Marine Micropaleontology最新文献

{"title":"Abundance of Liquidambar during MIS 5 indicates a significantly warmer climate than MIS 1 along the South Yellow Sea coast","authors":"Jie Li ,&nbsp;Zhaofeng Gu ,&nbsp;Zhenhe Wen ,&nbsp;Shixiong Yang ,&nbsp;Gayan Bandara ,&nbsp;Baojun Wang ,&nbsp;Xi Mei ,&nbsp;Chuanxiu Luo ,&nbsp;Yachao Qin","doi":"10.1016/j.marmicro.2026.102577","DOIUrl":"10.1016/j.marmicro.2026.102577","url":null,"abstract":"<div><div>The relative warmth of different interglacial periods provides crucial insights into climate system sensitivity under varying boundary conditions. While global proxy records indicate that the Last Interglacial (MIS 5, specifically MIS 5e) was warmer than the present Holocene (MIS 1), quantitative terrestrial evidence from temperature-sensitive proxies in East Asia remains scarce. In this study we present a new high-resolution palynological record from core LYK-1 in the western South Yellow Sea (SYS), spanning from MIS 5 to the present, to quantitatively assess the relative warmth of these two interglacials. We utilize the pollen of <em>Liquidambar</em>, a thermophilous genus with stringent climatic requirements, as a key temperature proxy. By integrating pollen data with robust lithological, foraminiferal, and chronological controls, we first disentangle the influences of sea-level change and depositional environment on the pollen assemblages to isolate the climatic signal. By further comparison with the surrounding records, the results reveal a striking contrast: <em>Liquidambar</em> pollen is significantly more abundant during MIS 5 than MIS 1. This indicates that the MIS 5e climate along the SYS coast was substantially warmer and more humid than the Holocene, allowing for a notable northward expansion of subtropical flora. The herbaceous pollen dominance throughout the core is interpreted as a signature of fluvial transport dynamics in this inner-shelf setting rather than a purely open landscape. This well-dated record provides robust terrestrial evidence for a significantly warmer MIS 5 in East Asia, underscoring the region's sensitivity to interglacial intensity and offering a valuable paleo-analogue for understanding future warming scenarios.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"204 ","pages":"Article 102577"},"PeriodicalIF":1.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147849502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Holocene coastal sedimentary evolution of the southern Taihu Plain, East China","authors":"Yuhai Wang ,&nbsp;Bing Song ,&nbsp;Deke Xu ,&nbsp;Yulong Niu ,&nbsp;Peng Qian ,&nbsp;Ting Chen ,&nbsp;Ye Yang ,&nbsp;Feng Wang ,&nbsp;Jun Kuang ,&nbsp;Hao Li ,&nbsp;Chang Li ,&nbsp;Jiatong Lü ,&nbsp;Jie Liu ,&nbsp;Houyuan Lü ,&nbsp;Xiangdong Yang","doi":"10.1016/j.marmicro.2026.102578","DOIUrl":"10.1016/j.marmicro.2026.102578","url":null,"abstract":"<div><div>The formation and evolution of the Taihu Plain during the Holocene have significantly influenced the development of Neolithic cultures in the region. Based on AMS ¹⁴C dating, lithological analyses of cores SZ24 and SZ50, and pollen analyses of core SZ24, and supplemented with previous results from cores SE2 and JLQ, this study reconstructs the Holocene depositional history of the southern Taihu coastal zone. The Late Pleistocene surface represented an ancient plain incised by palaeo-valleys near the Qiantang River. Holocene sediments overlie this substrate and record a transgressive estuarine environment during the early Holocene, followed by plain progradation during a relatively slow rise and gradual stabilization of mid-Holocene sea-level. After ∼7.0–5.7 cal kyr BP, the southern Taihu Plain gradually emerged, forming the modern landscape. The sedimentary processes differ from those of larger estuaries in East Asia during the middle to late Holocene, possibly due to the absence of a large river discharging into the palaeo-estuary.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"204 ","pages":"Article 102578"},"PeriodicalIF":1.