Biodiversity of ecosystems in an arid setting: The late Albian plant communities and associated biota from eastern Iberia

Deserts are stressful environments where the living beings must acquire different strategies to survive due to the water stress conditions. From the late Albian to the early Cenomanian, the northern and eastern parts of Iberia were the location of the desert system represented by deposits assigned to the Utrillas Group, which bear abundant amber with numerous bioinclusions, including diverse arthropods and vertebrate remains. In the Maestrazgo Basin (E Spain), the late Albian to early Cenomanian sedimentary succession represents the most distal part of the desert system (fore-erg) that was characterised by an alternation of aeolian and shallow marine sedimentary environments in the proximity of the Western Tethys palaeo-coast, with rare to frequent dinoflagellate cysts. The terrestrial ecosystems from this area were biodiverse, and comprised plant communities whose fossils are associated with sedimentological indicators of aridity. The palynoflora dominated by wind-transported conifer pollen is interpreted to reflect various types of xerophytic woodlands from the hinterlands and the coastal settings. Therefore, fern and angiosperm communities abundantly grew in wet interdunes and coastal wetlands (temporary to semi-permanent freshwater/salt marshes and water bodies). In addition, the occurrence of low-diversity megafloral assemblages reflects the existence of coastal salt-influenced settings. The palaeobotanical study carried out in this paper which is an integrative work on palynology and palaeobotany, does not only allow the reconstruction of the vegetation that developed in the mid-Cretaceous fore-erg from the eastern Iberia, in addition, provides new biostratigraphic and palaeogeographic data considering the context of angiosperm radiation as well as the biota inferred in the amber-bearing outcrops of San Just, Arroyo de la Pascueta and La Hoya (within Cortes de Arenoso succesion). Importantly, the studied assemblages include Afropollis, Dichastopollenites, Cretacaeiporites together with pollen produced by Ephedraceae (known for its tolerance to arid conditions). The presence of these pollen grains, typical for northern Gondwana, associates the Iberian ecosystems with those characterising the mentioned region.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEMinisterio de Ciencia, Innovacio ́n y UniversidadesIGME-CSICSecretaria d’Universitats i Recerca de la Generalitat de CataloniaEuropean Social Fundpu

Amber and the Cretaceous Resinous Interval

Amber is fossilized resin that preserves biological remains in exceptional detail, study of which has revolutionized understanding of past terrestrial organisms and habitats from the Early Cretaceous to the present day. Cretaceous amber outcrops are more abundant in the Northern Hemisphere and during an interval of about 54 million years, from the Barremian to the Campanian. The extensive resin production that generated this remarkable amber record may be attributed to the biology of coniferous resin producers, the growth of resiniferous forests in proximity to transitional sedimentary environments, and the dynamics of climate during the Cretaceous. Here we discuss the set of interrelated abiotic and biotic factors potentially involved in resin production during that time. We name this period of mass resin production by conifers during the late Mesozoic, fundamental as an archive of terrestrial life, the `Cretaceous Resinous Interval (CREI).This work was supported by the Spanish Ministerio de Ciencia, Innovación y Universidades [research agreement CRE CGL2017-84419 AEI/FEDER, UE] and by the Consejería de Industria, Turismo, Innovación, Transporte y Comercio of the Gobierno de Cantabria through the public enterprise EL SOPLAO S.L. [research agreement #20963 with University of Barcelona and research contract Ref. VAPC 20225428 to CN-IGME CSIC, both 2022–2025]; the Conselho Nacional de Pesquisa (Brazil) [research grand PQ 304529/19–2]; National Geographic Global Exploration Fund Northern Europa [research agreement GEFNE 127-14]; Deutsche Forschungsgemeinschaft (DFG) [research agreement SO 894/6-1]; VolkswagenStiftung [research agreement 90946]; the Secretary of Universities and Research (Government of Catalonia) and by the Horizon 2020 program of research and innovation of the European Union under the Marie-Curie [research contract no. 801370, Beatriu de Pinós]; the Secretary of Universities and Research (Government of Catalonia) and the European Social Fund [research contract 2021FI_B2 00003]; this work is a contribution to the grant RYC2021-032907-I, funded by the MCIN/AEI/10.13039/501100011033 and by the European Union «NextGenerationEU»/PRTR; and the National Agency for Research and Development (ANID) Scholarship Program [BECAS CHILE 2020-Folio 72210321].Abstract Keywords 1. Introduction 2. Definition of the Cretaceous Resinous Interval 3. Conditional factors on resin production and preservation 3.1. Abiotic factors 3.1.1. Atmospheric gas composition, temperature, and wildfires 3.1.2. Volcanism and changes in sea level 3.1.3. Oceanic physicochemical properties and hurricanes 3.1.4. Climatic overview throughout the CREI 3.2. Biotic factors 4. Present limitations and future directions 5. Conclusions Funding Author contributions Declaration of Competing Interest Acknowledgements Appendix A. Supplementary data Data availability Reference

