between Late Oligocene and Early Miocene, making it slightly older than the previously analysed Neogene West Point Island forest bed (200 km west of Tussac House). The combined evidence adds to our current knowledge of the role of climate change and transoceanic dispersal of plant propagules in shaping high-latitude ecosystems in the Southern Hemisphere during the late Palaeogene and Neogene.

Tubeworms as bioindicators of paleoenvironmental conditions

Tubeworms comprise an informal designation for a biological group of marine invertebrates, associated with producing rigid tubes around their body with varied compositions and functions. The main representatives of this group currently comprise organisms from different phyla and have a wide stratigraphic distribution, taxonomic and biostratigraphic discussions have always been related to the group, not presenting themselves in a distinct way for the Devonian of the Paraná Basin. In the present work, we recognize the taxa Annulitubus mutveii, Cornulites auxilium, and a polychaete agglutinating of the order Terebellida occurring in all lithofacies of the lower shoreface to the offshore from Late Praguian to Givetian. In addition, we discuss the potential of Annulitubus mutveii as a paleoenvironmental bioindicator associated with ecologically stressed environments caused by post-biotic crises caused by extinction events.

Identifying driving factors and their interacting effects on accumulation of heavy metals in cultivated soils based on optimal parameter geographic detector model

Identifying the factors and their interactive effects on soil heavy metals (HMs) accumulation in karst areas is a significant challenge in preventing and controlling soil contamination by HMs. A total of 1043 topsoil (0–20 cm) samples were collected from northwestern Guizhou to determine the concentrations of HMs (Cd, Pb, Zn, Cr, Cu, and Ni). Then, the optimal parameter based geographic detector (OPGD) model was used to identify the driving factors and interactions of natural variables (such as strata, soil organic matter, terrain, etc.) and human activity variables (such as distance from mining sites (DFM), distance from road (DFR), population density (DOP), etc.) on the spatial accumulation of soil HMs in the region. The findings revealed that the average concentrations of all HMs exceeded the corresponding background values of soil in Guizhou Province. Cd had the highest accumulation, followed by Cu, Ni, and Cr. Moran's I and inverse distance interpolation results showed clear clustering trends in the spatial distribution of HMs. The high-high clusters of Cd, Pb, and Zn were concentrated in the northern and southern parts of the study area, while the high-high clusters of Ni, Cr, and Cu were distributed mainly in the eastern and western parts of the study area. OPGD analysis results indicated that soil Cd, Pb, and Zn accumulation was influenced primarily by SOM, DFM, and stratigraphic distribution, followed by pH and soil type. Whereas Ni, Cr, and Cu were mainly affected by stratigraphic distribution. Additionally, DOP, terrain, and soil type were secondary factors affecting the accumulation of these three types of HMs. Notably, the interactive effects among these factors were found to have a more significant impact on HMs accumulation than individual factors alone. Overall, this study provides valuable insights into the main factors influencing the spatial distribution of HMs and their interactive relationships, contributing to the theoretical basis for preventing and controlling HMs pollution in the study area.

Eocene larger benthic Foraminifera from the Jahrum Formation (Kalbibak Section, Boldaji Region) in High Zagros, Iran: an approach on paleontology and biostratigraphy

The Jahrum Formation is a major Eocene carbonate deposit of High Zagros in the west of Iran. It consists of thin bedded to thick massive limestone, accumulated on a shallow marine platform within the Neo-Tethys Ocean realm. Fifty-five surface samples were collected throughout a 215 m section in the Kalbibak area (Boldaji region, Chahar Mahal Bakhtiari province). The stratigraphic distribution of benthic foraminifers allows characterizing five foraminiferal biozones, which are in the following order: Alveolina aff. schwageri Taxon Range Zone, A. decastroi Taxon Range Zone, A. aff. frumentiformis–A. cf. stercusmuris Interval Zone, A. aff. stercusmuris–A. aff. fusiformis Interval Zone and Nummulites–Alveolina Assemblage Zone. The benthic foraminiferal associations in the studied area are similar to those recorded in Tethys realms and enable us to correlate the Jahrum Formation with the early to middle Eocene. Keywords: benthic foraminifers, biostratigraphy, Jahrum Formation, Kalbibak section, West Iran.