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147849503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dinoflagellate cysts in sediment traps from the Nordic Seas: Implications for their use as proxies in paleoceanography","authors":"Amy L. Dale ,&nbsp;Barrie Dale","doi":"10.1016/j.marmicro.2026.102554","DOIUrl":"10.1016/j.marmicro.2026.102554","url":null,"abstract":"<div><div>The Nordic seas are important for bottom water formation and heat transfer in global climate, and dinoflagellate cysts are a major microfossil group in cored sediments from high latitudes where mineralized fossils are absent due to dissolution. This first basin-wide study of dinoflagellate cysts in deep-sea sediment traps reassesses the basic assumptions of paleoceanographic proxies: that dinoflagellate cysts in bottom sediments represent primary environmental signals from overlying surface waters carried by cysts sinking without significant lateral transport. We studied 126 samples collected at 12–30 day intervals over one year from traps (approximately 400 m above bottom) at 9 stations. We recorded 27 cyst taxa quantitatively (cyst fluxes) and as assemblages calculated from the fluxes. Correspondence analysis was used to compare cyst assemblages from traps with those in recent bottom sediments used to create proxies. The generally high correlation shown between fluxes of cysts and lithogenic particles suggests common transport mechanisms for both. We show three different sources of cysts and environmental signals: primary, from oceanic surface waters; secondary, transported in from shallow adjoining waters and ocean currents; and tertiary, older cysts resuspended from shelves. We found poor correspondence between cysts in traps and those in bottom sediments mainly due to the dominance of <em>O. centrocarpum</em> in the sediments, but correspondence analysis identified the main current regimes in both. We propose that <em>O. centrocarpum</em> here and elsewhere in oceanic sediments reflects an opportunistic response to mixing of oceanic/shelf waters. Consideration of factors highlighted here should help to improve the use of proxies.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"203 ","pages":"Article 102554"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gradual turnover in the composition of benthic foraminiferal assemblages across the Sinemurian/Pliensbachian boundary in the Transcarpathian Ukraine (Pieniny Klippen Belt, Eastern Carpathians)","authors":"Štefan Józsa ,&nbsp;Adam Tomašových ,&nbsp;Ján Schlögl ,&nbsp;Christian Meister ,&nbsp;Vladimír Šimo","doi":"10.1016/j.marmicro.2026.102551","DOIUrl":"10.1016/j.marmicro.2026.102551","url":null,"abstract":"<div><div>The Sinemurian/Pliensbachian boundary interval in the eastern part of the Pieniny Klippen Belt (Eastern Carpathians, Ukraine) is preserved in a succession formed by a marl-limestone alternation that was deposited in a low-energy, outer shelf environment on the NW margin of the Tethys shelf (Euroboreal Province). Assemblages with benthic foraminifers are diverse, with fifteen agglutinated species and 64 calcareous species. Although most species range across the Sinemurian/Pliensbachian boundary, the assemblages of agglutinated and calcareous benthic foraminifers exhibit a gradual and protracted change in abundance of species, genera, and functional morphogroups during this time interval. The increase in abundance of lenticular (C8) and elongated-flattened (C6) morphogroups and the decline in abundance of elongated morphogroups with a straight periphery (C8) across the boundary is gradual. This turnover in taxonomic and functional composition can be related to an increase in ventilation and bottom currents that decreased any incidences of oxygen depletion, reduced organic matter preservation, and allowed the onset of sponge biostromes during the earliest Pliensbachian. In contrast to stratigraphic changes in abundance of individual species, alpha species (mean = 21) and genus (mean = 11) diversity remains rather constant across the S/P boundary and the overall assemblage composition is persistently dominated by deposit-feeders and grazing omnivores both in the uppermost Sinemurian and the lowermost Pliensbachian. Therefore, although the overall shallowing-up trend in outer-shelf habitats contributed to directional changes in abundance of some species, genera and morphogroups, they did not induce any major turnover, extirpation or immigration at species or genus level.