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We propose a considerably revised taxonomy and phylogeny for Albian-Maastrichtian planispiral planktonic foraminiferal species that have traditionally been included in Globigerinelloides. The revised taxonomy is necessary because of a ~6 m.y. gap between the extinction of planispiral species during the late Aptian and the next younger occurrence of planispiral species in the middle Albian. Our stratophenetic taxonomic groupings utilize ontogenetic morphometric data, shell wall ultrastructure, and general morphologic features observed from Scanning Electron Microscope and X-radiograph images of primary type specimens and globally distributed hypotype specimens. The planispiral lineage Laeviella n. gen., whose type species is La. bentonensis (Morrow), first appeared in the middle Albian and is postulated to have evolved from the evolutionary series Ticinella primula Luterbacher-Laviella primuloides n. sp. Laeviella is characterized as having a smooth to finely pustulose wall texture and a moderate chamber size increase rate. Two additional species, La. tururensis (Bronnimann) and La. bollii (Pessagno), are included in Laeviella with the youngest species of the genus, La. bollii, becoming extinct during the late Campanian. Planohedbergella, with Plh. aspera (Ehrenberg) as its type species, is revised to include 10 species that show a wide variation in chamber arrangement, wall microstructure and test morphology, but all have a moderately to coarsely pustulose wall texture on some or most final whorl chambers. Its stratigraphic range is from the late Albian-Cretaceous/Paleogene boundary. The oldest species is Plh. ultramicra (Subbotina), which evolved from Planomalina pulchella Todd and Low during the late Albian. Planohedbergella circularis n. sp. is described as a new late Campanian-Maastrichtian species representing forms with evolute coiling, a large number of final whorl chambers, and a slow chamber size increase rate. Polycamerella n. gen. is described as a monospecific genus, with Po. tardata n. sp. as the type species. It is a small, biapertural form with a very slow chamber expansion rate and a stratigraphic range from the late Campanian-Maastrichtian. The ancestor of Po. tardata, is tentatively identified as Plh. ultramicra.

Distinctive and taxonomically relevant morphological differences exist between the original drawings of Archaeoglobigerina cretacea illustrated by d'Orbigny (1840) and the lectotype designated by Banner & Blow (1960), particularly regarding the equatorial periphery, which is rounded in the former and double-keeled in the latter specimen. Such differences would suggest that they are not conspecific, but this hypothesis cannot be easily tested because d'Orbigny's drawings likely represent a synthesis of observations on several specimens rather than a single individual and the slide intended to contain the lectotype is empty.In this study, we have re-examined the A. cretacea type specimens deposited in the d'Orbigny collection at the Muséum National d'Histoire Naturelle in Paris and samples from one of the type localities (Kent, SE England) with the aim to reconstruct d'Orbigny's species concept, clarify its morphological features, and better constrain its stratigraphic distribution.Our study suggests that d'Orbigny's concept for A. cretacea was broad and included unkeeled as well as double-keeled morphotypes. However, assemblages from Kent yield common and large-sized specimens conspecific with the lectotype in the middle Santonian-lower Campanian, while morphotypes resembling the drawings of d'Orbigny are absent. Accordingly, five topotype specimens from the lower Campanian of Kent are herein illustrated in order to stabilize the species concept adopted over the last 60 years on the basis of the lectotype drawing and description. All topotypes possess a wide imperforate peripheral band and a moderately to weakly developed double-keeled periphery. Finally, the description of A. cretacea is emended to exclude specimens that do not possess an imperforate peripheral band and to include those that show curved and weakly beaded spiral sutures.

