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The record of marine ingression in western Gondwana from Devonian conodonts in the Amazonas and Solimões basins, Brazil Mar. Micropaleontol. (IF 1.9) Pub Date : 2024-02-23 Jordana Maria Viccari, Sara Nascimento, Ana Karina Scomazzon, Amanda Pericolo da Rosa, Andrés Felipe Rojas Mantilla, Sanmya Karolyne Rodrigues Dias, Paulo A. Souza, Valesca Brasil Lemos, Danielle Dall Amaria Soffiatti, Martín Andrés León Caffroni
During the Devonian, the Gondwana supercontinent was in a paleogeographic position in high-latitudes, close to the South Pole. The arrangement of continents, tectonic activity, climate fluctuations, and the evolution of marine life played an important role in the marine ecosystems during this period. Conodont occurrences in high-latitudes are scarce. In the Upper Devonian (Frasnian/Famenian) of western
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Unravelling the distribution of three Ammonia species (Foraminifera, Rhizaria) in French Atlantic Coast estuaries using morphological and metabarcoding approaches Mar. Micropaleontol. (IF 1.9) Pub Date : 2024-02-22 Marie P.A. Fouet, Magali Schweizer, David Singer, Julien Richirt, Sophie Quinchard, Frans J. Jorissen
Assessing the distribution of species in natural environments is essential for their use in environmental surveys. Here, we investigate the distribution of three pseudo-cryptic species formerly lumped in the morphospecies (Cushman, 1926) commonly found on estuarine mudflats along the European coasts: Schultze, 1854 (T1), Haynes, 1973 (T2) and Zheng, 1978 (T6). We studied their distribution at 51 sites
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Relative abundance and biometry of Bolivina ordinaria on the northern continental slope of the Pelotas basin during the late quaternary Mar. Micropaleontol. (IF 1.9) Pub Date : 2024-02-22 Patrícia Tortora Kother, Maria Alejandra Gomez Pivel, Kalina Manabe Brauko, Carla Bonetti
This study examines the variations in relative abundance, test size, and biomass of the species (Foraminifera) over the last 112 ka BP on the northern slope of the Pelotas Basin, Southern Brazil. The analyses were based on 651 individuals from 42 samples distributed along the cores SIS-249 (Marine Isotope Stage 5 to 3) and SIS-188 (Marine Isotope Stage 3 to 1). was the most abundant species of the
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Spatial and vertical distribution of the genus Amphistegina and its relationship with the indigenous benthic foraminiferal assemblages in the Pelagian Archipelago (Central Mediterranean Sea) Mar. Micropaleontol. (IF 1.9) Pub Date : 2024-02-07 Claudia Cosentino, Roberta Guastella, Nicoletta Mancin, Antonio Caruso
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Morphometric changes in Watznaueria barnesiae across the mid Cretaceous: Paleoecological implications Mar. Micropaleontol. (IF 1.9) Pub Date : 2024-02-06 Chiara Bettoni, Elisabetta Erba, Silvia Castiglione, Pasquale Raia, Cinzia Bottini
This study reveals moderate yet important variations in coccolith and central unit size throughout the Aptian–late Cenomanian (27 my) time interval in western Tethys. A new statistical approach was applied to determine whether non-random size trends apply to these metrics and to identify possible links between their variation and fertility or temperature. During OAE 1a, coccoliths were the smallest
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Paleoecology of selected Danian marine ostracods, geochemically pre-characterized by analysis of stable carbon (δ13C) and oxygen (δ18O) isotopes Mar. Micropaleontol. (IF 1.9) Pub Date : 2024-02-01 Marlone H.H. Bom, Daiane Ceolin, Karlos G.D. Kochhann, Rodrigo Do Monte Guerra, Guilherme Krahl, German Patarroyo, Mírian L.F.A. Pacheco, Lucas V. Oliveira, Telma Musso, Andrea Concheyro, Gerson Fauth
The Cerro Azul Section provides a continuous record of the Cretaceous-Paleogene (K-Pg) transition in a shallow marine context of the South Atlantic Ocean in the Neuquén Basin. Ostracod assemblages were severely affected by environmental changes across the event. Excellent ostracod preservation at the Cerro Azul Section allows to infer paleoecological preferences of four Danian species based on carbon
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Humid climate phases on the Island of Rhodes (Greece) during the late Pliocene at times of sapropel formation Mar. Micropaleontol. (IF 1.9) Pub Date : 2024-01-21 Daniela Eichner, Gerhard Schmiedl, Jürgen Titschack, Malu Ferreira, Maria Triantaphyllou, Nils Andersen, Yvonne Milker
The Island of Rhodes, located in the Eastern Mediterranean Sea, is affected by an active convergent plate boundary. In this context, marine sediments of Plio-Pleistocene age have been uplifted and are outcropping along the eastern coast of Rhodes. These archives provide an excellent opportunity to unravel the hydrological and climatic changes of the region during the late Pliocene. Our results provide