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"203 ","pages":"Article 102551"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increase the magnification, they are shrinking! Morphometric variations of the planktic foraminifera Globigerina bulloides in response to environmental changes over the last 27.4 ka in the Ligurian Sea","authors":"Pierluigi Martinelli ,&nbsp;Isabel Cacho ,&nbsp;Elena Cavallero ,&nbsp;Antonio Cascella ,&nbsp;Letizia Di Bella ,&nbsp;Fabrizio Lirer ,&nbsp;Mar Selvaggi ,&nbsp;Rocco Gennari","doi":"10.1016/j.marmicro.2026.102552","DOIUrl":"10.1016/j.marmicro.2026.102552","url":null,"abstract":"<div><div>This study investigates the test size variability of the planktic foraminifera <em>Globigerina bulloides</em> over the past 27.4 ka from sediment core NDT_22_2016, collected in the Ligurian Sea. This climatically sensitive region provides an ideal setting to explore how large-scale glacial-interglacial oscillations influenced the phenotypic plasticity of the non-symbiotic planktic foraminifer <em>G. bulloides</em> through changes in surface-water conditions.</div><div>We explore the relationships between test size and sea surface temperature (SST), relative salinity (δ¹⁸Osw-ivc), and atmospheric CO₂. To test this, over 3400 specimens from 110 samples were analysed. Morphometric data were obtained through high-resolution imaging and automated area measurements, while environmental variables were derived from Mg/Ca-based SST reconstructions and stable isotope analyses, both performed on <em>G. bulloides</em> tests, and from published ice core CO₂ records.</div><div>Descriptive statistics reveal a significant reduction in test size from the Pleistocene to the Holocene, with the largest specimens recorded during the Younger Dryas. Generalized linear mixed models (GLMMs) indicate that <em>G. bulloides</em> tests size responds significantly to environmental forcing: size decreases with increasing SST, consistent with Atkinson's temperature-size rule; increases (although less significantly) with increasing δ¹⁸Osw-ivc; and exhibits a non-linear (quadratic) relationship with CO₂. The occurrence of larger tests at lower temperatures and higher salinities could also be related to higher productivity in a paleoceanographic context that favoured water-column mixing and surface fertilization. To test the possible productivity-size relationship, we used the abundance of <em>G. bulloides</em> as a proxy for productivity, but no significant relationship was revealed by the GLMM.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"203 ","pages":"Article 102552"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Foraminiferal biostratigraphy, paleoenvironmental interpretation, and sequence stratigraphy of the latest Maastrichtian–Thanetian succession in the Southern Galala Plateau, Eastern Desert, Egypt","authors":"Aziz M. Abu Shama ,&nbsp;Sherif Farouk ,&nbsp;Ahmed Abdelwahhab ,&nbsp;Youssef S. Bazeen","doi":"10.1016/j.marmicro.2026.102555","DOIUrl":"10.1016/j.marmicro.2026.102555","url":null,"abstract":"<div><div>We present an integrated study of two stratigraphic sections from the Southern Galala Plateau that combines foraminiferal biostratigraphy with quantitative paleoenvironmental proxies and sequence stratigraphic analysis across the latest Maastrichtian–Thanetian interval. High-resolution planktic zonations (Maastrichtian CF2–CF1; Paleocene P1c–P4c) reveal variable temporal hiatuses at the Cretaceous/Paleogene (K/Pg) boundary, with an abrupt planktic foraminifera extinction, a low benthic foraminiferal extinction (∼9%), and drops in TFN, HOFS%, and paleodepth, followed by increased EBFOI, reflecting improved bottom water oxygenation in the Danian. The Latest Danian Event (LDE) is recorded only in South Wadi El-Maheer, characterized by brown nodular calcareous shale, high HOFS%, low EBFOI, a paleodepth drawdown, and the invasion of the <em>Neoeponides duwi</em> assemblage. The Danian/Selandian (D/S) boundary exhibits a pronounced sea-level fall, mirroring the global signal. Its placement varies between both sections due to differences in hiatus magnitude, which is greater in Wadi Ragela, as indicated by an abrupt planktic foraminiferal assemblage shift and the reduced thickness of P3a and P3b. The sequence stratigraphic analysis revealed seven third-order depositional sequences in Wadi Ragela and five in South Wadi El-Maheer. The proposed sequence stratigraphic framework confirms that the study area was influenced by eustatic changes and regional tectonic activities.