Dinosaur bonebed amber from an original swamp forest soil

Dinosaur bonebeds with amber content, yet scarce, offer a superior wealth and quality of data on ancient terrestrial ecosystems. However, the preserved palaeodiversity and/or taphonomic characteristics of these exceptional localities had hitherto limited their palaeobiological potential. Here, we describe the amber from the Lower Cretaceous dinosaur bonebed of Ariño (Teruel, Spain) using a multidisciplinary approach. Amber is found in both a root layer with amber strictly in situ and a litter layer mainly composed of aerial pieces unusually rich in bioinclusions, encompassing 11 insect orders, arachnids, and a few plant and vertebrate remains, including a feather. Additional palaeontological data—charophytes, palynomorphs, ostracods— are provided. Ariño arguably represents the most prolific and palaeobiologically diverse locality in which fossiliferous amber and a dinosaur bonebed have been found in association, and the only one known where the vast majority of the palaeontological assemblage suffered no or low-grade pre-burial transport. This has unlocked unprecedentedly complete and reliable palaeoecological data out of two complementary windows of preservation—the bonebed and the amber—from the same site.European Regional Development Fund (FEDER)Ministerio de Ciencia e Innovación (MICINN)/FEDERMinisterio de Economía y Competitividad (MINECO)/FEDERGeneralitat de CatalunyaGeneralitat de Catalunya/FEDERMMinisterio de Ciencia e Innovación (MICINN)Oxford UniversityAustrian Academy of SciencesUniversité de TunisGeneralitat ValencianaDepto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Desarrollo de dunas eólicas en un sistema de braidplainárido costero de edad Albienseen la Serranía de Cuenca (Cuenca Ibérica, España)

The Utrillas Sandstone Group is an Albian to Cenomanian clasticsuccession which is widely spread along most areas in the Iberian Basin. Inthe Southwestern sector (Serranía de Cuenca) an arid braidplain wasdeveloped and connected to the Tethys towards SE, thus some faciesassociations present tidal features. Aeolian dune development within thearid braidplain system was possible, although as a minor feature. This paperaims: 1) to describe the facies associations of the arid braidplain regardingtheir different origin, and 2) to study and interpret aeolian duneaccumulations based on the granulometric study of 5 samples and on theoutcrop study of the geometry and surfaces hierarchyEl Grupo Utrillas es una sucesión clástica Albiense-Cenomaniense la cualse encuentra ampliamente extendida en todo el contexto de la Cuenca Ibérica.En el sector Suroccidental (Serranía de Cuenca) un sistema de braidplain áridofue el principal paleoambiente. Este sistema de braidplain árido estuvo conec-tado con el Tethys hacia el SE. El desarrollo de dunas eólicas en el sistema debraidplain fue posible aunque no son una facies muy abundante. Este artículotiene como objetivo: 1) describir las asociaciones de facies del sistema braidedárido, y 2) estudiar e interpretar las dunas eólicas sobre la base del analisis gra-nulométrico de 5 muestras y del estudio de la arquitectura estratigráfica delafloramient

Along-strike sedimentological variability and architectural patterns of the transgression of a “mid”-Cretaceous braidplain system (Iberian Basin, eastern Spain): A tool for depicting eustatic and tectonic signatures within the framework of a global transgression

