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<jats:title>Abstract</jats:title> <jats:p>The Umbria-Marche Basin of central Italy includes some of the most studied, continuous and well-exposed sequences of Cretaceous pelagic sediments known from the Tethyan Realm. A complete and well-preserved Cretaceous pelagic composite succession (CPCS) of this area is here presented. It has been constructed through the integration of the well-established magnetostratigraphy with the planktonic foraminiferal biostratigraphy based on previous and newly identified events from six key sections and one drill core. The recovery of planktonic foraminifera successfully disaggregated from the hard lithologies allows the identification and precise placement of several primary and secondary bioevents. In particular, the record of the identified bioevents counts thirty-five primary biohorizons, which allow the subdivision of the studied succession into thirty-four zones and four subzones. Following this study and previous findings on Cretaceous planktonic foraminifera, an updated planktonic foraminiferal zonation for the Cretaceous Period is proposed. This refined magnetobiostratigraphic framework, which in this study is integrated with the Cretaceous inoceramid, anoxic, and carbon-isotope events recognized in the Umbria-Marche Basin, may provide an invaluable tool for improving Cretaceous correlations at low to middle latitudes, as well as palaeoenvironmental, palaeoclimatic and palaeoceanographic interpretations.</jats:p>

<jats:title>Abstract</jats:title> <jats:p> The break-up of Gondwana in the latest Jurassic and earliest Cretaceous and the subsequent opening and evolution of the South Atlantic Ocean as a new widening seaway linking northern and southern high latitudes, was the single most significant palaeoceanographic event during the Cretaceous with global consequences for the climate and the biotic evolution, both on land and at sea. Its main evolutionary stages are now becoming well known but, despite that, their global impact has been widely underestimated. Aiming to shed light on some of these unanswered questions, this work presents an overview of research carried out during the past decades in the Sergipe Basin in northeastern Brazil, integrating foraminiferal and ammonite biostratigraphic data, coupled with an assessment of their biogeographic patterns. Three main topics are discussed, the key findings presented and set against their possible global impact: the opening of the Equatorial Atlantic Gateway in the late early to mid-Aptian ( <jats:italic>c.</jats:italic> 118–119 Ma), the mid-Cretaceous dysoxic-anoxic events recorded in the northern South Atlantic (maxima in the late Aptian-earliest Albian, early Cenomanian, and at the Cenomanian-Turonian boundary), and the timing of the North Atlantic-South Atlantic oceanic connection in the late Coniacian to early Santonian ( <jats:italic>c.</jats:italic> 85–87 Ma). </jats:p> <jats:p content-type="supplementary-material"> Supplementary material at <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" specific-use="dataset is-supplemented-by" xlink:href="https://doi.org/10.6084/m9.figshare.c.7016334">https://doi.org/10.6084/m9.figshare.c.7016334</jats:ext-link> </jats:p>

