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The fossil remains of birds from the Miocene of Portugal are scarce, encompassing a total of twelve specimens, from nine paleontological outcrops located in Leiria (central Portugal), southern sector of Setúbal Peninsula and along the lower Tagus Basin. This study focuses on a new specimen found in the Praia do Penedo Norte (Sesimbra) coastal cliff corresponding to a coracoid bone, attributed to Morus sp., a sulid bird, biostratigraphically framed by calcareous nannofossils within the middle Miocene (Langhian).

The shallow marine carbonate deposits of the S. Miguel Formation in the Lusitanian Basin reveal erosional events exposing stiff substrates with abundant Bergaueria hemispherica . The ichnoassociation represented by B. hemispherica , Thalassinoides suevicus , Spongeliomorpha isp., Asterosoma ludwigae and Rhizocorallium commune is dated from lowermost Pliensbachian by the association with ammonites from the jamesoni Biozone, brevispina Subzone. The unlined forms of B. hemispherica include peripheral and bottom burrow concentrations of shell debris, annular-like structures in the burrow margin and paired burrows-to-linear clusters that are comparable with the penetrative burrowing mechanism, anchoring and feeding behaviours of sea anemones. From the ethological point of view, and comparing with modern behaviours of burrowing anemones, the B. hemispherica from the Lusitanian Basin may represent temporary burrowing and relocation of actiniarian anemones. Their comparison with either thenarian or athenarian actiniarians may evidence a preferred surficial feeding strategy on the organic-rich muddy sediments they burrowed.

The sedimentological and ichnological data of the Mila Group in the Alborz Basin, northern Iran indicate that the appearance of exotic facies and resurgence of microbialites resulted from the development of extraordinary palaeoceanographic conditions with widespread environmental stress and enhanced precipitation of CaCO 3 . Inhospitable environmental conditions in the Mila Group platform led to a considerable reduction in ichnodiversity, bioturbation intensity and depth and size of burrows, which led to periods of dominating calcimicrobe ecology. The development of exotic or anachronistic facies started around the Cambrian Stage 4–Wuliuan boundary, probably simultaneous with the SPICE event, whereas the Furongian exotic facies period probably took place simultaneous with the HERB event. Biotic and physico-chemical changes in the ocean during these events may have led as well to the virtual absence of the mixed layer and infaunal ecospace utilization in the deposits of the Mila Group. Nevertheless, the local presence of metazoan-microbial build-ups that established between the two suggested exotic facies developments indicates that these periods started at the Cambrian Stage 4–Wuliuan boundary interval, but a fluctuation of abnormal palaeoceanographic conditions and ambient normal marine conditions took place during the Miaolingian and Furongian in the Alborz Basin as a representative of the northern Gondwanan margin.

The Pleistocene coastal eolianite formations in Portugal have provided an unexpected ichnological record of moderate diversity and circumscribed abundance related with mammals and birds, particularly in SW Alentejo. Several large tracks attributed to bear were recently been found in a small inlet at north of Praia do Cavalo, not far from Longueira (Odemira), at Medo Tojeiro/Almograve Eolianite which is tentatively dated from MIS3-2? (about 30,000 years BP). They are organized in two trackways composed of possibly 10 tracks; tracks are not well preserved since they show different undertrack preservational variants, in coarse-grained sandstones. The strong variation of track length, the wide range of footprint length/width ratio, the sole impression of the claws and the non-recognized impression of the heel are possibly related with an animal walking up a steep dune slope; the speed estimation of 2,4 km/h contributes for this interpretation. Most of these large tracks show five-digit dragging prints and the inward rotation of the foot typical from bears. The digit prints are generally packed together which is a characteristic of brown bears. These are the first tracks tentatively attributed to bears in the Portuguese paleontological record and the first ever recorded in eolianite facies.

Species of burrowing animals have changed substantially over evolutionary time scales, but, surprisingly, burrows display persisting morphological patterns throughout the Phanerozoic. Deep-sea burrows are geometrically patterned, whereas shallow-marine burrows display simpler morphologies. This divergence between burrow associations is one of the central conundrums of paleontology, but it has never been quantitatively demonstrated, and the organizing principles responsible for this structure remain unknown. We show that the divergence of burrow associations has been shaped by small-world dynamics, which is proposed as a major macroevolutionary force in marine environments. Using network analysis, our study reveals that the association patterns between burrow morphotypes in 45 paleontological sites span ∼500 m.y. Strong statistical support is demonstrated for a surprising association pattern, according to which the data set is optimally partitioned into two subgroups of tightly associated burrow types. These groups correspond to shallow- and deep-marine biomes. Our analysis demonstrates that across the Phanerozoic Eon, burrows did not assemble randomly nor regularly, following instead small-world assembly rules remarkably similar to those that shape human social networks. As such, small-world dynamics deeply influenced gene flow and natural variation in heritable behavior across evolutionary time.

