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The species Turborotalita nikolasi first appeared immediately after the Cretaceous-Paleogene (K-Pg) boundary and is considered the progenitor of all Cenozoic normal perforate species. We present δ18O and δ13C isotope signals of T. nikolasi specimens and compare them with those of mixed-layer (Guembelina cretacea), thermocline (Subbotina trivialis and Chiloguembelina midwayensis), and deep water (Nuttalides truempyi) species with glassy shell preservation from São Paulo Plateau [Deep Sea Drilling Project (DSDP) Site 356]. Turborotalita nikolasi δ18O values are similar to those of G. cretacea, suggesting that both species cohabited the mixed layer. Values of δ13C for T. nikolasi are higher than those of all other planktic foraminiferal species, which may have been due to the presence of photosymbionts, and thus might represent the earliest known record of photosymbiosis for Cenozoic planktic foraminifera. Nuttalides truempyi δ13C values are remarkably high at Site 356, indicating low 12C abundance in deep waters, which could be related to reduced inefficiency of the biological pump in transporting 12C to the bottom of the ocean after the K-Pg boundary during the first ∼300 kyr of the Danian.

The Aptian–Albian interval is characterized by significant paleoclimatic, paleoceanographic, and paleogeographic changes, which in turn affected the distribution and evolution of marine ecosystems. Despite the importance of such studies, there have been few correlations between Aptian–Albian sections of the Tethys Sea and those of the South Atlantic Ocean. This interval, including the Aptian–Albian transition, is preserved in the deposits of the Riachuelo Formation (Sergipe–Alagoas Basin, Brazil) located in the South Atlantic Ocean; therefore, this location was chosen for drilling four new cores. The goals of this paper are as follows: (1) to explain the drilling operation carried out in the deposits of the Riachuelo Formation and the methods used; (2) to present a brief lithostratigraphic characterization of the holes and the paleomagnetic data of core SER-03; and (3) to describe the high potential of the cores recovered for additional investigation in the future. The lithostratigraphic units of the SER-01 core consist mainly of coarse- to fine-grained sandstone, shales, marls, and mudstones; the SER-02 core was excluded due to low recovery; the SER-03 core is mainly composed of fine-grained sediments (shale, marls, and packstone) and bears some ammonite shells; the lithology of core SER-04 is mainly sandstones. Magnetic susceptibility values (χlf and χhf) and frequency-dependent susceptibility (χfd) data suggest that the section is located within the Cretaceous Normal Superchron. Future studies on these cores integrating micropaleontological, paleoichnological, geochemical, stratigraphic, and paleomagnetic (e.g., relative intensity) data will allow for a better understanding of paleoceanographic and paleogeographic events related to the early evolution of the South Atlantic Ocean and how these events correlate to similar events in Tethyan sections.

The Early Cretaceous was dominated by greenhouse conditions and increases in ocean crust production rate, with critical climate, geography and oceanography changes and abrupt shifts in redox conditions in the oceans. Prior to the Aptian, regarding the Earth’s magnetic field, a high rate of polarity reversals dominated. However, thereafter, a period of polarity stability, known as the Cretaceous Normal Polarity Superchron (CNPS), was established for 34 Myr. Although, there are debates on the causes and consequences of these extreme events. The exact behavior of the geomagnetic field in this period is still poorly understood, and data from volcanic and sedimentary rocks are conflicting. The biostratigraphy data from the sedimentary succession from the Aptian-Albian interval in the Sergipe-Alagoas Basin (Brazil) are rare and correlations are weak with Tethyan realm. Since some of the major reservoirs of the terrestrial portion of the Sergipe-Alagoas basin are from Aptian-Albian ages the lack of age models brings difficulties to the oil industry. Magnetic parameters such as magnetic susceptibility, ARM, IRM, and magnetostratigraphy data were obtained with a resolution of 25 cm in the Core SER-03 from Sergipe-Alagoas Basin. The entire section varies 4 Myr, including the Aptian-Albian boundary. Here, we present preliminary environmental magnetism and magnetostratigraphic interpretation for this core. Therefore, these data will aid to develop an age model framework in order to assist this uncovered region and for future comparisons with Tethyan realm.

The planktic foraminifera from two sedimentary sequences of the Upper Cretaceous recovered by the Deep Sea Drilling Project (DSDP) Leg 80, Site 549 and Site 550 (Hole 550B) in the Goban Spur region were analysed in order to refine and integrate the zonal schemes for this area of the North Atlantic Ocean. In the studied intervals, 75 samples were analysed, and 88 species of planktic foraminifera were recognized, enabling the identification of the following biostratigraphic zones: Rotalipora cushmani (upper Cenomanian); Helvetoglobotruncana helvetica (lower Turonian); Dicarinella concavata (upper Turonian–Coniacian); Dicarinella asymetrica (upper Coniacian–Santonian); Racemiguembelina fructicosa and Abathomphalus mayaroensis (upper Maastrichtian). Two intervals in Hole 550B are likely correlative to composite biozones Pseudoguembelina palpebra/Gansserina gansseri (Campanian–Maastrichtian) and Racemiguembelina fructicosa/Abathomphalus mayaroensis (upper Maastrichtian). These zones indicate that the studied intervals were deposited from the late Cenomanian to the late Maastrichtian. The presence of high values (>6.6%) of Total Organic Carbon (TOC) in section 549-27-1 might be related to the Oceanic Anoxic Event 2 (OAE 2), globally recorded across the Cenomanian–Turonian boundary transition. The extinction of the Rotaliporidae family was observed in both sections and was associated with the onset of OAE2 in Site 549.