BIOSTRATIGRAPHY, PALEOENVIRONMENT AND HYDROCARBON POTENTIAL OF FIKA MEMBER OF PINDIGA FORMATION, GONGOLA SUB-BASIN, NORTHERN BENUE TROUGH, NE NIGERIA

The Fika Member, a crucial stratigraphic unit within the Pindiga Formation, represents a significant geological entity with substantial implications for understanding the regional paleoenvironmental evolution and hydrocarbon prospectivity. This study integrates biostratigraphic analyses, sedimentological investigations, and hydrocarbon potential assessments to elucidate the depositional history, paleoenvironmental conditions, and source rock prospect of the Fika Member. Facies and their stratigraphical distribution analyses were conducted on the Fika Shale exposed mainly at Gabukka Stream 1 and 2. Twenty (20) samples collected were subjected for standard palynological and foraminifera analyses. A standard method of palynomorphs extraction that involves the use of Hydrofluoric and Hydrochloric acid was employed. For foraminifera analysis, washing and sieving method was used. It was discovered that agglutinated foraminifera are the dominance taxa in ten (10) out the twenty (20) samples studied. Based on the colours of the agglutinated foraminiferal and Foraminiferal Color Index (FCI) values suggest low thermal maturity for both oil and gas generation. The foraminiferal assemblages indicate marginal marine (fluvio marine) to shallow inner neritic environments. This is supported by the sedimentological data which indicates a shallow marine depositional environment. The biostratigraphic data suggest Santonian age for the Fika Member.

Simulation of geological uncertainty based on improved three-dimensional coupled Markov chain model

The natural stratigraphic distribution is uncertain due to the geological tectonic movements and sedimentation. It is a challenge for traditional deterministic models to capture geological uncertainty. The objective of this study is to develop an improved three-dimensional coupled Markov chain (ICMC3D) model based on limited boreholes. The proposed method enhances the traditional three-dimensional coupled Markov chain model by modifying the transition probability equation for predicting unknown elements. The dip data is added to estimate the transition probability matrix with the borehole information. On this basis, a back analysis method is proposed for estimating the horizontal transition probability matrics. The method makes the predicted results more suitable for the possible stratigraphic distribution. The accuracy of the proposed method is verified through some applications. In this paper, an improved three-dimensional coupled Markov chain model and transition probability matrix estimation method are illustrated by the borehole data collected from a tunnel project in Qingdao. The results show that the presented method can reflect the asymmetry, continuity and anisotropy of the three-dimensional stratum. The exceedance probability is proposed to predict the fault zone development range in order to reduce the geological uncertainty.

New contributions to the taxonomy of non-marine ostracods from the Neogene megawetlands, western Amazonas state, Brazil

The taxonomic review of the ostracods from Solimões Formation in the western Amazonas State, Brazil, allowed the identification of eight genera and twenty-two species of the genus Cyprideis Jones, 1857. Two species are new: Cyprideis goeldiensis sp. nov and Cyprideis javariensis sp. nov.; and Cyprideis sp. 1 remains in open nomenclature. For the first time, the species Cyprideis santaelenae Sousa and Ramos 2023, originally described to the Pebas Formation, in Peru, was recorded in the Solimões Formation. A new morphotype of the species Cyprideis matorae Gross et al. 2014 is here identified. The stratigraphical distribution of the Cyprideis species in the borehole 1AS-32-AM permitted the identification of four ostracod zones: Cyprideis caraionae Zone, Cyprideis minipunctata Zone, Cyprideis cyrtoma Zone and Cyprideis paralela Zone, presenting a time range from the middle Miocene (Serravallian) to the late Miocene (Tortonian). Based on the ostracod assemblage, an environment of a semiconfined lake, with mesohaline features and sporadic marine influence is attested to the western Amazonia during the Miocene. The species turnover of Cyprideis occurred during the Tortonian.