The formation and development of major rivers limits the overall pace of the surrounding landscape evolution and drives sediment delivery from source to sink. The timings and rates of river incision may be a response to external influences, such as tectonic or climate driven base-level changes, or alternatively they may be linked to the breaching of internal thresholds, for example, drainage capture events. The Tejo and Douro rivers (also known as Tagus and Duero rivers) each drain a significant portion of the Iberian Peninsula and much of their courses through Portugal are typified by v-shaped valleys that are deeply incised into the surrounding topography. Earlier work has dated fluvial terrace deposits, mostly by luminescence techniques, but also by electron spin resonance and cosmogenic nuclide exposure dating. This has provided constraints on the late Pleistocene histories of the Tejo and Douro rivers, however, the timing of their transition from endorheic to exorheic is not precisely known and whether or not their histories are linked to a common mechanism is unclear.This study aims to provide age constraints on the early history of the Tejo and Douro rivers, and to examine whether and to what degree the erosion rates of low relief, granite etchplain landscapes within the river’s catchment areas are responding to the trunk channel incision. We focus on reaches of the Tejo and Douro rivers located in the eastern sector of mainland Portugal. Samples were collected for cosmogenic nuclide (10Be and 26Al) surface exposure and burial dating to date upper fluvial terrace levels. In addition, a combination of cosmogenic nuclide exposure ages and depth profiles in bedrock outcrops, alongside basin-wide erosion rate determinations will be used constrain the pace of evolution of nearby granitic landscapes. Preparation of the samples for measurement is ongoing and we will present our initial findings.

We present a new tracksite with multiple dinosaur tracks from the lowermost Barremian (Lower Cretaceous) of the Cape Espichel (Sesimbra, Portugal). The tracks are localized on three beds on the top carbonate beds of the Areia do Mastro Formation. Those bioclastic, nodular limestones were deposited in a very shallow subtidal-intertidal, restricted lagoon environment. The track surfaces are very dinoturbated, with a substantial number of tracks. Several tracks assign to sauropods, ornithopods and theropods dinosaurs were recorded. Due to heavy bioturbation and the preservation conditions, it is not possible to define trackways; some preliminary work done on the tracks could disclose some behaviours of their producers. Several species of carnivore and herbivore dinosaurs crossed that large area at different times. Herbivores may have used the lagoon margin as passage between feeding spots, while carnivores frequented the area to hunt in groups or individually.

Well-preserved tracks of the wild boar Sus scrofa are described from the Matalascañas Trampled Surface (MTS) in the upper Pleistocene aeolian basal unit of the El Asperillo Cliff, Huelva (southwestern Spain). These are the first published tracks of suid pigs in the fossil record, here formally described as Suidichnus galani igen. and isp. nov. A revision of valid artiodactyl ichnogenera is provided for comparison. The large size of wild boar found in the Late Pleistocene of Spain contradicts the general trend towards smaller size known for the evolution of the species and the Bergmann's ecogeographical rule for the extant subspecies. In the present case, the remarkable large size that can be reached by these tracks is discussed as an ecomorphological adaptation of wild boars to either resource bonanza, and/or predation pressure during the Last Interglacial. The large S. scrofa scrofa identified in MTS corresponds to some of the earliest evidences known to this subspecies in Iberia.