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Paleoecological and paleobiogeographic implications of a seagrass-indicating foralgal skeletal assemblage: Retracing the Burdigalian Quilon Limestone (Kerala Basin, SW India) Mar. Micropaleontol. (IF 1.9) Pub Date : 2024-01-19 Suman Sarkar, Yogesh Pal Singh, Poonam Verma
Seagrasses are marine angiosperms documented in shallow-marine, soft bottom settings across the Cenozoic. They proliferated globally after their divergence from other alismatid monocots in the late Cretaceous followed by an adaptation to the marine environment. Detailed evaluation of seagrasses in the geological archives is of utmost importance to understand their responses to climatic and environmental
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Calcareous nannoplankton response to middle-late Eocene climate and sea-level changes in the SW Neo-Tethys Mar. Micropaleontol. (IF 1.9) Pub Date : 2024-01-12 Jihede Haj Messaoud, Nicolas Thibault, Mohammed H. Aljahdali, Chokri Yaich, Yang-Guang Gu
We investigate the response of calcareous nannoplankton to the middle-late Eocene transition in the SW Neo-Tethys and compare our data to published results from X-ray diffraction (XRD) analysis, element content from X-ray fluorescence (XRF) and the abundance of microfossils in the coarse fractions of the sediment. The nannofossil assemblage is mainly composed of Reticulofenestra spp. (avg. 44%), Sphenolithus
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Two new ceratioid cornucavate dinoflagellate cysts from the Upper Cretaceous, Gulf of Suez, Egypt Mar. Micropaleontol. (IF 1.9) Pub Date : 2024-01-08 Ali Soliman, Hamid Slimani, Somia Said
Diverse and well-preserved assemblages of organic-walled dinoflagellate cysts have been recovered from the Matulla Formation (Coniacian – Santonian), Gulf of Suez, Egypt. Among the abundant dinoflagellate cyst assemblages, the new species Odontochitina elbeialyi sp. nov. and Odontochitina ornata sp. nov. (Family Ceratiaceae) are described. The two new species are unique by having a granulate periphragm
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Integrated biostratigraphy of Upper Cretaceous deposits from an exceptional continental vertebrate-bearing marine section (Transylvanian Basin, Romania) provides new constraints on the advent of ‘dwarf dinosaur’ faunas in Eastern Europe Mar. Micropaleontol. (IF 1.9) Pub Date : 2024-01-06 R. Bălc, R. Bindiu-Haitonic, S.-A. Kövecsi, M. Vremir, M. Ducea, Z. Csiki-Sava, D. Ţabără, Ș. Vasile
The present paper outlines the results of a detailed study of calcareous nannofossils and small foraminifera made on Campanian marine deposits from the southwestern part of the Transylvanian Basin, Romania, part of the marine-to-continental transitional Petrești succession that yielded the oldest temporally well-constrained continental vertebrate remains in this area. These results are integrated with
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Corrigendum to “An endemic conodont fauna of Darriwilian (Middle Ordovician) age from the Santa Gertrudis Formation, southwestern Gondwanan margin and its paleobiogeographic relationships” [Marine Micropalaeontology volume 181 (2023) 1–21/Article Number 102241] Mar. Micropaleontol. (IF 1.9) Pub Date : 2024-01-03 Guillermo L. Albanesi, C. Rubén Monaldi, Christopher R. Barnes, Fernando J. Zeballo, Gladys Ortega
Abstract not available
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A new methodology for foraminifera extraction from cemented calcareous shelf sediments Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-12-29 Anna Arrigoni, Werner E. Piller, Gerald Auer
Choosing the most conservative technique to extract unequivocally identifiable foraminiferal tests is crucial to avoid biases in sedimentary sequence dating and paleoenvironmental interpretations. However, for problematic samples containing heavily encrusted specimens, the concentration and isolation of microfossils might be challenging. In this work, we analyzed Early-Middle Pleistocene samples from
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Biodiversity and evolutionary phases of Lochkovian (Lower Devonian) conodonts in the Pyrenees: A comparative study Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-12-25 José Ignacio Valenzuela-Ríos, Jau-Chyn Liao
This paper aims to evaluate the zone-by-zone changes in Lochkovian conodont biodiversity in the Pyrenees region and compare the results with previous studies. Additionally, the paper seeks to identify evolutionary phases within the Lochkovian. We analyse the stratigraphic range data from eight classical Pyrenean Lochkovian sections. A total of 48 taxa at the species level, primarily confined to the
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Foraminifera associated with macroalgae on tropical coastal sandstone reefs Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-12-23 Davy Barbosa Bérgamo, David Holanda de Oliveira, Edson Régis Tavares Pessoa Pinho de Vasconcelos, Nykon Craveiro, José Souto Rosa Filho