Late Holocene echinoderm assemblages can serve as paleoenvironmental tracers in an Antarctic fjord

High Latitude fjords can serve as sediment trap, bearing different type of proxies, from geochemical to micropaleontological ones, making them exceptional tools for paleoenvironmental reconstruction. However, some unconventional proxies can be present and can be used to depict a comprehensive and exhaustive interpretation of past changes. Here, studying a sediment core in Edisto Inlet (Ross Sea, Antarctica) we used irregular echinoid spines and ophiuroids (Ophionotus victoriae) ossicles to trace environmental changes throughout the last 3.6 kyrs BP. Irregular echinoids can serve as proxy for the organic matter content, while O. victoriae ossicles can be used as proxy for steady sea-ice cycle along with organic deposition events. O. victoriae release a high number of ossicles, making estimation about the population quite challenging; still, presence data, can be easily collected. By applying Generative Additive Models to the stratigraphical distribution of these data, we detected an environmental phase that was previously unnoticed by other traditional proxies: the Ophiuroid Optimum (2–1.5 kyrs BP). In conclusion, here we demonstrate how echinoderm presence can be used as a valuable source of information, while proving the potential of modelling binary data to detect long-term trend in Holocene stratigraphical records.

Anagenesis and the tyrant pedigree: A response to “Re-analysis of a dataset refutes claims of anagenesis within Tyrannosaurus-line tyrannosaurines (Theropoda, Tyrannosauridae)”

Taxonomic diversity in the derived tyrannosaurine Daspletosaurus has been hypothesized to represent a variety of evolutionary patterns by different authors. The recent description of D. wilsoni, the third species of this genus, was proposed to support the paraphyly of Daspletosaurus and participation of its species within a single anagenetic lineage terminating at the base of a clade formed by Tyrannosaurus and other gigantic tyrannosaurines (Tarbosaurus, Zhuchengtyrannus). However, a recent reanalysis including additional data has challenged this interpretation, instead recovering Daspletosaurus as a monophyletic sister group to Tyrannosaurus and its closest relatives, characterized by several cladogenetic events. Here we show that incorporating further data and correcting erroneous interpretations of relevant anatomical features overturns this result. Using a novel phylogenetic analysis including additional specimens, we recover a paraphyletic Daspletosaurus, with species of this genus forming successive sister taxa to Tyrannosaurus-line tyrannosaurines. This result facilitates an interpretation of currently recognized Daspletosaurus species as representing a single anagenetic lineage, in agreement with the stratigraphic distribution of relevant specimens and a qualitative analysis of the range of morphological variation observable within D. wilsoni.