Facies stacking patterns and stratigraphic relationships resulting from the interaction of fluvial and wave processes, along with the paleoshoreline orientation and key surfaces, are essential to understand the temporal changes in the rate of change of accommodation space (A) versus sediment supply rate (S). High-frequency sea-level fluctuations in deltaic systems are controlled by changing accommodation and accumulation, which are explained mainly by autocyclic or allocyclic mechanisms. In deltaic systems, changes in the A/S ratio can be showed by significant variations of the internal facies architecture and the external morphology of the delta complex. These criteria have been used to investigate the relationship between autocyclic and allocyclic processes on the architectural evolution of a mixed river- and wave-influenced asymmetrical delta during the Lower-to-Middle Ordovician in the southwest Central Iberian Zone, in Portugal. Relying on the sedimentary and ichnological characteristics, the herein defined Penha Garcia Formation is classified into two main groups of facies associations, which are interpreted as deposited in a mixed asymmetrical delta with a trend of along-strike variations between wave-dominated strandplain (updrift) and river-dominated deltaic settings (downdrift). The vertical stacking arrangements of parasequences led to the identification of five depositional phases (I to V). Detailed analysis of geometry and internal architecture of the depositional phases along depositional strike shows a highly variable number of shallowing-upward cycles and facies thicknesses/heterogeneity on the updrift and downdrift side due to changes in rates of accumulation and hydrodynamic processes. The stratigraphic architectural style of the depositional phases I to V, and the trend of the total regressive ascending shoreline trajectory, are evidences that the deposition of the Penha Garcia Formation likely took place under an increasing rate of accommodation due to long-term relative sea-level rise (allocyclic), and high subsidence rates coupled with an increase in sediment supply, which could have been locally amplified by compaction of the prodelta-related muddy beds (autocyclic). This study suggests that in evaluating the autocyclic mechanisms on deltaic processes in short-time scales, there is a remarkable difference in terms of its impact on the internal variability of the depositional phases, both in the updrift and downdrift regions of mixed-influenced asymmetrical deltas. The most important reasons for the different effects of autocyclic mechanisms can be related to facies-dependent differential compaction or local changes in subsidence pattern, differences in the proximity to the distributary channel system, and differences in the influence of intrinsic processes of storm and wave reworking (wave-sweeping mechanisms).

The key problems and challenges connected with the Covid-19 pandemic in the field of education in sub-Saharan Africa are described in this paper. The study is based on the information collected from teachers and parents during the lockdown. The main problems connected with the organization of distance learning, such as the availability and accessibility of electricity and stable communications, were described. The main questions connected with the support of e-learning such as unequal access to distance education platforms and tools and readiness of teachers of public and private schools were described. Key social and demographic challenges and threats to sustainable e-learning, such as critical overload of teachers, child mobilization for domestic tasks, age, ethnic and gender-based harassment and violence were analyzed. It was found that the main risks are the rapid and uncontrolled commercialization of education and the decline of public schools, which leads to a decrease in the quality of education and increasing inequality. It was concluded that pandemic-induced risks in education are non-linear and heterogeneously spatially, temporally, and socially distributed. The successful strategy of these risks reduction aimed at sustainable education should be based on transition plans, which must include not only the development of sustainable education but also the fighting against inequality.

In his short joint ventures across the world of vertebrate tracks, Richard Bromley recognized the aeolian sands as unsuitable soft substrates for their preservation. Only after his work in the Bale...

The Cabeço da Ladeira paleontological site in central Portugal became known as the “Jurassic Beach”. Formerly an active quarry, the site was protected in order to preserve the large exposures of a Middle Jurassic (early? Bajocian) carbonate tidal flat with an outstanding fossil record. This multidisciplinary paleontological work involving experts from several national and international research and geoconservation institutions was carried out under the umbrella of the Institute for Nature Conservation (ICNF), since this geosite is located within the Serras de Aire e Candeeiros nature park. Cabeço da Ladeira has provided exquisitely preserved body fossils, especially echinoderms, together with the exceptional preservation of their, and other, animal’s behaviors. It is also a hotspot to understand the diversity of bivalves in the Middle Jurassic. Due to the large area of the geosite, the international relevance of the findings, and the risk of weathering and destruction of the fossils, a geoconservation plan has been developed by ICNF with the support of local authorities. After several years of being open to visitors without proper control, the Cabeço da Ladeira paleontological site is now conditioned to organized groups of researchers, schools, and tourists. Some body fossils were collected for studies and included in the national collections of the Geological Museum (Lisbon). Moreover, casts have been made to protect holotypes of trace fossils, also providing ways to replicate this fossil record in temporary exhibitions. A long-term experimental study to conserve the limestone bedding plane exposures and their fossil contents was started in order to develop the best geoconservation strategy with an aim to reduce the damage produced by the increasing tourist demand on natural sites. Cabeço da Ladeira and other geosites in protected areas are key to communicating an evolutionary approach to environmental education, and their geoconservation must be a priority to improve their long-term use as (geo)tourism attractions. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. The work of AB has been supported by the ALAN‐X, PALEOGIANTS, and CAMBIACLIMA projects (University of Genova, Italy). Fieldwork was partially conducted with the financial support of Naturtejo, E.IM.