Massive release of volcanic gases into the ocean-atmosphere system during geologically short periods of time is often invoked as the main trigger of episodes of global paleoenvironmental perturbations, and a link has been proposed between some mass extinction events, OAEs and the activity of Large Igneous Provinces. However, establishing a precise correlation between sections where the volcanic deposits of LIPs are preserved and marine sections, which hold the key records of global biotic and paleoenvironmental changes, is not a trivial effort. During the past 15 years, mercury concentration in sedimentary rocks has emerged as a useful proxy for bracketing intervals of LIPs activity, because Hg is primarily introduced into the atmosphere, and from there into the sedimentary record, through volcanic inputs. The end-Triassic extinction (ETE), one of the big five mass extinction of the Phanerozoic, has been linked to the volcanic activity of the Central Atlantic Magmatic Province (CAMP). Correlation by radiochronologic dating of CAMP basalts has been further supported in recent years by detection of mercury anomalies in marine deposits of key sections recording the ETE, including the Kuhjoch GSSP in the Northern Calcareous Alps (Austria), St Audrie’s Bay (UK) and the New York Canyon (Nevada, USA). However, as the Hg proxy is investigated in more and more sections, a complicated pattern is emerging, which indicates that depositional and diagenetic processes can produce Hg anomalies unrelated to LIP magmatism. For this reason, it is important to test the proxy across a wide range of depositional environments. In this study, we present a high-resolution record of Hg concentration in an uppermost Triassic-Lower Jurassic carbonate platform section of the Pelagonian Domain (Greece). In this section the ETE is marked by the abrupt disappearance of megalodontid bivalves and involutinid benthic foraminifers. By integrating bio- and high-resolution carbon isotope stratigraphy, we correlate the studied section with reference sections for which a record of Hg concentration across the ETE has been published. Furthermore, we use facies analysis and geochemistry to unravel the role of local depositional and diagenetic processes in overprinting the global signal of volcanism on Hg concentration.

The End Triassic Extinction (ETE), one of the “big five” of the Phanerozoic, caused a severe loss of biodiversity both in the continental and in the marine realm. The ETE has been linked with enhanced volcanism of the Central Atlantic Magmatic Province (CAMP), which injected a large amount of CO2 in the ocean-atmosphere system, triggering major paleoenvironmental perturbations including climate change, ocean acidification and marine anoxia.In the marine realm, shallow-water benthic biocalcifiers of subtropical carbonate platforms were severely affected, with reef-building scleractinian corals and calcisponges, large megalodontid bivalves, involutinid benthic foraminifers and dasycladalean algae being among the most famous victims. In the classical localities of the Northern Calcareous Alps and Transdanubian Range, the ETE coincides with the demise of the Dachstein-type carbonate platform, which is generally sharply overlain by relatively deep-water facies of outer ramp to basinal environment. This stratigraphy has been interpreted as recording subaerial exposure of the carbonate platform, associated to a sea-level drop in the late Rhaetian that generated a hiatus of variable and generally poorly constrained duration, followed by drowning during transgression in the Early Jurassic.A different stratigraphic evolution is recorded in some areas of the southern Tethyan margin (i.e., the southern Apennines and Sicily in southern Italy, Greece, the United Arab Emirates and Oman) where carbonate platform facies persist across the Triassic/Jurassic boundary. Stratigraphic sections in these areas are particularly significant to document the evolution of biodiversity of shallow-water benthic biocalcifiers across the ETE interval.In this study we present new data on the stratigraphic distribution and changes in abundance of benthic foraminifers in two latest Triassic–earliest Jurassic carbonate platform sections of the southern Apennines (Italy) and Pelagonian domain (Greece). We document a decline in diversity and abundance of involutinid benthic foraminifers predating the extinction of several genera in the latest Rhaetian. Carbon isotope profiles of the studied sections show a complicated pattern of repetitive high-frequency negative excursions, seemingly related to local paleoenvironmental and/or early diagenetic features. However, by integrating bio- and carbon isotope stratigraphy we are able to correlate the studied sections with other persistent carbonate platform sections and with reference sections of the Lombardy Basin and of the Northern Calcareous Alps.