OIL FAMILIES AND GEOCHEMICAL COMPOSITION OF DEVONIAN OILS AT THE RECHITSA FIELD, PRIPYAT BASIN, BELARUS

The sedimentary column at the Rechitsa oilfield in the Pripyat rift basin, Belarus, is dominated by an Upper Devonian synrift succession. The succession includes uppermost Frasnian and mid‐Famennian salt units which are about 1000 m and 2000 m thick respectively. Reservoir rocks consist of sandstones and carbonates in the intra‐, inter‐ and sub‐salt successions. In this paper, the geochemical analysis of 15 oil samples from different stratigraphic intervals at the Rechitsa field is used as a basis for reservoir characterisation. Geochemical studies included biomarker and stable C, N and S isotope analyses.Four genetic oil groups were identified and are referred to as Groups A to D. Oils in Group A came from upper intra‐ and inter‐salt reservoir rocks; the oils are early mature, enriched in heavy (C36+) hydrocarbons, heteroatoms, aryl‐isoprenoids and gammacerane, with low Pr/Ph = 0.6 and a sulphur isotope composition averaging 22.7‰ CDT. Oils in Group B were from sub‐salt reservoirs and are at peak maturity with Pr/Ph = 1, an increased proportion of C27 regular steranes, and a sulphur isotope composition of 8.1‰ CDT. The single oil sample in Group C was from a Proterozoic reservoir. The oil was overmature with a low content of heavy fractions, heteroatoms and steranes; its hopanes composition indicated that it was generated by the same source rock as the oils in Group B. Oils in Group D came from inter‐salt reservoir rocks and were composed of a mixture of Groups A and B oils in roughly equal proportions, as indicated by their average isotope, molecular and biomarker compositions.Observed differences in oil composition were explained in terms of contributions from at least two different source rocks together with variations in source rock maturity. Group A oils were interpreted to have been generated by Famennian carbonate‐rich source rocks containing dominantly marine and bacterial organic matter deposited in an anoxic evaporitic setting. Source rocks for Groups B and C oils were suggested to be composed of OM‐rich marine shales of Frasnian age or older.The geochemical characteristics of the Devonian oils from Rechitsa field, and the oil‐oil and oil‐ source rock correlations reported, will contribute to a better understanding of the petroleum system in the Pripyat Basin although direct oil‐ source rock correlations are not yet available. The presence of at least two source rocks for the Rechitsa oils has been suggested, respectively comprising carbonates in the inter‐salt succession and marine shales and/or carbonates in the sub‐salt succession. The main controls on oil composition in the Devonian reservoir units were the varying contributions from the different source rocks and differences in source rock thermal maturity associated with variations in burial depth and tectonics, together with the stratigraphic distribution of reservoir units which was in turn controlled by the presence of the thick Frasnian and Famennian salt units.

First theropod footprint identified in the middle Kimmeridgian of Buarcos (West Central Portugal): scientific and educational implications

ABSTRACT A dinosaur track was recently discovered at Buarcos (Figueira da Foz, Portugal). The stratigraphic level is in the upper part of the Boa Viagem Sandstone Formation, and the specimen is the first evidence for the presence of middle Kimmeridgian dinosaurs in the Cabo Mondego area. This track reveals a medium size theropod estimated with one meter height to the hip. Moderate dinoturbation indicate the presence of more than one dinosaur at that time. This finding suggests that Buarcos area may have a relevant ichnological fossil record, highlighting the importance of further works in this formation. It's also a good indicator for the presence of dinosaur remains which are poorly known in this time interval. Based on the currently known stratigraphic distribution of the theropod fossil record in the Upper Jurassic of the Lusitanian Basin, the trackmaker could have been either Ceratosaurus, Lourinhanosaurus or Allosaurus. The paleoenvironment is interpreted as a deltaic alluvial plain, with small to medium size migrating channels and flooding areas. The footprint has also didactic and aesthetic features which, on display in a museum, contribute to enhance cultural and educational activities. The context of the discovery of this specimen allows to address issues on the geological heritage.

Influence of geological uncertainty on longitudinal deformation of tunnel based on improved coupled Markov chain

The complex geological condition encountered during excavation is the key challenge for tunneling projects. Therefore, tunnel design and construction require a comprehensive understanding of the subsurface geology. This study aims to reveal the effect of geological uncertainty on tunnel longitudinal deformation based on a reconstruction geological model using the improved coupled Markov chain method. The improved coupled Markov chain method makes the predicted results more suitable for the possible stratigraphic distribution by optimizing the transition probability matrix, and breaks through the limitations of non-coaxial predicted cell updating in traditional methods. A mapping method was proposed to establish a matching relationship between the irregular grids of the geological model and the numerical tunnel model. Then, a long tunnel in Shenzhen was selected as a case study to demonstrate the effectiveness of the proposed framework. The correlation coefficient was used to verify the relationship between tunnel deformation and the surrounding stratum with different tunnel cover depths. The geological uncertainty of various strata was quantitatively measured based on the proposed geological uncertainty index. The three-dimensional strata surrounding the tunnel were reconstructed based on exceedance probabilities for adverse geological conditions. Quantitative analysis was conducted on the tunnel vertical convergence during the excavation process.