Tracks and trackways of newborns, calves and juveniles attributed to straight-tusked elephants were found in the MIS 5 site (Upper Pleistocene) known as the Matalascañas Trampled Surface (MTS) at Huelva, SW Spain. Evidence of a snapshot of social behaviour, especially parental care, can be determined from the concentration of elephant tracks and trackways, and especially from apparently contemporaneous converging trackways, of small juvenile and larger, presumably young adult female tracks. The size frequency of the tracks enabled us to infer body mass and age distribution of the animals that crossed the MTS. Comparisons of the MTS demographic frequency with the morphology of the fore- and hind limbs of extant and fossil proboscideans shed light into the reproductive ecology of the straight-tusked elephant, Palaeloxodon antiquus. The interdune pond habitat appeared to have been an important water and food resource for matriarchal herds of straight-tusked elephants and likely functioned as a reproductive habitat, with only the rare presence of adult and older males in the MTS. The preservation of this track record in across a paleosol surface, although heavily trampled by different animals, including Neanderthals, over a short time frame, permitted an exceptional view into short-term intraspecific trophic interactions occurring in the Last Interglacial coastal habitat. Therefore, it is hypothesized that Neanderthals visited MTS for hunting or scavenging on weakened or dead elephants, and more likely calves. Research was possible thanks to the Delegaciones territoriales de Huelva, Consejería de Agricultura, Ganadería, Pesca y Desarrollo Sostenible and Consejería de Cultura (Junta de Andalucía), Servicio de Geodiversidad y Bio-diversidad (Dirección General de Medio Natural, Biodiversidad y Espacios Protegidos) and The National Park of Doñana. Thanks to Juan Jose Negro for several photos provided and Ramón López Romero during fieldwork. This work has been supported by the Research Groups RNM-293 and RNM-238, University of Huelva & Junta de Andalucía, and by the Fundação para a Ciência e Tecnologia, (with FEDER and COMPETE 2020 funds) under the project UIDB/MAR/04292/2020 (MARE — Marine and Environmental Sciences Centre). CNC would like to thank the financial support from the Câmara Municipal de Odemira. This work also received institutional support from the Naturtejo, E.I.M. (Naturtejo UNESCO Global Geopark). We would like to thank to all the colleagues who have collaborated in the field campaigns. The authors extend their warm appreciation to the Editorial Board member Matteo Belvedere and the reviewers Lara Sciscio and an anonymous that helped to significantly improve the present paper.

Seeking signs of past life in the geological record of Mars is one of the four primary goals of the NASA Mars 2020 mission. However, scant attention has been paid to the fossilized products of life-substrate interactions (ichnofossils), which are one of the most abundant and reliable biosignatures on Earth. This lack of attention is surprising because the ichnofossil heritage does not include only metazoan tracks, but also macroscopic burrows produced by bacteria, microborings ascribed to the activity of bacteria and fungi, and biostratification structures produced by archaea, cyanobacteria and euglenozoans. In light of this gap, the goal of the present study is evaluating the suitability of the Mars 2020 Landing Site for ichnofossils. To this goal, this work applies palaeontological predictive modelling, a technique used to predict the location of fossil sites in uninvestigated areas on Earth. Accordingly, a GIS of the landing site is developed. Each layer of the GIS maps the suitability for one or more ichnofossil types (bioturbation, bioerosion, biostratification structure) based on an assessment of a single attribute (suitability factor) of the Martian environment. Suitability criteria have been selected among the environmental attributes that control ichnofossil abundance, preservation, and accessibility in W Liguria (Italy), Naturtejo UNESCO Geopark (Portugal), and Ômnôgov district (Mongolia). The goal of this research will be delivered through a predictive map showing which areas of the Mars 2020 landing site are more likely to preserve ichnofossils. This map can be used to guide future efforts to the regions of the Mars 2020 Landing Site with the highest ichnological potential, realizing benefits in life-search efficiency and cost‐reduction.

The behaviour of the iconic ichnogenus Chondrites is re-evaluated based on review of existing literature and analysis of novel data (macroscopic, thin section and ESEM-EDX observations; CT-scans and resin peels of modern analogues; computer-controlled serial grinding; morphometric analysis and theoretical morphology). The bedding plane expression of Chondrites is well-constrained by morphometry: (1) the angle of dichotomy formed by a pair of adjacent branches is typically between 30° and 56° (interquartile range; mean: 47°); (2) branching order is between 1 and 9; (3) branches are, on average, nine times longer than wide. In the third dimension, downward branching is dominant but bundled shafts and upward branching may be present. The size of Chondrites increased markedly from the Late Jurassic to the Late Cretaceous, suggesting that the tracemakers became larger and larger. Microfabric analysis of Chondrites shows active fill or, alternatively, passive fill of empty tunnels by currents or clay percolation, a new mechanism proposed herein. The tracemakers built Chondrites to obtain food: (1) vermiform deposit feeders produced Chondrites for searching for food in the sediment (fodinichnion); (2) asymbiotic bivalves built Chondrites for cultivating and directly ingesting bacteria (agrichnion); (3) chemosymbiotic bivalves produced Chondrites to provide symbionts with chemical agents. Chondrites was modified through the life of the tracemaker or it represented a part of the producer’s lifespan. Chondrites — and its modern tracemaker(s) — is associated with a range of marine settings, including well-oxygenated, dysoxic and space-limited (nucleocave) environments. As such, Chondrites is regarded as an extremotolerant ichnotaxon.