The upper Cenomanian – lower Turonian is a key-stratigraphic interval, as it encompasses the Late Cretaceous supergreenhouse and a major perturbation of the global carbon cycle (i. e., Oceanic Anoxic Event 2) as evidenced by a global positive carbon isotope excursion and by the nearly world-wide deposition of organic-rich marine facies. A turnover in planktonic foraminiferal assemblages and in other marine organisms is documented across this stratigraphic interval, but reconstruction of the timing and identification of the cause and effect relationships between environmental perturbations and organism response require a highly-resolved stratigraphic framework. The appearance and extinction levels of planktonic foraminiferal species generally allow accurate intra- and supra-basinal correlations. However, bioevents cannot be assumed to be globally synchronous, because the stratigraphic and geographic distribution of species is modulated by ecological preferences exhibited by each taxon and controlled by oceanic circulation, often resulting in earlier or delayed events in certain geographic areas (i. e., diachronous datums). The aim of this study is to test the synchronicity of the planktonic foraminiferal bioevents recognized across the C/T boundary and to provide the most reliable sequence of events for correlation of low to mid-latitude localities. For this purpose, we have compiled a highly-resolved biostratigraphic analysis of the European reference section for the C/T boundary at Eastbourne, Gun Gardens (UK), and core S57 (Tarfaya, Morocco), and correlated the sequence of bioevents identified with those recorded in other coeval sections available in the literature, including the GSSP section for the base of the Turonian Stage at Rock Canyon, Pueblo (Colorado), where we calculated reliable estimates of planktonic foraminiferal events that are well-constrained by radioisotopically and astrochronologically dated bentonite layers. Results indicate that the extinctions of Thalmanninella deeckei, Thalmanninella greenhornensis, Rotalipora cushmani and "Globigerinelloides" bentonensis in the latest Cenomanian are reliable bioevents for correlation. In addition, our analysis highlights other promising lowest occurrences (LOs) that need to be better constrained by bio- and chemostratigraphy, including the LO of Marginotruncana schneegansi falling close to the C/T boundary. By contrast, the appearance of Helvetoglobotruncana helvetica and of some Dicarinella species, the extinction of anaticinellids and the onset of the "Heterohelix" shift are likely diachronous across low to mid-latitude localities. Finally, our study suggests that different species concepts among authors, different sample size and sampling resolution, as well as species paleoecology are important factors that control the stratigraphic position at which bioevents are identified.

The Plenus Cold Event (PCE) temporarily interrupted the supergreenhouse conditions exacerbated during much of the Cenomanian–Turonian Oceanic Anoxic Event 2 (OAE 2). The PCE is coeval to the occurrence of Boreal benthic macroinvertebrates and of the nektonic belemnite Praeactinocamax plenus (after which the event is named) in Europe, and to the re-oxygenation of bottom waters in the Northern Hemisphere. However, its effects on the sea-surface circulation are unknown and evidence for changes in the biogeography of planktonic organisms are limited to the equatorward migration of the dinoflagellate cysts grouped in the Cyclonephelium compactum–membraniphorum morphological plexus. This study presents new planktonic foraminiferal quantitative data from two complete OAE 2 records of the Anglo-Paris (Eastbourne, SE England) and Vocontian (Clot Chevalier, SE France) basins that registered the equatorward pulse of Boreal macroinvertebrates during the PCE and have been extensively studied for bio- and chemostratigraphy. At the onset of OAE 2 (before the PCE), planktonic foraminifera are mainly represented by oligo-mesotrophic Tethyan taxa (rotaliporids and whiteinellids) in both localities, but this assemblage is sharply replaced by cold and meso-to-eutrophic species (praeglobotruncanids, dicarinellids and muricohedbergellids) during the PCE. The cold-water assemblage shows strong affinities with the coeval fauna of the Norwegian Sea and yields the Boreal endemic species Muricohedbergella kyphoma and Praeglobotruncana plenusiensis. This observation combined with previously published data collected in other localities of the Northern Hemisphere and on other fossil groups suggests a ~20° equatorward expansion of the Boreal marine bioprovince during the PCE. Moreover, contrarily to the nektonic belemnitellids that were able to move independently of ocean circulation, planktonic organisms are passively transported by currents and changes in the planktonic foraminiferal assemblages documented in the Anglo-Paris and Vocontian basins have been interpreted to reflect the transition from a dominant influence of warm, saline, and thermally stratified waters carried by the proto-Gulf Stream before the PCE to cold and low-saline Boreal waters originated in the Norwegian Sea during the PCE. We suggest that such changes were forced by the equatorward shift of the proto-Arctic Front (i.e., the boundary between warm saline Tethyan-Atlantic and cold low-saline Boreal waters) from offshore Norway to Southern England. In this southerly position, the proto-Arctic Front represented an oceanographic barrier that limited the influence of the proto-Gulf Stream in the Anglo-Paris Basin, and favored the inflow of Boreal waters from the North to the European epicontinental basins. The sea-surface cooling and equatorward expansion of Boreal planktonic assemblages during the PCE are of the same order of magnitude of those reconstructed between some glacial and interglacial intervals of the Plio-Pleistocene. Despite obvious differences between Cretaceous and Plio-Pleistocene paleogeography and climate dynamics, this study reviews the extent of environmental changes occurred during the PCE, provides evidence for a profound re-organization of the sea-surface circulation patterns and a more comprehensive overview of the equatorward migration of Boreal marine communities in the Northern Hemisphere.