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"203 ","pages":"Article 102555"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in pteropod assemblage driven by monsoonal variability and associated oceanographic conditions since the last Glacial Maximum in the eastern Arabian Sea","authors":"Jeet Majumder ,&nbsp;Anil K. Gupta ,&nbsp;Vipul Singh Rathaur","doi":"10.1016/j.marmicro.2026.102561","DOIUrl":"10.1016/j.marmicro.2026.102561","url":null,"abstract":"<div><div>We present a record of well preserved aragonitic shell bearing pteropods from core SK291/GC17, eastern Arabian Sea. The study is aimed to investigate the temporal changes in pteropod assemblage and their preservation state linked to changes in the surface condition driven by the Indian Summer Monsoon (ISM) from ∼25,000 to 3500 calibrated year before present (cal yr BP). <em>Heliconoides inflatus</em> (earlier known as <em>Limacina inflata</em>) is the most dominant pteropod species, followed by <em>Limacina trochiformis</em>, <em>Creseis</em> spp., <em>Limacina bulimoides</em>, and <em>Gleba cordata</em> as other important component of the pteropod assemblage. Pteropod shells show only a primary level of dissolution evident from low values of Limacina Dissolution Index (LDX) which ranges between 0.8 and 2.5. Milky white shells (LDX ∼2.5) of <em>H. inflatus</em> can be seen mainly during the middle to late Holocene, possibly due to influence of oxygen minimum zone water. Higher relative abundance and larger shell size of <em>H. inflatus</em> are positively correlated with the elevated surface productivity caused by ISM-induced upwelling in the Holocene. On the other hand, low abundance and smaller shells of <em>H. inflatus</em> are mostly found in the last glacial maximum (LGM) and 4.2 ka event. Other pteropod species such as L. <em>trochiformis, Creseis</em> spp.<em>, L. bulimoides,</em> and <em>G. cordata</em> seem to be less influenced by the surface productivity, and correlate more with the changes in sea surface temperature and salinity in the Eastern Arabian Sea.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"203 ","pages":"Article 102561"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Palynology of the Upper Triassic strata from Tabas, east-central Iran: Biostratigraphic, paleoenvironmental, and paleobiogeographic inferences","authors":"Freshteh Sajjadi Hezaveh ,&nbsp;Firoozeh Hashemi-Yazdi","doi":"10.1016/j.marmicro.2026.102558","DOIUrl":"10.1016/j.marmicro.2026.102558","url":null,"abstract":"<div><div>Subsurface data from Well no. 954, Tabas, east-central Iran, constitute the foundation for an integrated palynological, paleoenvironmental, and paleobiogeographical analysis of the Upper Triassic (Rhaetian) Qadir Member of the Nayband Formation. The assemblage consists of diverse, moderately preserved spores and pollen. Of the latter, such taxa as <em>Falcisporites nuthallensis</em>, <em>Lunatisporites rhaeticus</em>, <em>Ovalipollis ovalis</em>, <em>Ricciisporites tuberculatus</em>, and <em>Araucariacites australis</em> dominate the assemblages. Representatives of such trilete spores as <em>Dictyophyllidites mortonii, Gleicheiniidites senonicus Kyrtomisporis laevigatus</em>, <em>Limbosporites</em> spp., and <em>Lophotriletes bauhiniae</em>, are essentially abundant in the palynofloras examined. Vertical distribution of miospores allows recognition of <em>Dictyophyllidites-Striatella seebergensis-Ricciisporites tuberculatus</em> assemblage zone (Rhaetian). The inferred natural relationships of the <em>sporae dispersae</em> indicate a parental flora derived from, in descending order: Pterophyta, Cycadophyta, Pteridospermophyta, Coniferophyta, Lycopodophyta, Ginkgophyta, and Bryophyta. Fern abundance suggests a moist, warm climate. Sporomorph EcoGroup (SEG) analysis shows dominant lowland/plain communities over upland and coastal/tidal ones, indicating deposition during relatively low sea level in shallow marine conditions. Palynological analysis identifies three palynofacies following Tyson's methodology. Palynofacies I represents very proximal, shallow shelf environments during sea-level fall and regression. Palynofacies II suggests dysoxic to anoxic, restricted shallow-water settings. Palynofacies VI indicates conditions from low-oxygen coastal to anoxic shelf environments. Key proxies—the transparent/opaque AOM ratio, equidimensional/blade-shaped opaque phytoclasts (P1/P2) ratio, and terrestrial/marine (T/M) ratio—support this interpretation. The palynofloras show strong biogeographic affinities with both northern Gondwana and southern Laurasia, highlighting Iran's position as a biogeographic crossroads on the southern margin of Eurasia during the Late Triassic.