The paleoenvironment of the type section of the Destacamento Rio Salado Member, (Canal de las Escobas Formation, Middle Holocene, northeastern Buenos Aires province, Argentina) is described from sedimentological and paleontological points of view. Two lithofacies association were recognized: muddy lithofacies association includes lenticular, planar lamination and homogeneous sedimentary structures, and represents subaqueous decantation of clay in intertidal-subtidal depositional environments; the heterolithic lithofacies association includes wavy, hummocky, flaser, and cross-lamination lithofacies, suggesting periodic increases of fine sand input in an environment with variable tidal energy. Paleontological content includes: Ophiomorpha nodosa, Thalassinoides suevicus and Maiakarichnus isp., dominate in ichnofauna along the stratigraphic column; Oblongichnus isp. is produced by the infaunal bivalve Solen tehuelchus, confirming a shallow littoral environment. Molluskan shell concentrations includes parautochthonous-allochthonous components in beds, lenses, pouches and pods and suggesting variation in water energy; borings in carbonate fragments and bioclasts indicates that they were exposed to the surface prior to final burial. A complete fur seal skeleton indicates that it was rapidly buried after death, indicating the presence of sedimentation rhythmicity. Micropaleontological evidence confirms the interpretation based on lithofacies analyses. The integrated analysis of the sedimentological and faunal composition suggest marine dominant provenance with minor fluvial components.

Molecular species identification plays a crucial role in archaeology and palaeontology, especially when diagnostic morphological characters are unavailable. Molecular markers have been used in forensic science to trace the geographic origin of wildlife products, such as ivory. So far, only a few studies have applied genetic methods to both identify the species and circumscribe the provenance of historic wildlife trade material. Here, by combining ancient DNA methods and genome skimming on a historical elephantid tooth found in southwestern Portugal, we aimed to identify its species, infer its placement in the elephantid phylogenetic tree, and triangulate its geographic origin. According to our results the specimen dates back to the eighteenth century CE and belongs to a female African forest elephant (non-hybrid Loxodonta cyclotis individual) geographically originated from west—west-central Africa, from areas where one of the four major mitochondrial clades of L. cyclotis is distributed. Historical evidence supports our inference, pointing out that the tooth should be considered as post-Medieval raw ivory trade material between West Africa and Portugal. Our study provides a comprehensive approach to study historical products and artefacts using archaeogenetics and contributes towards enlightening cultural and biological historical aspects of ivory trade in western Europe.

The geoheritage value of sedimentary building stones has mainly focused on physical sedimentary structures and body fossils. By contrast, little attention has been placed on the geoheritage significance of ichnofabrics, which are the sedimentary fabrics that have been reworked by organisms. This study aims to fill this gap by analysing the ichnofabric found on the buildings of Piazza della Vittoria, in Genova (Italy). Here, unusually visible and well-preserved specimens of the fossil burrow Bichordites are observed on the historical buildings designed by Marcello Piacentini, one of the local most prominent architects of the 1930s. The Bichordites of Piazza della Vittoria are winding meniscate burrows with a central string-like structure. Here, we interpret this ichnofabric as the result of the activity of a community of echinoids bioturbating a sand wave system. We have also located the historical quarry that provided material for the studied buildings with the same ichnofossils exposed. Surprisingly, the cuts on display on the buildings are much nicer than those in the outcrops and more taxon specific characteristics can be observed just on the tiles rather than in the field. For all these reasons, the geoheritage value of the Piazza della Vittoria ichnofabric relies in its unique scientific significance, the cultural value, and its potential future applications in research, teaching, urban geotourism and reference site.