While they are extremely abundant and ecologically important, the epiphytic foraminifera of tropical reefs are still poorly known. The present study describes the foraminiferal assemblages associated with macroalgae on tropical reefs of the Brazilian coast. Samples of four species of macroalgae, two foliose (Padina antillarum and Ulva lactuca) and two corticated (Palisada perforata and Gelidiella acerosa)
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Origins and paleoclimatic and paleoceanographic significance of laminated sediments of middle Pleistocene age from the southern Bering Sea Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-12-14 Jonaotaro Onodera, Alan E.S. Kemp, Richard B. Pearce, Keiji Horikawa, Kozo Takahashi
Laminated diatomaceous sediments occur intermittently in the Bering Sea over the past 5 million years. A varve (annually deposited) origin for the laminae has been suggested, but there is currently no consensus. Here, we report results of a study of two laminated intervals dating from ∼528 ka and ∼ 782 ka from IODP Site U1340 on the Bowers Ridge. We combine conventional micropaleontological methods
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Calcification depth of pteropods in the Coral Sea using stable oxygen isotopes Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-12-11 Zirong Huang, Anran Chen, Horng-Sheng Mii, Mahyar Mohtadi, Stephan Steinke
Pteropods are marine holoplanktonic gastropods inhabiting epipelagic and mesopelagic waters with a wide distribution from tropical to polar regions. However, their ontogeny and calcification depth/habitat depth are not well understood. To this end, we analyzed the stable oxygen isotopic composition of five pteropod species (Diacavolinia angulata, Diacavolinia longirostris, Heliconoides inflatus, Limacina
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Reconstruction of the sedimentary environment of Nayband Bay during the last 1600 years; implications for relative sea level and climate change in Northern Persian Gulf Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-12-07 Mohammad Ali Hamzeh, Abdolmajid Naderi Beni, Hamid A.K. Lahijani, Ali Mehdinia, Vahid Aghadadashi, Emad Koochaknejad
This paper reconstructs the relative sea level (RSL) and palaeoclimate of the northern coasts of the Persian Gulf (PG) during the last 16 centuries using physiochemical and ecological proxies from a radiocarbon-dated sediment core from the Nayband Bay (NB) estuary. The results show that between 1600 and 1150 cal yr BP, the NB was a marine lagoon with high river discharge, indicated by low organic matter
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Holocene paleo-redox conditions in a microbial dolomitic lake using benthic foraminifera as bioindicators Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-11-26 Daniel François, Camila Areias, Nayara Dornelas, Luiz G.R. Sá-Valle, Anna Paula Soares Cruz, José Carlos Sícoli Seoane, Crisógono Vasconcelos, Nicolás M. Stríkis, Daniel Souza dos Santos, Adina Paytan, Cátia F. Barbosa
Brejo do Espinho coastal lake (LBE) is one of the few places in the world where dolomite [CaMg(CO3)2] is precipitating in the modern environment under microbially induced processes and low oxygen conditions. We use pore morphometry of the foraminifera Ammonia cf. A. veneta to evaluate paleo-O2 dynamics during the dolomitic depositional phase that took place at LBE in the late Holocene. Foraminiferal
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Conodonts paleobiogeographic dynamic of the Pennsylvanian epicontinental sea Itaituba-Piauí, in the northern intracratonic Brazilian basins, Western Gondwana Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-11-20 Sanmya Karolyne Rodrigues Dias, Andrés Felipe Rojas Mantilla, Martín Andrés Leon Caffroni, Ana Karina Scomazzon, Sara Nascimento, Amanda Pericolo da Rosa, Renato Sol Paiva de Medeiros, Paulo A. Souza, Afonso César Rodrigues Nogueira, Jordana Maria Viccari
During the Pennsylvanian, icehouse glacioeustasy and the debasement of Western Gondwana caused widespread transgressive-regressive cycles in the Itaituba-Piauí epicontinental sea located in modern-day South America. This seaway extended from the most distal and western Solimões basin, into the medial Amazonas basin, and at times into the most eastern and restricted Parnaíba basin. These basins contain
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Origin and evolution of the Neogene calcareous nannofossil Ceratolithus Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-11-18 Carlos Lancis, José-Enrique Tent-Manclús, José-Abel Flores
Sediment samples of deep marine oceanic ODP boreholes from sites 999 in the Caribbean Sea and 1237 in the Eastern Pacific Ocean covering the period between 6 and 4.5 Ma have been studied with a focus on ceratolith evolution. Orthorhabdus rugosus is a nannolith with three blades (sinistral, median, and dextral) that first appeared during the Serravallian, it is not-birefringent in its stable orientation