High-resolution UAV maps of the Gobi Desert provide new insights into the Upper Cretaceous of Mongolia

The Gobi Desert of southern Mongolia is home to an incredibly rich record of dinosaurs and other vertebrate fossils from the latest Cretaceous Period. Together, more than a dozen sites in several basins have produced one of the richest palaeofaunas known from this interval anywhere in the world. Most of this diversity has been recovered from the fluvial deposits of the Nemegt Formation. Despite historic and ongoing research in southern Mongolia, accurate maps and geological data for the main fossil sites are still lacking, limiting our ability to investigate how local palaeoecological dynamics influenced Nemegt taxa, their geographic distribution, and their evolutionary patterns. One of these sites, Guriliin Tsav, has produced more than a hundred significant fossil specimens to date, but still remains one of the lesser known Nemegt localities. In part this is because many expeditions have instead focused on the nearby Bügiin Tsav, one of the largest and richest localities for the Nemegt Formation. To address this gap, a project was initiated in 2018 to produce a high-resolution topographic map of Guriliin Tsav using Unmanned Aerial Vehicles (UAV), and consequently, to plot the geographic and stratigraphic distributions of palaeontological resources on this map. In so doing, we also collected stratigraphic and taphonomic data from the area, allowing for the first detailed palaeoecological interpretation of Guriliin Tsav and a comparison with other localities of southern Mongolia. Here we present the results of this project, and also discuss new topographic and stratigraphic data from Bügiin Tsav. This sheds new light into the temporal and geographic distribution of vertebrate taxa in the latest Cretaceous of Mongolia.

Variability of sequence architecture in a rift margin controlled by tectonic activity: The Eocene Dongying Depression, Bohai Bay Basin, China

AbstractSequence architectures along the margins of rift basins are still poorly documented compared to passive continental margin settings. The Eocene Shahejie Formation on the rift margin of the Dongying Depression records a complex sequence stratigraphic distribution of conglomerate, sandy conglomerate, sandstone and mudstone. These facies have been mainly attributed to fan delta and marginal subaqueous fan depositional settings that developed during segmented fault activity along the rift margin. We utilize three‐dimensional (3D) seismic data, conventional cores, and wireline log data to dissect the overall wedge‐shaped upper sub‐member strata of the Shahejie Formation's fourth member. The study interval is a third‐order sequence formed between 45.4 and 42.5 Ma and contains a lowstand–transgressive systems tract (LST–TST) and a highstand systems tract–falling‐stage systems tract (HST–FSST). We found that the LST–TST developed several huge amalgamated depocenters along the Chennan border fault; whereas, these depocenters gradually diminished or even disappeared during the HST–FSST period, illustrating less significant control by the border fault. Through calculations of strata growth rates, we confirmed that the segmented activity of the border fault influences the stratigraphic distribution and facies evolution during these two periods. Specifically, deep‐water depositional systems, represented by marginal subaqueous fans were widely developed in the LST–TST period and were influenced by overall strong tectonic activity, including retrogradational (R) and aggradational (A) patterns. However, the aggradational to progradational (AP) deltas and progradational to degradational (PD) deltas dominated the generally muted tectonic activity setting during the HST–FSST. Additionally, influenced by localized segmented fault activity, these systems tracts exhibit incomplete vertical development, resulting in spatial variability in stratigraphic stacking patterns.