This study analyzes in detail the beds bearing Rhizocorallium in the Upper Triassic Nayband Formation (Tabas Block, Central Iran) and shows their potential in interpreting depositional settings, ecological features and sequence stratigraphy. An integrated approach combining ichnological, sedimentological and stratigraphic methods has significantly enhanced our understanding of the changes in the spatial distribution style and morphological differences among the same ichnospecies of Rhizocorallium. The Upper Triassic Rhizocorallium assemblages from the Nayband Formation reveal significant spatial variations in the orientation and dimensions (i.e., length, width, limb diameter), the tiering pattern, and the colonization style throughout systems tracts and at erosional discontinuities or omission surfaces. Based on the wide variety of forms and orientation, numerous morphotypes of Rhizocorallium are grouped into two main types, i.e., those that are mostly facies controlled and those that appear abundantly in a confined stratigraphic interval and are facies independent. In this respect, three paleoichnocoenoses or habitats for the rhizocorallid producers could be differentiated according to the burrow morphology and the nature and consistency of the substrate: (1) stable habitat, represented by soft substrates including horizontal, long, straight or slightly sinuous, spreite-bearing, U-shaped protrusive burrows of Rhizocorallium irregulare (= R. commune var. irregulare). This habitat resulted from processes operating in settings that are characterized by soft substrates, reduced sedimentation rates, and abundant food supply, typical of low- to moderate-energy, fully marine conditions; (2) unstable, physically-controlled habitat, represented by a suite of shifting substrates with low- to high-energy settings, including short, U-shaped protrusive spreiten-burrows of R. jenense (Type 1). In this habitat alternating and contrasting energy conditions did exist due to repeated storm events that were the main controlling factor in the distribution and preservation of Rhizocorallium; (3) substrate-controlled habitat represented by a suite of stiff-to-firm substrates including oblique to vertical protrusive or retrusive spreiten U-shaped burrows of R. jenense (Type 2). The erosional discontinuities or omission surfaces related to this habitat include parasequence-bounding transgressive surfaces of erosion (TSE) and parasequence-bounding flooding surfaces (FS) and are mainly associated with the Rhizocorallium-dominated Glossifungites ichnofacies. Complementary ichnological information indicates that the shift in the orientation and the morphological features of rhizocorallid burrows point to broad changes of environmental parameters, which are, in turn, controlled by the rate of sea-level changes.

Ichnofossils, the fossilized products of life-substrate interactions, are among the most abundant biosignatures on Earth and therefore they may provide scientific evidence of potential life that may have existed on Mars. Ichnofossils offer unique advantages in the search for extraterrestrial life, including the fact that they are resilient to processes that obliterate other evidence for past life, such as body fossils, as well as chemical and isotopic biosignatures. The goal of this paper is evaluating the suitability of the Mars 2020 Landing Site for ichnofossils. To this goal, we apply palaeontological predictive modelling, a technique used to forecast the location of fossil sites in uninvestigated areas on Earth. Accordingly, a geographic information system (GIS) of the landing site is developed. Each layer of the GIS maps the suitability for one or more ichnofossil types (bioturbation, bioerosion, biostratification structures) based on an assessment of a single attribute (suitability factor) of the Martian environment. Suitability criteria have been selected among the environmental attributes that control ichnofossil abundance and preservation in 18 reference sites on Earth. The goal of this research is delivered through three predictive maps showing which areas of the Mars 2020 Landing Site are more likely to preserve potential ichnofossils. On the basis of these maps, an ichnological strategy for the Perseverance rover is identified, indicating (1) 10 sites on Mars with high suitability for bioturbation, bioerosion and biostratification ichnofossils, (2) the ichnofossil types, if any, that are more likely to be present at each site, (3) the most efficient observation strategy for detecting eventual ichnofossils. The predictive maps and the ichnological strategy can be easily integrated in the existing plans for the exploration of the Jezero crater, realizing benefits in life-search efficiency and cost-reduction.

El presente estudio se centra en las icnocenosis de Zoophycos que se encuentran en superficies de omisión a lo largo del estratotipo de la unidad “Margas e calcários detríticos com Zoophycos da Praia da Mareta”, de edad Bajociense superior-Bathoniense inferior. La forma de los Zoophycos compuestos de la Praia da Mareta se puede explicar por un multi-spreite helicoidal con espiral logarítmica, constituido por láminas de galerías en U, del tipo Rhizocorallium, desarrolladas oblicuamente y de modo centrípeto a partir de un eje de enrollamiento. En los niveles estudiados, los productores de Zoophycos aparecen en grandes densidades y no muestran características bióticas o ambientales de icnocenosis oportunistas. Integrando los datos obtenidos en este trabajo para Zoophycos, en un contexto estratigráfico nacional o incluso global, se pueden visualizar los factores ecológicos que han permitido la evolución temporal de la icnofacies de Zoophycos. La elaboración de diagramas cronológico-ambientales a partir de los datos conocidos sobre los Zoophycos de Portugal y de más de un centenar de referencias bibliográficas de todo el mundo, ha permitido verificar que en Portugal existe la misma tendencia de radiación ecológica hacia una colonización de áreas profundas, difiriendo en algunos aspectos de los datos obtenidos anteriormente por otros autores. De hecho, los Zoophycos son colonizadores pioneros, pero fortuitos, de los fondos marinos (Ordovícico Inferior), restringiéndose exclusivamente a los nichos batiales-abisales después de la gran extinción de finales del Cretácico.