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Local hydrodynamic in coastal system affects the coccolithophore community at a short spatial scale Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-11-15 Marina Addante, Michael Grelaud, Gerald Langer, Patrizia Maiorano, Sergio Bonomo, Marta Álvarez, Roberta Johnson, Patrizia Ziveri
Coccolithophores are an ecologically and biogeochemically important group of calcifying marine plankton, contributing globally to both the organic carbon pump and the carbonate counter pump. Understanding their distribution in today's ecosystems is crucial for both paleoenvironmental reconstruction and for predicting their fate under climate change and environmental pollution. Traditionally regarded
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The origin and significance of euhedral apatite crystals on conodonts Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-11-11 Daniele Malferrari, Annalisa Ferretti, Luca Medici
Crystal overgrowth on fossil remains is well-documented in the literature. Attention has specifically focused on bioapatite (i.e., an apatite of biochemical origin regardless of post-mortem changes) configurations, in order to decipher any possible relation to fossilization/diagenesis. This study investigates the Rare Earth Element (REE) and other High-Field-Strength Element (HFSE) composition of euhedral
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Significance of conodont data for explaining geosystem perturbations during the Middle Devonian Kačák Episode Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-10-21 Katarzyna Narkiewicz, Marek Narkiewicz, Alicja Wudarska
The present review of published data as well as the new results demonstrate the versatility of conodonts in documenting and explaining global environmental fluctuations related to the Kačák Episode (KE) in the latest Eifelian. Although the conodont zonation of the KE interval is ambiguous and requires revision, the compilation of conodont stratigraphic ranges shows their potential for a precise worldwide
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Paleocene–Eocene boundary in the Gabal El-Gir, east Qena, Egypt: Paleoenvironment and sequence stratigraphy interpretations Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-10-18 Islam El-Sheikh, Kamel H. Mahfouz, Abdullah O. Al-Ameer, Amr A. Metwally
Comprehensive field, litho-, biostratigraphy, and paleoenvironmental studies of the upper Paleocene–lower Eocene (P–E) boundary interval in the Gabal El-Gir area were conducted. Two selected sections El-Gir-1 and El-Gir-2 were investigated. The prevailed paleoenvironmental conditions were discussed in the frame of the nannofossils, planktonic, and benthic foraminiferal assemblages. Benthic foraminifera
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Merging databases for CNN image recognition, increasing bias or improving results? Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-10-11 Martin Tetard, Veronica Carlsson, Mathias Meunier, Taniel Danelian
Automated microscopy, image processing, and recognition using artificial intelligence is getting a growing interest from the scientific community, as more and more research centres are actively working on building datasets of images for training convolutional neural networks (CNNs) to identify microscopic objects. However, images acquired between institutes might show differences in light and contrast
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The biphasic life cycle of the non-spinose planktonic foraminifera is characterised by an aberrant coiling signature Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-10-02 Kate F. Darling, Katrine Husum, Isabel S. Fenton
The complete lifecycle of the planktonic foraminifera has continued to remain obscure. Benthic foraminifera exhibit an obligate alternation of generations between haploid gamonts and diploid agamonts, yet despite years of observation, the fusion of gametes to form a zygote, gamont or agamont has never been observed in the planktonic groups. Recent evidence from Neogloboquadrina pachyderma culture confirms
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Model of phylomorphogeny of P1 elements of the Tournaisian (Mississippian) siphonodellids Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-09-23 Artem N. Plotitsyn, Andrey V. Zhuravlev
Conodonts are a group of extinct marine organisms widely used in Paleozoic and Triassic biostratigraphy. The genus Siphonodella comprises ozarkodinid conodonts from the latest Famennian to the middle Tournaisian. The phylogenetic model of this genus plays an important role in biostratigraphy. This study is based on the authors' and published data on 31 species of siphonodellids of cosmopolitan and