A new relational taxonomic database for planktonic foraminifera (Pforams@microtax) has been constructed and is now freely available online at http://www.mikrotax.org. It represents amajor advance from its predecessor, the CHRONOS online taxonomic database, which has served the research community since 2005. The benefits of the new database to the research and industrial biostratigraphic communities are many, as it will serve as an immediately accessible taxonomic guide and reference for specialists and non-specialists alike by providing access to a wealth of information and images from original authors and from expertswho have inserted recent authoritative updates to planktonic foraminiferal taxonomy, phylogeny and biostratigraphy. The database will be continually updated and used as a guide for training current and future generations of students and professionals who will be able to self-educate on planktonic foraminiferal taxonomy and biostratigraphy. Further investigation of species traditionally included in the Cretaceous genera Heterohelix, Globigerinelloides, Marginotruncana, and Globotruncana is required to exclude the use of polyphyletic morphotaxa. The taxonomy for Paleogene planktonic foraminifera is quite stable following publication of the Paleocene, Eocene, and Oligocene taxonomic atlases, but revisions to the taxonomy and phylogeny of Neogene taxa are needed to incorporate results from genetic sequencing studies and recent biostratigraphic observations.

A 101 m thick stratigraphically complete late Coniacian–early Santonian (ca 89 to 83 Ma) sedimentary sequence drilled in Tanzania (Tanzania Drilling Project Site 39) allows, for the first time, examination of the planktonic foraminiferal biostratigraphy and evolution, the depositional history, and geochemical patterns of the subtropical–tropical Indian Ocean region. The sedimentary succession corresponds to an outer shelf to upper slope setting and is dominated by calcareous clayey siltstones and mudstones. The occurrences of Tethyan marker species enable application of the tropical biozonation including identification of the Dicarinella concavata and D. asymetrica Zones. In addition, Tanzania Drilling Project Site 39 is proposed as reference section for the Coniacian/Santonian boundary in the Indian Ocean with the boundary placed at the lowest occurrence of Globotruncana linneiana in agreement with the GSSP stratotype (Spain). The record at Tanzania Drilling Project 39 provides a unique opportunity to document the planktonic foraminiferal evolution in a subtropical marginal sea environment during a key period in their evolutionary history characterized by a major radiation among the deep-dwelling taxa. Combined documentation of lithological and geochemical changes (%CaCO3, %Corg, δ13Ccarb and δ18Ocarb) reveal a setting influenced by continental-derived nutrients in the D. concavata Zone (Lindi Formation) with a change to higher carbonate production and reduced surface water primary productivity in the overlying D. asymetrica Zone (Nangurukuru Formation). Planktonic foraminiferal assemblage changes mirror the depositional and geochemical trends and indicate a progressive shift from a more eutrophic to a more oligotrophic regime through time. At the local scale, this palaeoceanographic scenario is consistent with the deepening of coastal Tanzania in response to the Late Cretaceous marine transgression registered in south-east Tanzania. Because the tectonic evolution and sea-level rise along the East Africa continental margin is superimposed on the Coniacian–Campanian global long-term sea-level high, this study hypothesizes that the epicontinental invasion of blue waters may have favoured radiation among deep-dwelling taxa. This article is protected by copyright. All rights reserved.

© 2016 Geological Society of America. The ~35-m.y.-long Late Cretaceous greenhouse climate has been the subject of a number of studies, with emphasis on the Cenomanian-Turonian and late Campanian-Maastrichtian intervals. By contrast, far less information is available for the Turonian-early Campanian interval, even though it encompasses the transition out of the extreme warmth of the Cenomanian-Turonian greenhouse climate optimum and includes an ~3-m.y.-long mid-Coniacian-mid-Santonian interval when planktonic foraminifera underwent a large-scale, but poorly understood, turnover. This study presents ~1350 δ18O and δ13C values of wellpreserved benthic and planktonic foraminifera and of the