The mid-Albian to lower Cenomanian Utrillas Group is interpreted as an arid braidplain system in the Serranía de Cuenca region (Iberian Basin, Spain). In its proximal locations, it consists of an interaction of alluvial facies and subordinate aeolian deposits, with the occurrence of tidally-influenced deposits that reflect a general transgressive trend to the top of the succession. However, the distal areas of this braidplain system, where there was a more intense interaction with the Tethys Ocean, have remained understudied to date. We present a sedimentological study of two outcrops (Pajaroncillo and Reíllo) located at the distal sector of the braidplain system and 12 km apart, defining an along-strike relative position. Both outcrops differ notably regarding the arrangement and distribution of the facies associations identified despite their relative closeness. Based on the sedimentological analysis, the main transgressive and regressive trends of the succession have been identified, along with several correlatable stratigraphic surfaces. This has permitted us to distinguish five stages (T1–T5), which reflect the overall transgressive evolution of the succession: a continental aggradational stage (T1), dominated by alluvial deposition; an initial transgression stage (T2) dominated by an open coast setting in Reíllo and a restricted mudflat system in Pajaroncillo; a regressive stage (T3), during which continental alluvial to supratidal environments deposited; a resumption in transgression (T4), characterised by an array of inter- to subtidal environments; and a deepening stage (T5), when the transgression advanced landward, giving rise to the most distal deposits of the studied succession. The studied outcrops, located at the basin edge, have been integrated within the regional sequence stratigraphy framework, which was originally devised for more central areas of the Iberian Basin (Valencia Domain) and the Prebetic. This regional approach has allowed us to interpret the studied deposits as third-order depositional sequences. Besides, the supra-regional implications of this research are discussed within the broader context of Iberia and the subtleties of its tectono-sedimentary evolution during the Albian to Cenomanian times

Palynostratigraphy and palaeoenvironmental evolution of the Aptian to lower Cenomanian succession in the Serranía de Cuenca (Eastern Spain)

The Aptian to lower Cenomanian succession from the Serranía de Cuenca region (Eastern Iberia, Spain) comprises a time-span largely understudied regarding palynology and biostratigraphy. This research studies the deposits of three stratigraphic units that crop out in this region (the Contreras Formation, the El Burgal Member and the Utrillas Group), allowing identification, study and sampling of the palynofloras from the Aptian–?early Cenomanian time-interval. The studied sections are grouped into three sectors based on the palynostratigraphic ages obtained: the MPB, TU, and CT sectors, respectively. The palynoflora is dominated by gymnosperm pollen grains and diversified spores of ferns and allies. The palynofloral evidence and regional geology indicate that the sampled levels in the MPB sector are Aptian in age, whereas those levels sampled at the TU and CT sectors are dated as middle Albian–?early Cenomanian. The Aptian palynofloras of this sector differ from other contemporaneous sites of Europe and North America in the possible occurrence of tricolpate angiosperm pollen. In general, angiosperm pollen does not present high percentages; however, it becomes more diversified from the middle Albian in the TU and CT sectors, where more than 20 taxa were recorded on average. The studied pollen assemblages conform with the characteristics of the early Cenophytic palynofloras. Likewise, an increase in dinocysts towards the upper levels of the sedimentary succession in the TU and CT sectors is consistent with the transgressive nature of the deposits, documenting the progressive landward expansion of Western Tethys in Iberia during Albian to ?early Cenomanian times

Mid-Albian to earliest Cenomanian climate cycles indicated by humid paleosols developed within the arid braidplain facies of the Utrillas Group of east-central Spain

The development of arid climate conditions in eastern Iberia during the mid-Cretaceous (mid-Albian to earliest Cenomanian) has been postulated by several authors over the last two decades based on sedimentological and palaeobotanical datasets. In this paper, we present a combined sedimentological and paleosol study of the mid-Albian to earliest Cenomanian Utrillas Group in the Cuenca Basin of east-central Spain, to improve knowledge of palaeoclimate. Four facies associations are identified as follows: Proximal alluvial braidplain (FA I), Distal alluvial braidplain (FA II), Aeolian dunes (FA III), and Inner estuarine settings (FA IV). The succession records the development of a braidplain system under dominantly arid conditions followed by a marine transgressive phase. In contrast to the overall arid palaeoclimate interpretation, multi-proxy palaeoedaphological analyses conducted for three paleosol profiles (Spodosols) indicate the occurrence of periods of increased humidity in the basin. These findings allow us to infer the occurrence of shorter-term climatic oscillations characterised by a tropical savanna climate when the palaeosols developed, suggesting significantly more humid conditions than those inferred based on the sedimentological and previous palaeobotanical datasets. We propose a palaeoclimatic model that explains the alternation between the dominantly arid and these more humid periods based on the cyclical latitudinal shifting of the mid-Cretaceous climatic belts, shedding new light on the mid-Albian to earliest Cenomanian climate of Iberia.Agencia Estatal de InvestigaciónUnión EuropeaDepto. de Geodinámica, Estratigrafía y PaleontologíaDepto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field