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Morphometrics and machine learning discrimination of the middle Eocene radiolarian species Podocyrtis chalara, Podocyrtis goetheana and their morphological intermediates Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-09-18 Francisco Pinto, Veronica Carlsson, Mathias Meunier, Bert Van Bocxlaer, Hammouda Elbez, Marie Cueille, Pierre Boulet, Taniel Danelian
We present various approaches to distinguish the middle Eocene species Podocyrtis chalara and Podocyrtis goetheana, which are end members of a trajectory of phenotypic change, and their intermediate morphogroups. We constructed a set of thirteen traditional morphological variables to classify the entire morphological variability encompassed by the two morphospecies and their intermediates Podocyrtis
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Shape diversity in conodont elements, a quantitative study using 3D topography Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-09-16 Alexandre Assemat, Ghislain Thiery, Thibaud Lieffroy, Catherine Girard
The flourishment of conodont diversity through the Paleozoic is evidenced by the strong diversification of the shape of the elements composing their feeding apparatus. Among the different elements that compose the feeding apparatus, the platform elements (P1) are the most robust. However, the P1 elements also represent the most posterior dental elements of the apparatus, performing therefore the ultimate
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Integrated statistical analysis of calcareous nannofossil and elemental geochemistry of an outcrop from of the eastern Cenomanian Western Interior Seaway: Novel insights of shallow marine paleoceanography and nannoplankton paleoecology Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-09-06 Jonathan D. Schueth, Kelly Johnson
Phytoplankton assemblages in shallow marine environments are being impacted by anthropogenic climate change, but long-term outcomes of these changes are uncertain. Investigation of past neritic calcareous nannoplankton can help us understand the fate these ecosystems face. In this study, a Canonical Correspondence Analysis (CCA) of calcareous nannofossils and X-ray fluorescence geochemistry was used
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Conodont size in time and space: Beyond the temperature-size rule Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-09-07 Catherine Girard, Anne-Lise Charruault, Anne-Béatrice Dufour, Sabrina Renaud
The temperature-size rule (TSR) states that ectotherms mature at smaller adult body size in warmer conditions. Such a rule may have the potential to explain size response of fossil organisms to past temperature variations, but its validity in deep time has been seldom tested. The generality of this rule was investigated here by compiling data documenting the size record of three conodont genera (Palmatolepis
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Distribution of modern benthic foraminiferal assemblages across the Northeast Greenland continental shelf Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-08-20 Joanna Davies, Jeremy Lloyd, Christof Pearce, Marit-Solveig Seidenkrantz
Analysis of benthic foraminifera in surface samples from 23 sites on the Northeast Greenland continental shelf reveal key assemblage differences between sites. Cluster analysis creates two clear geographical faunal assemblage zones: the 1) inner shelf, and 2) mid and outer shelf sites. These assemblages differ significantly, with the inner shelf sites being characterised by a high percentage and concentration
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No dramatic changes observed in subtropical radiolarian plankton assemblages during the Middle Eocene Climatic Optimum (MECO); evidence from the North Atlantic ODP Site 1051 Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-08-16 Mathias Meunier, Taniel Danelian
The Middle Eocene Climatic Optimum (MECO; ca. 40 Ma) was a prominent global warming event that lasted 400 kyr and was characterized by a 4–6 °C rise in high latitude surface and deep-water temperatures. As the radiolarian plankton response to this warming event is practically unknown, whole assemblage quantitative analyses were undertaken on well-preserved radiolarian assemblages from ODP Site 1051
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Variations in benthic foraminifera biofacies since Mid-Pleistocene (MIS 7) in the Campos Basin slope, Eastern Brazil: Assessing present-day and past controlling factors Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-08-03 Sarah Pereira Gasparini, Claudia Gutterres Vilela, Mark Maslin, Kimmolly Ferrari Ferreira
Benthic and planktonic foraminifera faunal and stable isotopic (δ18O and δ13C) analyses on foraminiferal tests were carried out on a piston core, collected from the Campos Basin slope at a water depth of 1475 m. The core location is in front of Cape São Tomé and exhibits landslide scars features. Benthic foraminifera biofacies with ecological indexes and statistics, lithological facies, biostratigraphy