The Cenomanian–Turonian boundary interval is generally considered a critical time for planktonic foraminifera due to the environmental perturbations associated with Oceanic Anoxic Event 2. However, only the rotaliporids became extinct at the onset of the event, whilst several lineages evolved and/or diversified. This remarkable morphologic plasticity is often overlooked in the literature, partly because a number of stratigraphic sections have only been studied in thin-section due to the degree of lithification of the samples. Improved documentation of the morphological variability of planktonic foraminifera and better defined species concepts are required in order to improve biostratigraphy, particularly as Helvetoglobotruncana helvetica is an unreliable marker for the base of the Turonian. At the same time, detailed study of the planktonic foraminiferal response to OAE 2 demands a more profound knowledge of the assemblage composition. We present new biostratigraphic, taxonomic, and quantitative data for planktonic foraminiferal species from the Clot Chevalier section (Vocontian Basin, SE France), with the aim of (1) providing a detailed biostratigraphic analysis of the section, (2) documenting the morphological plasticity of specimens in this time interval and stabilizing species concepts, and (3) identifying promising markers to improve the resolution of the present biozonation and allow regional correlation. Samples were processed with acetic acid to extract isolated planktonic foraminifera. Assemblages were assigned to the upper Cenomanian Rotalipora cushmani Zone and to the uppermost Cenomanian–lowermost Turonian Whiteinella archaeocretacea Zone. Planktonic foraminiferal bioevents and assemblage composition identified at Clot Chevalier are compared with the well-studied Pont d'Issole section located ca. 15 km to the NE, highlighting similarities and differences in the species occurrences that may complicate the stratigraphic correlation between the two sections. The results of our study support the validity and common occurrence of species that have been misidentified and/or overlooked in the literature (i.e., Dicarinella roddai, Praeglobotruncana oraviensis, Marginotruncana caronae) and indicate that primitive marginotruncanids evolved before the onset of OAE 2, although species diversification occurred only after the event. Moreover, we believe that the first appearance of P. oraviensis might represent a promising bioevent for approximating the Cenomanian/Turonian boundary, after calibration with bio- and chemostratigraphically well-constrained sections. Finally, we describe three new trochospiral species, named “Pseudoclavihedbergella” chevaliensis, Praeglobotruncana pseudoalgeriana and Praeglobotruncana clotensis.

The latest Cenomanian Oceanic Anoxic Event (OAE) 2 represents one of the most extreme perturbations of the global carbon cycle. Planktonic foraminiferal events, variations in the taxonomic composition of assemblages (e.g., appearances, extinctions, temporary crisis of certain taxa) and their correlation with changes in the physico-chemical properties of surface waters are essential to reconstructing the consequences of OAE 2 on this group of calcareous microfossils. We present the results of a high-resolution biostratigraphic and taxonomic study of planktonic foraminifera performed at Eastbourne (SE England), representing the most expanded, complete and well-calibrated OAE 2 record in Europe. In this stratigraphic section, we identify a sequence of step-wise extinctions (i.e., Thalmanninella and Rotalipora species, and “Globigerinelloides” bentonensis) that are followed by an eclipse (temporary disappearance) of planispiral taxa and of hedbergellids with radially elongated chambers. These events are consistently found in approximately coeval stratigraphic intervals across low to mid-latitudes, suggesting that they were controlled by wide-scale environmental perturbations. Moreover, this study suggests that the extinction of rotaliporids might have been influenced by climate changes (i.e., warming for Thalmanninella and cooling during the Plenus Cold Event for Rotalipora) at the onset of OAE 2, whereas the eclipse of planispiral taxa and hedbergellids with radially elongated chambers during the second half of OAE 2 was likely related to enhanced productivity and mixing of surface waters potentially associated to warming after the PCE for planispirals. Finally, we identify two short-range species (Muricohedbergella kyphoma and Praeglobotruncana plenusiensis n. sp.) that co-occur with boreal macrofossils at Eastbourne and might represent the first evidence for a planktonic foraminiferal PCE fauna. The long ranging species Praeglobotrucana gungardensis n. sp. is described as new.