The Cretaceous-Paleogene (K-Pg) boundary extinction event affected planktic foraminiferal assemblages worldwide in a dramatic way, but deep sea benthic foraminiferal assemblages were not significantly impacted. However, possible impacts of massive early Danian volcanic eruptions, such as those related to the Deccan Traps, on benthic foraminiferal assemblages are not yet explored. Here we present geochemical and benthic foraminiferal data across the K-Pg boundary and within the earliest Danian interval at Deep Sea Drilling Project (DSDP) Site 356, located on the Sao Paulo Plateau, western South Atlantic Ocean. Maastrichtian to Danian benthic foraminiferal assemblages are well-preserved and suggest deposition at middle to lower bathyal paleodepths, under an oligotrophic regime with well-oxygenated bottom water conditions. As expected, the K-Pg boundary event did not significantly affect benthic foraminiferal assemblages at Site 356. However, during the early Danian, benthic foraminiferal species richness, heterogeneity, diversity and equitability presented overall opposite trends in relation to the Hg/TOC and Hg/CaCO3 ratios, as well as Hg concentrations, which we consider proxies for intensity of volcanic activity. Our results suggest a possible response of Danian middle to lower bathyal benthic foraminiferal assemblages at Site 356 to changes in bottom water condition possibly associated with massive volcanism eruptions.

In the present study, the planktonic foraminiferal distribution in a core section representing an interval between the Cretaceous/Paleogene (K/Pg) boundary and the end of the Paleocene (Danian/Selandian) from DSDP Site 356 (Sao Paulo Plateau, South Atlantic) was analyzed. The results point towards a gradual recovery of the marine pelagic ecosystem in the aftermath of the K/Pg mass-extinction event. The changes in distribution patterns and composition of the Danian planktonic foraminiferal assemblages are primarily related to the instability and changing conditions of oceanic surface waters. The quantitative analyses of the planktonic foraminifera showed that a series of speciation events took place in the Danian immediately after the K/Pg boundary, marking three distinct main intervals: (i) in the Pα zone, evidenced by the predominance of specimens that likely inhabited the most superficial portions of the water column (mixed layer), represented mainly by microperforated taxa ( Globoconusa , Guembelitria , Parvularugoglobigerina and Woodringina ). The occurrence of this group suggests poorly stratified water masses and a water column with meso-eutrophic conditions. In this interval, the first appearance of spines in the planktonic foraminifera ( Eoglobigerina , of the family Globigerinidae) evidences the development of a carnivorous habit; (ii) between zones P1a and P2 there is a continuous increase of species that inhabited the lower portion of the water column, in the thermocline and sub-thermocline, suggesting the recovery of the pelagic ecosystem with the development of a more stratified water column in mesotrophic to oligotrophic conditions; (iii) from zone P3 onwards, most of the planktonic foraminifera inhabited the lowest portions of the water column, together with the first occurrences of mixed-layer endosymbiont-bearing species such as Morozovella , Acarinina and Igorina .

Although intraspecific trait variability (ITV) is known to decrease with the increasing spatial extent, few studies have addressed how it behaves accross different ecological scales alongside short environmental gradients and which factors drive this variation. We verify whether functional traits of a characteristic species of riverine forests exhibit greater inter- (regional scale) than intra-population (local scale) ITV and whether environmental factors are affecting its functional traits. We sampled four populations of Gymnanthes klotzschiana from different geomorphological regions in southern Brazil and collected data of leaf area (LA), leaf dry matter content (LDMC) and total height from seven adult individuals per plot. We observed significant differences among populations and greater variability at the inter- than intra-population scale for LDMC and total height. Leaf area exhibited greater intra-population variation. Cation exchange capacity and available phosphorus affected positively LDMC. Base saturation influenced negatively total height. Difference between mean canopy height and mean height of G. klotzschiana exerted negative effects on LDMC and total height and positive effetcs on LA. Our results demonstrate LDMC and total height to be suitable functional traits for studies on ITV at the regional scale and reinforce the need of considering it in ecological studies, including on a regional scale.