Assessing the feasibility of laser induced breakdown spectroscopy for detecting nitrogen in martian surface sediments

Despite the detection of fixed nitrogen in meteorites and directly on Mars' surface, the abundance and distribution of nitrogen sequestered in the martian crust remains unknown. Given that nitrogen is a bioessential element that is required for the synthesis of amino acids, nucleic acids, and other organic molecules vital for life, this gap in knowledge is one of the most important challenges in constraining martian habitability. Laser-induced breakdown spectroscopy (LIBS) has the capability to detect N in natural rock samples and is available as a stand-off survey instrument on multiple currently active Mars rovers, creating an immediate opportunity to map the stratigraphic distribution of N within diverse depositional settings. However, little has been published regarding the detection of N with LIBS.To lay a foundation for N detection on Mars using LIBS, we synthesized a comprehensive suite of samples with variable amounts of nitrogen (as nitrate or ammonium) in either a Mars regolith simulant or a clay matrix. We present baseline spectra of N emission in Mars-relevant matrices and identify spectral interferences. Our results indicate that 17 diagnostic N emission lines are reliably detectable from mineral-bound N against a basaltic background, but only four lines exhibit sufficient sensitivity to be detected across a range of N concentrations and within all tested matrices. To elucidate optimized strategies for quantification, we present an iterative series of PLS models. We find that prediction accuracy is improved by restricting the compositional range of the training set, normalizing the data, subtracting baseline continuum emission, and simultaneously modeling the emission behaviour of multiple diagnostic N lines at once. We observe that the prediction uncertainty increases (worsens) from 8.4% to 29.9% if models are used to predict N in samples with a dissimilar matrix than those used during training, suggesting poor generalizability outside the training range. Consequently, future work should focus on developing a larger, more diverse training set that encompasses the range of N concentrations and phases expected to be encountered on Mars, which may be used to train generalizable models. Overall, this work demonstrates that LIBS is a promising tool for determining the abundance of N sequestered in martian surface materials and lays a foundation for future development.

Advanced mapping of inorganic treatments on porous carbonate stones by combined synchrotron radiation high lateral μXRPD and μXRF

Understanding the effects of consolidating inorganic mineral treatments on carbonate stones of cultural heritage, and on the nature and distribution of newly formed products within the matrix, poses a significant challenge in Heritage Science and Conservation Science. Existing analytical methods often fail to deliver spatial and compositional insights into the newly formed crystalline phases with the appropriate high lateral resolution. In this study, we explore the capabilities and limitations of synchrotron radiation (SR) micro-X-ray powder diffraction (μXRPD) mapping combined with micro-X-ray fluorescence (μXRF) to give insight into compounds formed following the application of ammonium oxalate (AmOx) and diammonium phosphate-based (DAP) solutions on porous carbonate stone. Ultimately, the integration of μXRPD mapping and μXRF analysis proved itself a powerful asset in providing precise qualitative and quantitative data on the newly formed phases, in the case of both calcium oxalates (CaOxs) and calcium phosphates (CaPs), and their complex stratigraphic distribution, thus opening a new route for applications to a more comprehensive study of inorganic treatments applied to carbonate substrates.

Orthoceratoid and coleoid cephalopods from the Middle Triassic of Switzerland with an updated taxonomic framework for Triassic Orthoceratoidea

Orthoconic cephalopods are subordinate, but persistent, widespread and regionally abundant components of Triassic marine ecosystems. Here, we describe unpublished specimens from the Anisian (Middle Triassic) Besano Formation at Monte San Giorgio, Switzerland. They can be assigned to two major but unrelated lineages, the Coleoidea and the Orthoceratoidea. The orthoceratoids belong to Trematoceras elegans (Münster, 1841) and occur regularly within the Besano Formation, are uniform in size, and have few available morphological characters. In contrast, coleoids are more diverse and appear to be restricted to shorter intervals. A new coleoid is described as Ticinoteuthis chuchichaeschtli gen. et sp. nov. To better put the orthoceratoids of the Besano Formation into perspective, we also synthesise the current taxonomy of Triassic orthoceratoids on a global scale. The currently used scheme is largely outdated, with very little taxonomic progress in the past 100 years. Despite previous research showing the distinctness of Triassic orthoceratoids from Palaeozoic taxa, they are still commonly labelled as “Orthoceras” or “Michelinoceras”, which are confined to the Palaeozoic. We show that Triassic orthoceratoids probably belong to a single lineage, the Trematoceratidae, which can be assigned to the Pseudorthocerida based on the embryonic shell and endosiphuncular deposits. Many Triassic species can probably be assigned to Trematoceras, but there are at least two additional Triassic orthoceratoid genera, Paratrematoceras and Pseudotemperoceras. Finally, we review the palaeobiogeographic and stratigraphic distribution of the group and outline possible future research directions.