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Pseudofurnishius (Conodonta) from the Triassic Drežnica section, Bosnia and Herzegovina Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-08-01 Tea Kolar-Jurkovšek, Carlos Martínez-Pêrez, Hazim Hrvatović, Dunja Aljinović, Špela Goričan, Ferid Skopljak, Bogdan Jurkovšek
Triassic strata in the Drežnica section, Bosnia and Herzegovina have been examined biostratigraphically. The limestone and dolostone strata were deposited in deep pelagic environment. The conodont faunas are marked by prevailing elements of the genus Pseudofurnishius including clusters that enabled to distinguish the huddlei (lower Longobardian) and murcianus (upper Longobardian–?Cordevolian) Zones
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Origin and evolution of the Early Ordovician conodont genus Prioniodus Pander, 1856 — New evidence from South China Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-07-26 Yong Yi Zhen, Yuan-Dong Zhang, Zhong-Yang Chen, Long-Wu Wang
A conodont fauna of late Tremadocian to early Floian age (Early Ordovician) is documented from the Yinchufu Formation of Zhejiang Province, South China. It is characterized by the occurrence of two species of Prioniodontidae, a new species of Prioniodus and Acodus triangularis. Prioniodus antiquus sp. nov. may represent the most primitive species of Prioniodus, which is one of the earliest conodont
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Convolutional neural network application on a new middle Eocene radiolarian dataset Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-07-18 Veronica Carlsson, Taniel Danelian, Martin Tetard, Mathias Meunier, Pierre Boulet, Philippe Devienne, Sandra Ventalon
A new radiolarian image database was used to train a Convolutional Neural Network (CNN) for automatic image classification. The focus was on 39 commonly occurring nassellarian species, which are important for biostratigraphy. The database consisted of tropical radiolarian assemblages from 129 middle Eocene samples retrieved from ODP Holes 1258A, 1259A, and 1260A (Demerara Rise). A total of 116 taxonomic
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Seasonal Mg/Ca-inferred temperatures of brackish water ostracods Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-06-25 L.R. Roberts, J.A. Holmes
The common brackish water ostracods Cyprideis torosa and Loxoconcha elliptica frequently occur together in high abundances in marginal marine environments. Seasonality of calcification differs between species and can have important implications for palaeotemperature reconstructions. There are existing palaeotemperature calibrations for both genera. However, the Loxoconcha spp. Mg/Ca temperature calibration
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Appraisal of middle Floian (Lower Ordovician) conodont diversity of the Precordillera and Cordillera Oriental, Argentina: Paleobiogeographical implications Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-06-16 E. Kristal Rueda, Guillermo L. Albanesi
In this paper we compare the diversity of Floian (Lower Ordovician) conodonts from the Precordillera with that of the Cordillera Oriental, Argentina. The comparative analysis is restricted to the middle Floian Stage Slice (Fl2) from correlative intervals: Oepikodus evae Zone (Juanognathus variabilis Subzone) in the Precordillera and the Gothodus andinus Zone in the Cordillera Oriental. For the comparative
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To be or not to be a conodont. The controversial story of Pseudooneotodus and Eurytholia Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-06-13 Annalisa Ferretti, Carlo Corradini, Sana Fakir, Daniele Malferrari, Luca Medici
The genus Pseudooneotodus (Drygant, 1974) is a genus of small and conical elements widely distributed from the Middle Ordovician to the Early Devonian throughout the world. Because of its unusual shape, Pseudooneotodus has long been considered enigmatic, and only in the late nineties of the last century the genus has been finally placed within conodonts according to histological data. This study investigates
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Graphical methods comparing living and dead assemblages, exemplified with benthic foraminifera from the Aveiro Lagoon, Portugal Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-06-09 J. Hohenegger, M.V.A. Martins, W. Eder, T.M. Senez-Mello, F.L. Damasceno, L. Laut
This work introduces graphical methods documenting density, diversity (species richness combined with heterogeneity) and similarity in combined diagrams for estimating the influence of environmental and taphonomic factors in living (LAs) and dead (DAs) assemblages. In this paper, the diagrams compare: 1) densities per 1 g of sediment expressed in cubic squares; 2) diversities based on rarefaction species