<jats:title>Abstract</jats:title> <jats:p> The plant fossil record during the Cretaceous documents a major transition in the dominant group of terrestrial autotrophs, as plant communities from the earlier Mesozoic were transformed by the appearance and rapid diversification of angiosperms. This transformation began in the Early Cretaceous, continued through the Late Cretaceous and led ultimately to the dominance of angiosperms in most terrestrial ecosystems today, which had profound consequences for the other organisms inhabiting terrestrial ecosystems and perhaps the planet as a whole. Our understanding of angiosperm diversification has been greatly improved over the past 50 years by integrated studies of fossil assemblages containing angiosperm pollen and leaves, but especially by new information from mesofossil floras that have provided previously unanticipated detail on floral form in Cretaceous angiosperms and have allowed the recognition of key dispersed pollen types <jats:italic>in situ</jats:italic> . Information from fossil flowers has greatly facilitated meaningful comparisons with living plants and integration with phylogenetic analyses of extant angiosperms based on DNA evidence. The combined insights from these discoveries provide a broadly consistent and coherent picture of angiosperm evolution through the Cretaceous, which comprises more than half of their entire evolutionary history. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>The Cretaceous marine sediments of Morocco and adjacent coastal basins provide an outstanding archive of environmental diversity from extended shelf seas and marginal basins along the Atlantic and Tethyan margins to deep oceanic basins of the western Tethys and eastern Atlantic Ocean. The geological highlights of Morocco's fascinating landscape include records of Lower Cretaceous Tethyan marginal and deep water clastic sequences in the Rif mountain chain (submarine fan systems of the Massylian and Mauretanian flysch units), as well as siliciclastic sedimentary sequences in subsiding coastal basins (TanTan Delta), which extend offshore along the Northwest African Atlantic margin. Vestiges of the Aptian to Turonian greenhouse climate, sea-level highstands and oceanic anoxic events are exceptionally well-preserved in Tethyan marginal and deep water sedimentary successions of the Rif, in Atlantic coastal basins and as transgressive pulses on the Moroccan Meseta, Sahara platform and High Atlas rift system. Furthermore, sedimentary expressions of the tectonic movements between the African and European plates associated with the end Cretaceous climate and sea-level changes are documented in the Rif mountain chain, in coastal basins, and in the massive marginal marine phosphorite sedimentation in the Middle and High Atlas, on the Moroccan Meseta and Sahara platform. In this review we provide a brief history of geological investigations and an overview of Cretaceous sedimentary archives, as well as a selection of research highlights and outstanding questions concerning the Cretaceous system in Morocco. The Cretaceous sedimentary archives from Morocco and adjacent coastal basins still retain untapped potential to further contribute to our understanding of global eustatic sea-level changes and the response of the oceans and marine biota in upwelling driven oxygen minimum zones under greenhouse climate conditions.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Dinosaurs were thriving at the beginning of the Cretaceous, and yet major changes had occurred across the Jurassic–Cretaceous boundary. The sauropods were replaced by ornithopods as dominant herbivores, which has been explained by many ecological scenarios, including the replacement of gymnosperms by angiosperms as dominant land plants. The ornithischians went on to radiate substantially in the mid and Late Cretaceous, with the key clades (hadrosaurs, ceratopsians, ankylosaurs) specializing in different feeding modes and diets, and reaching huge abundance in many faunas. New computational methods allow palaeobiologists to assess aspects of the palaeobiology, macroecology and macroevolution of dinosaurs through the Cretaceous in testable and repeatable ways. These new approaches have shed light on many mysteries, such as whether dinosaurs ate flowers, why the hadrosaurs were so successful and why some theropods became larger or smaller, or switched from carnivory to herbivory. There are further debates around the final demise of dinosaurs, where regional and global data suggest the group was in decline through the latter part of the Late Cretaceous before they were finished by the asteroid impact.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Amber first became relatively abundant and widespread in the geological record during the Cretaceous period. It originated often as copious resin production by a variety of incompletely understood coniferous trees, generally under humid climates, but not excluding seasonal aridity. Study of insect and other organic inclusions only commenced in the twentieth century, but has expanded considerably since then, with several thousand taxa now described. Cretaceous amber insects can be exquisitely preserved in three dimensions, although tend to be biased towards smaller individuals that lived in the local forest environment. They are therefore complemented by the Cretaceous rock record, which sampled larger insects and other habitats. As well as the fine morphological detail exhibited by the amber insect inclusions, various behaviours and interactions unlikely to be otherwise preserved can be found frozen in time, such as brooding behaviour and the entrapment of insects in spiders’ webs. Insects in amber also provide important information about evolutionary changes over the course of the Cretaceous, including the rise of eusociality and angiosperm pollination.</jats:p>

<jats:title>Abstract</jats:title> <jats:p> Following the breakup of Pangaea, many rifted margins of the Americas became carbonate platforms. During the Cretaceous, these platforms, as well as those associated with volcanic arcs, were populated by rudist bivalves that underwent a major radiation from the Early to Late Cretaceous. Carbonate platform development was episodic with major platforms represented by the Hauterivian to early Aptian, the early to late Albian and the Campanian to Maastrichtian. Different rudist bivalves characterised different phases of platform development. The Hauterivian to Aptian saw the rise of the Rethinae and Caprinidae, and was terminated by OAE1a. The Albian saw the rise of the Caprinuloideina and Youngicaprininae together with the first radiolitids. The Cenomanian is poorly understood in term of rudist bivalve development and the effects of the C-T boundary event (OAE2) are not well documented in the Americas. The Turonian to Maastrichtian saw a major radiation at the genus level of the rudists - hippuritids were initially represented by cosmopolitan genera, but through the late Santonian to early Campanian these were replaced by endemic genera. The radiolitids and antillocaprinids also underwent major radiations at this time, and numerous new endemic taxa characterised the carbonate platforms of the Americas. The Cretaceous-Paleogene boundary event decimated the carbonate platforms of the Americas and wiped out the rudist bivalves. Two new radiolitid genera are described: <jats:italic>Vermuntia</jats:italic> and <jats:italic>Thiadensia</jats:italic> . </jats:p>