Reevaluating the “elephant butchery area” at the Middle Pleistocene site of Notarchirico (MIS 16) (Venosa Basin, Basilicata, Italy)

The archaeological site of Notarchirico, chronologically placed at the end of MIS 17 and MIS 16 (675-610 ka), is a key site for studying Acheulean technology in southern Europe and gaining a better understanding of human occupation in that region during the Middle Pleistocene. It was excavated between 1979 and 1995 by Marcello Piperno and re-opened since 2016. Between 1990 and 1991, around forty remains of Palaeloxodon antiquus, mostly comprising the head of the animal, such as cranium, mandible and tusks fragments belonging to a sub-adult male were discovered as a result of the excavation of a lateral discontinuity of the level A, situated in an area known as the “elephant butchery area”. Remains of deer, mainly assigned to Dama sp., and 42 stone tools, including choppers, hand-axes, cores and some flakes were also identified in the surroundings. This accumulation was originally interpreted as a butchering site, reflecting a single event of processing of an elephant carcass, and the entire paleosurface was exposed to visitors in situ. This work re-evaluates the original archaeological materials, especially those still preserved on the paleosurface, in terms of stratigraphic distribution, taphonomy and technology, to critically evaluate the putative role of hominins in the exploitation of the megaherbivore. After a meticulous examination of each element's surface and its deposition, we conclude that there is no support for the previous interpretation of the so-called "elephant butchery area" of Notarchirico as the result a butchery event, as there is no evidence of human exploitation of the remains and the accumulation derives from at least two diverse and unrelated depositional events, one resulting in the deposition of the elephant remains, and the other of the majority of the fallow deer remains and the stone tools.

Geochemical study of a Neolithic metallurgical site, Le Planet (France): Detection of paleopollution recorded in archaeological soils

A geochemical study was carried out at the metallurgical site of Le Planet (Fayet, Aveyron), situated in the south of France. The site dates from the 3rd millennium BC, and is one the oldest copper smelting metallurgical sites known in France. The site reveals numerous phases of occupation, all dated from the Late Neolithic. The geochemical study of the site aimed at identifying the signature of the metallurgical activities in the archaeological soils and their spatial distribution. The analyses were carried out by X-ray fluorescence (p-XRF). Two main sampling methods were used. The first, grid-based method, allowed the sampling of the totality of the archaeological excavation surface. The second sampling method aimed to study the vertical distribution of the trace elements in the stratigraphic sequence. Four vertical profiles, positioned throughout the site, allowed a high-resolution sampling of the totality of the stratigraphy, which permitted to identify the stratigraphic distribution of polluted archaeological horizons. The geochemical analyses reveal the importance of the pollution due to the prehistoric metallurgical activities, mainly of lead, copper and arsenic. For instance, the measured values of lead vary between 26 and 9831 ppm. These values for copper are between 53 and 1154 ppm, whereas for arsenic they vary between 35 and 258 ppm. The metallurgical furnaces seem to constitute the main hotspots for the spatial distribution of the pollution. The geochemical study of the profiles identifies two main polluted archaeological horizons, and thus allows having a better understanding of the stratigraphic extension of horizons containing geochemical traces of metallurgical activities.