Early Danian environmental perturbations related to carbon isotope negative excursions (CIEs) were recognized at Deep Sea Drilling Project (DSDP) Hole 516F, Rio Grande Rise. Within the first ~160 kyr of the Danian, environmental stability is evidenced by well‑oxygenated bottom waters, good carbonate preservation, and relatively high primary production. The preservation of carbonates and the oxygenation of the deep water decreased progressively, leading to the formation of red layers in the sediments between 65.86 Ma and 65.71 Ma. The onset of carbonate dissolution and the reduction in dissolved oxygen concentrations occurred approximately 50 kyr before the onset of the Dan-C2 event, and was probably related to the third volcanic event of the Deccan Traps (DT). Our results support the link between enhanced emissions of volcanic gasses and deep ocean carbonate dissolution and deoxygenation during the Early Danian. The CIEs at the Rio Grande Rise are positioned within the planktonic foraminiferal biozone P1b, suggesting that the first appearance of Subbotina triloculinoides within Chron C29r (at 65.89 Ma) is a diachronous datum.

Computational analysis applicability to paleontological images ranges from the study of the evolution of animals, plants and microorganisms to the habitat simulation of living beings from a specific epoch. It can also be applied in several niches, e.g. oil exploration, where several factors can be analyzed in order to minimize costs related to oil extraction. One specific factor is the characterization of the environment to be explored. This analysis can occur in several ways: use of probes, samples extraction, correlation with logs of other drilling wells and so on. During the samples extraction phase, the Computed Tomography (CT) is of extreme importance, since it preserves the sample and makes it available for several analyses. Based on 3D images generated by CT, analyses and simulations can be performed, and processes currently performed manually and exhaustively, can be automated. In this work, we propose and validate a method for fully automated microfossil identification and segmentation. A pipeline is proposed that begins with scanning and ends with the microfossil segmentation process. For the microfossil segmentation, a Deep Learning approach was developed, which resulted in a high rate of correct microfossil segmentation (98% IOU). The validation was performed both through an automated quantitative analysis and visual inspection. The study was performed on a limited dataset, but the results provide evidence that our approach has potential to be generalized to other carbonatic rock substrates. To the extent of the authors' knowledge, this paper presents the first fully annotated MicroCT acquired microfossils dataset made publicly available.

Biostratigraphic results obtained with a systematic study of the planktic foraminiferal assemblages recovered from Upper Cretaceous-Lower Paleogene strata (Turonian? to early Danian in age) of Deep Sea Drilling Program (DSDP) Site 356, Sao Paulo Plateau, are presented and discussed herein. Fifty-nine planktic foraminiferal species were identifi ed within the studied interval, enabling the identifi cation of 11 planktic foraminiferal zones (Turonian? to early Danian in age): Marginotruncana schneegansi, Dicarinella concavata, Dicarinella asymetrica, Globotruncanita elevata, Contusotruncana plummerae, Radotruncana calcarata, Globotruncanella havanensis, Pseudoguembelina palpebra, Abathomphalus mayaroensis, Pseudoguembelina hariaensis and Pα. An unconformity spanning at least 0.96 Ma could also be suggested within core 31 (Maastrichtian in age), due to the absence of the Racemiguembelina fructicosa Interval Zone from the studied section. High sedimentation rates were estimated within the Santonian (Dicarinella asymentrica Total-range Zone) and the uppermost Maastrichtian (Pseudoguembelina hariaensis Interval Zone) of DSDP site 356, while lower and more constant values were suggested for the Campanian-lower Maastrichtian interval (Globotruncanita elevata Partial-range Zone to Pseudoguembelina palpebra Interval Zone). The reliability in identifying the Contusotruncana plummerae Interval Zone (Campanian in age) in Cretaceous sections of the South Atlantic Ocean is confi rmed herein.

OBJETIVO: Analisar as características cirúrgicas de pacientes operados após a intervenção coronária percutânea (ICP). MÉTODO: Cinqüenta e seis pacientes (41 H e 15 M), no momento da revascularização cirúrgica do miocárdio, já tinham sido manejados com o implante de stents coronarianos. Foram implantados 116 stents em 101 intervenções. Trinta e dois pacientes tinham três ou mais vasos com estenose significativa. Seis pacientes com lesões graves no tronco da artéria coronária esquerda (TCE) foram tratados com stents. Desde a colocação do primeiro stent, 12 pacientes desenvolveram lesões de novo graves no TCE. Em seis (50%), a estenose grave se desenvolveu em até seis meses da colocação do stent. Vinte (35,7%) pacientes eram diabéticos. Em 22 (39,2%) doentes, no momento da cirurgia, havia diminuição significativa da fração de ejeção do VE (p< 0,001), quando comparada à da primeira ICP. A revascularização cirúrgica constou do implante de 160 enxertos coronarianos. A análise transoperatória incluiu biópsia da parede coronária e do músculo adjacente. RESULTADOS: Achados transoperatórios evidenciaram tecidos adjacentes à área do stent mais endurecidos e inflamados quando comparados a outros sítios coronarianos. Dezessete pacientes operados sem descontinuidade dos antiadesivos plaquetários necessitaram de maior reposição sangüínea. Não houve mortalidade hospitalar pós-cirúrgica. CONCLUSÃO: Nos pacientes operados após a colocação de stents, questões como perda da função ventricular, arterite ou lesões de novo adicionam complexidade ao ato cirúrgico. Em razão da disfunção endotelial causada pelos stents, enxertos poderão ocluir mais cedo. Em adição, a eficiência do tratamento clínico associado poderá não ser a mesma.