O icnogénero Arthrophycus Hall, 1852 presente no Arenigiano-Oretaniano da Formação do Quartzito Armoricano (Portugal) é revisto com base em novos dados e na re-avaliação das colecções de Nery Delgado, sendo descritas duas icnoespécies, A. alleghaniensis (Harlan, 1831) e A. linearis Seilacher, 2000, com as variantes morfoetológicas A. alleghaniensis lateralis e A. linearis tipo protrusiva. Os resultados alcançados para Portugal entram em conflito, do ponto de vista estratigráfico, icnotaxonómico e comportamental repercutindo-se na interpretação dos seus possíveis produtores, com os dados obtidos por Seilacher (2000), aconselhando alguma precaução na aplicabilidade icnostratigráfica de Arthrophycus.

The palaeoenvironmental significance of trace fossil assemblages in the shallow marine deposits of the Late Triassic Nayband Formation of the Tabas Block, Central Iran has been assessed for the first time. The siliciclastic successions of the Nayband Formation, are highly bioturbated and allow relationships between changes in ichnoassemblages within a depositional system to be documented and placed in a palaeoenvironmental framework. The main purposes of this paper are: (1) to describe and illustrate the trace fossils assemblages of the Nayband Formation; (2) integration of ichnologic and sedimentologic data to evaluate different stress factors on the infaunal communities; and (3) to briefly discuss paleoenvironmental distribution of various trace fossil assemblages in order to differentiate between deltaic and non-deltaic shoreface successions. The Upper Triassic Nayband Formation has been studied and measured in one section, where the Nayband Formation is well accessible and continuously exposed. This section was logged and evaluated using physical sedimentology and ichnology in order to establish a basis for the interpretation of sedimentary processes (facies) and depositional systems. In this study, trace fossils (diversity, abundances, and ethologies) and the spatial arrangement of sedimentary structures are used to further refining the interpretation of environmental parameters such as hydrodynamic energy, water turbidity, substrate properties, food supply, temperature, oxygenation, salinity, and sedimentation rates. Based on facies characteristics and stratal geometries, the siliciclastic succession is divided into two facies associations, fluvial-dominated delta (FA), and open marine (FB). Twenty-eight ichnogenera have been identified in delta and open marine successions: The assemblage is dominated by Rhizocorallium, Thalassinoides, Ophiomorpha, Helminthopsis, Palaeophycus and Skolithos. Their distribution is clearly linked with lithofacies and depositional environments. High rates of fluvial discharge, high water turbidity, seasonally high rates of deposition and phytodetrital pulses in river-dominated deltas may cause marked variations in the temperature, oxygenation and salinity of the fluvial-dominated delta successions. All of these factors in combination lead to impoverishment in trace diversity and reduction in burrow size but to rapid colonization of the substrate by single-layer colonizers of opportunistic deposit feeders. Low ichnodiversity, low bioturbation intensities with highly bioturbated clusters shown by single colonization events by opportunistic, simple feeding strategies of trophic generalists and a paucity of suspension-feeding structures elements represent a “stressed”, non-archetypal Cruziana ichnofacies. The changes of behavioural complexity and the tiering profiles in the offshore-shoreface complex of the Nayband Formation when compared with the river-dominated delta successions represent the transition from epifaunal life habits with simple tiering structures to infaunal life habits with complex tiering pattern. The occurrence of diverse trace fossil suites attributable to the Zoophycos ichnofacies, the archetypal Cruziana ichnofacies and the Skolithos ichnofacies in wave-dominated shoreface-offshore complex point to stress-free environmental conditions in open waters due to persistent wave agitation, and hence, a wide colonization window.

New images from Mars rover Curiosity display millimetric, elongate stick- like structures in the fluvio-lacustrine deposits of Vera Rubin Ridge, the depositional environment of which has been previously acknowledged as habitable. Morphology, size and topology of the structures are yet incompletely known and their biogenicity remains untested. Here we provide the first quantitative description of the Vera Rubin Ridge structures, showing that ichnofossils, i.e., the product of life-substrate interactions, are among their closest morphological analogues. Crystal growth and sedimentary cracking are plausible non-biological genetic processes for the structures, although crystals, desiccation and syneresis cracks do not typically present all the morphological and topological features of the Vera Rubin Ridge structures. Morphological analogy does not necessarily imply biogenicity but, given that none of the available observations falsifies the ichnofossil hypothesis, Vera Rubin Ridge and its sedimentary features are here recognized as a privileged target for astrobiological research.