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Foraminiferal assemblages from the Abu Qir coastal area (Alexandria, Egypt): Wave-cut platform versus shallow-bay sediments Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-05-26 Ahmed Mohamed BadrElDin, Pamela Hallock
Benthic foraminifers living in euphotic coastal and shelf environments commonly occur in association with macrophytes (macroalgae and seagrasses), and many lineages have evolved morphologic adaptations to thrive in such habitats. Species that did not occur in the Mediterranean Sea prior to recent centuries, commonly known as “introduced” or “alien” species, are now widespread, and some are so abundant
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Benthic foraminiferal morphogroups and their response to relative sea-level changes in the upper Hauterivian-lower Barremian Agua de la Mula Member of the Agrio Formation (Patagonia, Argentina) Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-05-18 M. Caratelli, F. Archuby
A morphogroup analysis of the upper Hauterivian-lower Barremian foraminiferal assemblages from the Agua de la Mula Member of the Agrio Formation (Neuquén Basin, Argentina) reveled six associations based on benthic foraminiferal morphogroups identified by means of cluster analysis and treated with multivariate methods. In order to assess the paleoenvironmental significance of the morphogroup associations
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Threads of microbial activity on quasi-anoxic environments: Case studies from Oligocene to Miocene of the Central Paratethys Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-05-02 Marta Kerkhoff, Katarína Holcová, Katalin Báldi, Natália Hudáčková, Martin Racek, Jakub Trubač, Adam Culka
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Foraminifera in temperate fjords strongly affected by glacial meltwater, Tierra del Fuego, South America Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-05-02 Sergei Korsun, Olga Kniazeva, Wojciech Majewski, Maria Angelica Godoi, Tatiana Hromic, Marina Varfolomeeva, Jan Pawlowski
Chilean Patagonia is one of the few regions in the Southern Hemisphere where tidewater glaciers deliver torrential meltwater. We sampled the Beagle Channel and five tributary fjords, with and without glaciers, to explore modern foraminifera of this little studied region. Surface sediments (mud, sand, pebbles, and shell debris) were collected at 45 stations from water depths 15 to 250 m, along with
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Early Cretaceous monsoonal upwelling along the northern margin of the Gondwana continent: Evidence from radiolarian cherts Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-04-29 Xiaohui Cui, Xin Li, Jonathan C. Aitchison, Hui Luo
Radiolarian-bearing cherts are widely exposed in the volcanic-sedimentary sequences associated with the Purang ophiolitic mélange in the western segment of the Yarlung Tsangpo suture zone. Highly diverse and well preserved Lower Cretaceous (Valanginian–Hauterivian) radiolarian assemblages that correlate to the Cecrops septemporatus Zone occur in bedded cherts in the Peiersanggangmu section of the southern
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Synergic role of frontal migration and silicic acid concentration in driving diatom productivity in the Indian sector of the Southern Ocean over the past 350 ka Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-04-11 Sunil Kumar Shukla, Xavier Crosta, Minoru Ikehara
The glacial-interglacial siliceous productivity in the Sub-Antarctic Zone (SAZ) of the Southern Ocean (SO) has been proposed to respond to higher dust-bearing iron fluxes and/or basin-wide increased nutrient supply to surface waters. However, long records of diatom productivity are mainly obtained from the Atlantic and Pacific sectors of the SO. We present a new diatom productivity record from the
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Implication of middle Eocene to early Miocene ostracodes from the N. El Faras-1X Well, Qattara Depression, Egypt, for paleobathymetry and paleobiogeographic reconstruction Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-04-14 Abdalla Shahin, Samar El Khawagah, Banan Shahin
The subsurface middle Eocene - early Miocene succession in the N. El Faras - 1X Well, drilled in the Qattara Depression at the northern part of the Western Desert, Egypt (Southern Tethyan Province, STP), was studied for its ostracode content to infer changes in paleobathymetry as well as paleobiogeographic reconstructions. This succession is composed mainly of three lithostratigraphic units, as the
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Middle Miocene final demise of remnants of an eastern Neotethyan seaway, Naga Hills, Indo-Myanmar Range Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-03-31 Kapesa Lokho, Jonathan C. Aitchison, Ankit Kumar, Renjie Zhou, Muthusamy Prakasam, D.S.N. Raju