Wall texture and ornamentation in Cretaceous planktonic foraminifera, as with modern and Cenozoic taxa, are generally considered to be genetically controlled and thus taxonomically significant. For instance, the iterative development of meridional ornamentation is a diagnostic criterion used to discriminate between the Santonian–early Campanian genus Costellagerina , and the Campanian–Maastrichtian genus Rugoglobigerina . An alternative ecophenotypic explanation for differences based on observed poleward decreases in meridional ornamentation has not been widely accepted largely due to absence of evidence. Our study of Rugoglobigerina specimens recovered at three mid-low latitude localities (Exmouth Plateau, eastern Indian Ocean; Shatsky Rise, northwestern Pacific Ocean; Eratosthenes Seamount, eastern Mediterranean) confirms that meridional ornamentation is a primary character of their tests, but development of this feature is highly variable throughout the geographic and stratigraphic distribution of the genus. Within assemblages of Rugoglobigerina , there is a continuous morphological range from specimens with well-developed costellae arranged in a meridional pattern to specimens with relatively short ridges that are randomly oriented to meridionally aligned. Stable isotope (δ 13 C and δ 18 O) analyses indicate that specimens showing a more strongly developed meridional ornamentation consistently yield higher δ 13 C values than co-occurring less ornamented morphotypes at each examined locality, whereas patterns in the δ 18 O values are site-dependent. Interpretation of these patterns is not simple and might be related to different controlling factors acting together or separately. Potential explanations for the differential development of the ornamentation include: (1) adaptation to different ecological niches within a population, (2) species-level genetic differences, (3) variation in metabolic rate or activity within individuals, and (4) changes in the seawater carbonate ion saturation through space and time, including seasonality. In addition, we highlight the difficulty of discriminating between Rugoglobigerina and Costellagerina when they co-occur in lower Campanian deposits and among Rugoglobigerina , Costellagerina and Archaeoglobigerina at high latitude localities where species placed in all three genera show very similar shell morphology and ornamentation. Finally, our study challenges the general assumption that some external features of the wall are sufficiently reliable for taxonomic discrimination of Cretaceous planktonic foraminifera. This latter conclusion suggests that environmental conditions such as water temperature, water column stratification, nutrient concentration and carbonate ion saturation may have played a key role in triggering the external expression of genetically controlled wall ornamentation in the planktonic foraminifera.

The Santonian–Campanian interval is of particular interest as it encompasses a cooling trend after the Late Cretaceous greenhouse maximum warmth of the Turonian as well as a possibly related major faunal turnover among planktonic foraminifera. The recovery of pristinely preserved planktonic foraminifera from Santonian–Campanian sequences in southeastern Tanzania allows examination of faunal changes and documentation of species-specific stable isotope (δ 13 C and δ 18 O) signatures. These isotopic data are ideal for inferring species paleoecological preferences and for tracing major paleoceanographic changes. This study reports the first δ 18 O and δ 13 C data generated on “glassy” specimens of Marginotruncana coronata , M. undulata , M. marginata , and M. pseudolinneiana and Sigalia carpatica . Additional results from Shatsky Rise (Ocean Drilling Program Leg 198, Hole 1210B) and Exmouth Plateau (ODP Leg 122, Hole 762C) provide geographic control on species habitat preferences and paleoceanographic context. Isotopic analyses suggest that double-keeled species, including Globotruncana bulloides , Contusotruncana fornicata , C. plummerae and probably marginotruncanids, inhabited the surface mixed layer, whereas the biserial Gublerina rajagopalani was a permanent thermocline dweller. Thus, our study confirms recent suggestions that the depth-distribution models based on shell morphology and analogies with modern taxa are not applicable. At all the examined localities, changes in planktonic foraminiferal assemblages are used to define several ecological intervals, each one characterized by a distinctive taxonomic composition and/or increasing/decreasing species diversity. Combined geochemical and paleontological observations suggest that, by the middle–late Campanian, a stratified upper water column developed in Tanzania while less stratified and/or mesotrophic conditions prevailed at Shatsky Rise and Exmouth Plateau.