The Meridional Meseta Naturtejo Geopark was the doorway for the development of several geoparks in Portugal seeking to become part of a formal UNESCO initiative under the Global Geoparks Network. The outstanding geological heritage summing 176 geosites is part of an ancient etchplain-type landscape where residual reliefs and deeply incised rivers, including the Tejo (Tagus), coexist with Variscan and Alpine orogenies-related tectonic landforms, between the Southern Plateau and the Iberian Central Mountain Belt. Local identity is strongly bonded to geological landscapes, a relation that is being used to promote the territory as a new and different nature tourism destination in the domestic and foreign markets, and to foster projects for local sustainable development. The approach of the Naturtejo Global Geopark is to promote networking within the territory in both public and private sectors and with other geological-related institutions and geoparks in subjects such as heritage protection and use, formal and non-formal education and sustainable economy based on local resources.

The Middle–Late Ordovician Ghelli Formation in the Kopet Dagh region northeastern Alborz range of Iran is composed of siliciclastic rocks deposited in a variety of turbidite to marginal marine environments (deep marine clastic fan and related environments and prodelta, distal delta front, proximal delta front and distributary channels). The ichnology of the middle member of the Ghelli Formation is here reported. Combined sedimentological and ichnological analysis allows recognition of a tide-influenced deltaic succession in the middle member of the Ghelli Formation consisting of three main facies associations: lower distributary channels, delta front and prodelta facies. Twenty-two ichnogenera have been identified in this marginal marine succession: Arenicolites, Arthrophycus, Bergaueria, Chondrites, Conichnus, Cruziana, Cylindrichnus, Didymaulichnus, Diplichnites, Diplocraterion, Helminthopsis, Gyrochorte, Lockeia, Macaronichnus, Monomorphichnus, Palaeophycus, Planolites, Rosselia, Rusophcus, Skolithos, Teichichnus and ?Scolicia. Their distribution is clearly linked with lithofacies and depositional palaeoenvironments. The ichnological analysis reveals that the trace fossil suites developed in these environments indicate low diversity and low to moderate abundance of burrows, poor development of tiering and sporadic distribution. Low ichnodiversity and low bioturbation intensities with higher bioturbation clusters consist of facies-crossing ichnogenera, and the impoverishment of suspension-feeding trophic types indicates ‘stressed’, non-archetypal expression of the Cruziana ichnofacies. The periodic higher intensities of bioturbation due to variations in hydrodynamic regimes of tidal currents reflect the archetypal of the Cruziana ichnofacies (and rare Skolithos ichnofacies).

Trace fossils are important evidence of benthic activity, but they have received less study than body fossils for investigating the aftermath of the end-Permian extinction. There is therefore a need to document Lower Triassic ichnofaunas to understand their significance with respect to the end-Permian crisis. In light of this need, this paper describes a novel Lower Triassic ichnosite at Mount Pallone (Carnic Alps, Italy), where the Campil Member (Smithian) of the Werfen Formation (Griesbachian–Spathian) presents an abundant ichnofauna characterized by excellent preservation and low diversity. Documented ichnogenera include Asteriacites lumbricalis, Gyrochorte comosa, Diplocraterion habichi and Planolites beverleyensis. The ichnofaunal composition and the bioturbation style suggest a marginal marine paleoenvironment ranging from intertidal to shallow subtidal settings. Storm influence, hydrodynamic energy, sedimentation rate, freshwater input and/or water temperature played an important role in structuring the benthic ecosystem. Dense (300 specimens/m2) aggregations of the trace fossil Asteriacites lumbricalis reveals social behavior of their inferred brittlestar producers (Echinodermata, Ophiuroidea). In line with modern brittlestar beds, social behavior provided significant advantage because raised arms of brittlestars dampened hydrodynamic energy. This study suggests that Asteriacites beds may be considered ichnological proxies for marine settings, low bioturbation intensity, shallow tiering, high sedimentation rate and/or event-bed deposition, significant levels of hydrodynamic energy, and low predation pressure. The studied ichnofauna reflects stressed environmental conditions, but it is unclear whether this reflects local brackish conditions (‘Gazpacho model’) or global hot temperatures (‘Hot Soup model’).