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"203 ","pages":"Article 102558"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paleoenvironmental significance of Early Miocene coralline red algae from the Qom Formation, Central Iran","authors":"Suman Sarkar ,&nbsp;Mehdi Hadi ,&nbsp;Yaghub Nasiri ,&nbsp;Mohsen Allameh","doi":"10.1016/j.marmicro.2026.102556","DOIUrl":"10.1016/j.marmicro.2026.102556","url":null,"abstract":"<div><div>Understanding the evolution of shallow-marine biotic assemblages is not less important than deep-sea ecosystems in deciphering the climate dynamics of the Earth, yet attract lesser attention from the research community in terms of applied case studies. Representing a major shallow-marine biotic group, coralline red algae show very wide geographical distribution from tropics to the poles, and also have high potential as proxies in reconstruction of Cenozoic paleoenvironments. Here, Early Miocene coralline algae from a carbonate-dominated succession of the Qom Formation outcropping in Ghalibaf (central Iran) are evaluated to understand their paleoenvironmental affinities and significance. By referring to their qualitative assessment and relative abundance, coralline algal assemblages are used to interpret the depositional conditions. A depth range of 20–30 m is interpreted for the coralgal-foraminiferal facies based on the presence of abundant hermatypic corals and endosymbiont larger miliolid foraminifera with corallines pertaining to the orders Hapalidiales (<em>Mesophyllum</em>-dominant) and Corallinales. Conversely, the abundance of Hapalidiales (<em>Lithothamnion</em>-dominant) in association with smaller miliolids and poor quantities of Corallinales in the bryozoan-coralline algal (bryorhodalgal) and coralline algal (rhodalgal) skeletal associations relate to a deeper bathymetric range of 40–60 m. The environmental regime during the Early Miocene seems to have supported the growth and development of coralline algae in the Central Iran Basin.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"203 ","pages":"Article 102556"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sudden disappearance of the foraminifer Calcarina gaudichaudii in the boundary between the Southern and Central Kuroshio ecoregions in the Ryukyu Archipelago, Japan","authors":"Bryan Gabriel P. Tan ,&nbsp;Goushi Moribe ,&nbsp;Kazuhiko Fujita","doi":"10.1016/j.marmicro.2026.102559","DOIUrl":"10.1016/j.marmicro.2026.102559","url":null,"abstract":"<div><div>Ocean warming induces biogeographic range extension of coral reef-associated organisms toward higher latitudes. The Japanese Islands are one of the most suitable places to study the range extension. Biogeographic distributions of the Foraminiferal family Calcarinidae along the Ryukyu Archipelago (the Ryukyus), southwestern Japan, indicate a change in assemblage composition between the central and northern regions. To fully understand these changes near the boundary, we examined calcarinid assemblages in 36 surface sediments collected from a beach, shallow lagoon, and reef crest from the central (Amami Oshima) and the northern (Takara Jima and Kuchinoshima) regions. The results showed that of the 8 identified calcarinid species, <em>Baculogypsina sphaerulata</em> was found in all samples and dominant in the north, while <em>C. gaudichaudii</em> was the most common in Amami Oshima but disappeared entirely in the northern region. The results clearly indicate that the latitudinal limit of <em>Calcarina gaudichaudii</em> lies at ∼28.5°N. The possible controlling factor is the loss of foraminiferal habitats associated with the absence of shallow lagoons in the northern region. This study suggests that the northern region of the Ryukyus is the front line of biogeographic extension of shallow-water calcarinids, which needs to be monitored.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"203 ","pages":"Article 102559"},"PeriodicalIF":1.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}