The 2008 Tanzania Drilling Project (TDP) expedition recovered common planktonic foraminifera (PF), calcareous nannofossils (CN) and calcareous dinoflagellates with extraordinary shell preservation at multiple Cenomanian–Campanian sites that will be used for paleoclimatic, paleoceanographic, and biostratigraphic studies. New cores confirm the existence of a more expanded and continuous Upper Cretaceous sequence than had previously been documented in the Lindi and Kilwa regions of southeastern coastal Tanzania. This TDP expedition cored 684.02m at eight Upper Cretaceous sites (TDP Sites 28–35) and a thin Paleocene section (TDP Site 27).TDP Sites 29, 30, 31 and 34 together span the lowermost Turonian to Coniacian (PF Whiteinella archaeocretacea to Dicarinella concavata Zones and CN Zones UC6a–9b), with TDP Site 31 being the most biostratigraphically complete Turonian section found during TDP drilling. A discontinuous section from the Santonian–upper Campanian (PF D. asymetrica to Radotruncana calcarata Zones and CN Zones UC12–16) was collectively recovered at TDP Sites 28, 32 and 35, while thin sequences of the lower Cenomanian (PF Thalmanninella globotruncanoides Zone and CN subzones UC3a–b) and middle Paleocene (Selandian; PF Zone P3a and CN Zone NP5) were cored in TDP Sites 33 and 27, respectively. Records of δ13Corg and δ13Ccarb from bulk sediments generated for all the Cretaceous sites show largely stable values through the sections. Only a few parallel δ13Corg and δ13Ccarb shifts have been found and they are interpreted to reflect local processes. The δ18Ocarb record, however, is consistent with Late Cretaceous cooling trends from the Turonian into the Campanian. Lithologies of these sites include thick intervals of claystones and siltstones with locally abundant, finely-laminated fabrics, irregular occurrences of thin sandstone layers, and sporadic bioclastic debris (e.g., inoceramids, ammonites). Minor lithologies represent much thinner units of up to medium-grained, massive sandstones. The %CaCO3 (∼5–40%) and %Corg (∼0.1–2%) are variable, with the highest %CaCO3 in the lower Campanian and the highest %Corg in the Turonian. Lithofacies analysis suggests that deposition of these sediments occurred in outer shelf-upper slope, a setting that agrees well with inferences from benthic foraminifera and calcareous dinoflagellates.

Globotruncanita insignis (Gandolfi, 1955) is a planktonic species commonly recognized in Late Cretaceous foraminiferal assemblages, but uncertainty about its morphologic variability and phyletic relationships have led to different interpretations of it. The taxon was considered to be morphologically and evolutionary related to Globotruncana rosetta (Carsey, 1926), phyletically linked to Globotruncanita elevata (Brotzen, 1934), or a junior synonym of the latter species. In addition, the neotype that replaced the lost holotype caused a taxonomic debate and compromised the identification of G. insignis , which has been assigned to both Globotruncanita and Globotruncana. This study resolves the taxonomic problems and reconstructs the phyletic lineage of this species on the basis of a continuous sequence of exceptionally well preserved and highly diversified planktonic foraminiferal assemblages in the Contusotruncana plummerae and Radotruncana calcarata zones, recently recovered from southeastern Tanzania drillholes. In addition to common G. insignis that characteristically have a strongly convex umbilical side, we recognized succession of morphotypes intermediate between Globotruncanita stuartiformis and G. insignis that demonstrates an ancestor–descendant relationship between the two taxa and further validates the assignment of G. insignis to Globotruncanita . Moreover, our results confirm that the neotype falls in the same phyletic lineage, but it represents a primitive form of G. insignis .

The Late Cretaceous ‘greenhouse’ world witnessed a transition from one of the warmest climates of the past 140 million years to cooler conditions, yet still without significant continental ice. Low-latitude sea surface temperature (SST) records are a vital piece of evidence required to unravel the cause of Late Cretaceous cooling, but high-quality data remain illusive. Here, using an organic geochemical palaeothermometer (TEX86), we present a record of SSTs for the Campanian–Maastrichtian interval (~83–66 Ma) from hemipelagic sediments deposited on the western North Atlantic shelf. Our record reveals that the North Atlantic at 35 °N was relatively warm in the earliest Campanian, with maximum SSTs of ~35 °C, but experienced significant cooling (~7 °C) after this to, The Late Cretaceous experienced significant cooling, yet a lack of low-latitude records mean the regional extent of this cooling is poorly constrained. Linnert et al. present a TEX86 sea surface temperature record from a palaeolatitude of ~35 °N and show that Late Cretaceous cooling was global in nature.