<jats:title>Abstract</jats:title> <jats:p>The Upper Cretaceous Coon Creek Formation type-locality in McNairy County, Tennessee, is an exceptional marine invertebrate lagerstattäte that was deposited in a nearshore reentrant into the ancestral continent of Appalachia. Extensive taxonomic analysis of the macrofauna has been done for over 100 years. However, documentation of the microfossil component at the type-locality has largely been ignored. This paper provides analysis of calcareous microfossils (benthic and planktic foraminifera, calcareous nannofossils, and ostracods) and palynomorphs (pollen, spores, algal remains, and dinoflagellates) for detailed age control and information regarding environment of deposition. The Coon Creek type-locality is late Campanian (76.8-76.0 Ma) in age and was deposited in 35-60 m water depths. Calcareous nannofossil assemblages suggest that there was an influence of colder water through time, possibly by a connection to the northern Western Interior Seaway. The complex interplay between currents of the Gulf of Mexico and the Western Interior Seaway, upwelling and runoff influenced the paleoenvironment. Increased influx of freshwater palynomorphs near the top of the section suggests placement proximal to the paleoshoreline and that weathering increased through time. Changes in the dinoflagellate assemblage are linked to a mosasaur mass mortality event and the presence of a harmful agal bloom.</jats:p>

<jats:title>Abstract</jats:title> <jats:p> Stable isotope data (δ <jats:sup>13</jats:sup> C, δ <jats:sup>18</jats:sup> O, <jats:sup>87</jats:sup> Sr/ <jats:sup>86</jats:sup> Sr) of fossil carbonate shells are widely used throughout the Phanerozoic for stratigraphical dating and palaeoenvironmental reconstructions. The incorporation of δ <jats:sup>13</jats:sup> C <jats:sub>carb</jats:sub> is controlled by various factors, making its interpretation ambiguous. The analyses of co-occurring pristine carbonate shelled organisms, which occupied different ecological nitches during their lifetime, will help to better understand the effect of biological parameters (food sources, biofractionation) on the carbonate composition </jats:p> <jats:p> We have studied the geochemistry (elements, δ <jats:sup>13</jats:sup> C <jats:sub>carb</jats:sub> , δ <jats:sup>18</jats:sup> O <jats:sub>carb</jats:sub> , <jats:sup>87</jats:sup> Sr/ <jats:sup>86</jats:sup> Sr) of eight well preserved macrofossils (corals, oysters, gastropod, ammonite, belemnites) of earliest Albian age (112 ma). The up to 5‰ varying δ <jats:sup>13</jats:sup> C <jats:sub>carb</jats:sub> data of the aragonitic and calcitic skeletons of these organisms with different feeding strategies (primary, secondary, tertiary consumers) were used to reconstruct a food-chain. The outstanding low δ <jats:sup>13</jats:sup> C <jats:sub>carb</jats:sub> findings of belemnites are explained by the incorporation of larger amounts of metabolic carbon into the skeletons of these active predators. The findings suggest that the δ <jats:sup>13</jats:sup> C <jats:sub>carb</jats:sub> signal of the different organisms is controlled by a) their food source and b) subsequent biofractionation. The here discussed approach to interpret δ <jats:sup>13</jats:sup> C <jats:sub>carb</jats:sub> data may help in future to reconstruct past food-webs. </jats:p> <jats:p content-type="supplementary-material"> Supplementary material at <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" specific-use="dataset is-supplemented-by" xlink:href="https://doi.org/10.6084/m9.figshare.c.6906680">https://doi.org/10.6084/m9.figshare.c.6906680</jats:ext-link> </jats:p>

<jats:title>Abstract</jats:title> <jats:p>Defined in the Provence region of France, the rudist-bearing Urgonian Limestone is typical of northern Tethyan shallow-marine carbonate series, and is dated based on benthic fauna and flora, calcareous nannofossils, and ammonites. This contribution reports on recent findings that refine the stratigraphy of the Urgonian Limestone in the western Swiss Jura and the Helvetic Alps of Switzerland. In the former location, the high-resolution facies and isotope analysis of samples permit the identification of major periods of subaerial exposure while a diverse assemblage of calcareous nannofossils indicates a Barremian age for the Urgonian deposits. In the latter location, biostratigraphic data indicate a Late Barremian - Early Aptian age for Urgonian deposits while the repartition of facies along a proximal-to-distal transect highlights the Late Barremian progradation of the platform. The detailed understanding of the stratigraphy of Urgonian deposits in these regions inscribes them into a broader context that acknowledge paleoclimatic and paleoenvironmental conditions. A warmer and more humid climate prone to continental weathering and transport of nutrient to epicontinental sea characterized the Early Barremian; this was detrimental to the health of carbonate-producing benthic ecosystems. In the Late Barremian, a reduced nutrient supply allowed Urgonian communities to thrive.</jats:p>