Miocene planktonic foraminifers occur in shale intercalated with thinly bedded siltstone and sandstone of the Surma Group in the foothills of the Naga Schuppen Belt of the Indo-Myanmar Range. Fourteen species from eleven genera are the first clearly imaged middle Miocene foraminifers recorded from the Surma Group in the Naga Hills. This new M5-M6 assemblage from the upper unit of the Bhuban Formation
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Implication of size fraction on benthic foraminiferal-based paleo-reconstructions: A case study from the Bay of Biscay (NE Atlantic) Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-03-30 Pauline Depuydt, Christine Barras, Samuel Toucanne, Eleonora Fossile, Meryem Mojtahid
Many paleoenvironmental studies based on benthic foraminiferal assemblages use different protocols for sample analysis. A standardized protocol has been recently established for biomonitoring applications, but for paleostudies, the influence of size fraction on benthic foraminiferal composition and biodiversity is poorly documented. We studied fossil foraminiferal assemblages along two paleorecords
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An endemic conodont fauna of Darriwilian (Middle Ordovician) age from the Santa Gertrudis Formation, southwestern Gondwanan margin and its paleobiogeographic relationships Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-03-30 Guillermo L. Albanesi, C. Rubén Monaldi, Christopher R. Barnes, Fernando J. Zeballo, Gladys Ortega
A large collection of conodonts (over 4200 elements) from the Santa Gertrudis Formation of the Cordillera Oriental, NW Argentina, is analyzed. The mostly endemic fauna of this unit and the lack of index species require complex taxonomic and biostratigraphic interpretations. We determined new species apparatuses by reviewing previous literature with a different taxonomic approach: Erismodus saltaensis
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Constant shell density of hyaline large benthic foraminifers under thermal stress Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-03-21 Shunichi Kinoshita, Azumi Kuroyanagi, Hodaka Kawahata, Kazuhiko Fujita, Toyoho Ishimura, Atsushi Suzuki, Harumasa Kano, Yoshimi Kubota, Hiroshi Nishi
Recently, increased concentrations of anthropogenic atmospheric CO2 have caused ocean warming and acidification, leading to swift environmental alterations. In coral reef regions, bleaching and death of symbiotic calcifying organisms have been distressing. Generally, large benthic foraminifers (LBF), a principal symbiotic calcifying organisms in coral reefs, have gained popularity because thermal stress
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The Miocene Climatic Optimum at the interface of epicontinental sea and large continent: A case study from the Middle Miocene of the Eastern Paratethys Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-03-15 Yuliia V. Vernyhorova, Katarína Holcová, Nela Doláková, Bettina Reichenbacher, Filip Scheiner, Lukáš Ackerman, Jan Rejšek, Lorenzo De Bortoli, Jakub Trubač, Torsten Utescher
The Miocene Climate Optimum (MCO) and the subsequent Miocene Climate Transition (MCT) are important biotic, environmental and geologic events. Here we address whether this holds true for the epicontinental Eastern Paratethys Sea (today's Black – Caspian Sea region). Two Tarkhanian – lower Chokrakian sequences of Middle Miocene age in the Kerch Peninsula were investigated using foraminifera, calcareous
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Holocene sea surface temperature and salinity variations in the central South China Sea Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-03-10 Jun Yang, Yanyan Zhao, Haotian Wei, Sheng Liu, Guanglu Zhang, Haiyan Long, Sanzhong Li, Jishang Xu
The South China Sea (SCS) is sensitive to the East Asian monsoon (EAM) and changes in the Western Pacific. However, because of the difficulty of sampling and lack of data in the central SCS, many uncertainties remain the primary driving force of paleoclimatic variations. Here, a sediment core JL136, from the central SCS, was used to evaluate variations of sea surface temperature (SST) and salinity
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Northward migration of the maximum Indian summer monsoon precipitation during the early–mid-Holocene: Evidence from sporopollen in the Andaman Sea Mar. Micropaleontol. (IF 1.9) Pub Date : 2023-03-10 Zijie Yang, Chuanxiu Luo, G.M. Ariful Islam, Xuhui Dong, Xiang Su, Rong Xiang, Shuhuan Du, Yiping Yang, Shengfa Liu
The Indian summer monsoon (ISM) significantly influences the evolution of the natural environment and the development of human societies in South Asia, however, the spatiotemporal nature of the maximum ISM precipitation remains uncertain. We present the first sedimentary sporopollen record from core ADM-C1 in the southern Andaman Sea, covering the past 11.2 ka to better understand the evolutionary