Marine Micropaleontology最新文献

{"title":"Sedimentary record of Polysphaeridium zoharyi (cyst of Pyrodinium bahamense) in El Colorado Lagoon, Gulf of California","authors":"Tomasa Cuellar-Martinez,&nbsp;Rosalba Alonso-Rodríguez,&nbsp;Ana Carolina Ruiz-Fernández,&nbsp;Joan-Albert Sanchez-Cabeza","doi":"10.1016/j.marmicro.2025.102472","DOIUrl":"10.1016/j.marmicro.2025.102472","url":null,"abstract":"<div><div>The temporal variations in abundances (cyst g⁻¹ and percentages) and fluxes (cyst cm⁻² yr⁻¹) of dinoflagellate cysts, including <em>Polysphaeridium zoharyi</em> from the toxic species <em>Pyrodinium bahamense</em>, were analyzed in a ²¹⁰Pb-dated sediment core from El Colorado Lagoon (Mexico) to investigate potential natural and/or human-driven factors, influencing the proliferation of <em>P. bahamense</em>, by examining the relationship between <em>P. zoharyi</em> abundance and geochemical indicators of sediment provenance and hydrodynamic conditions. <em>P. zoharyi</em> was the most abundant and frequently observed species along the core. The dominance of <em>P. zoharyi</em> was linked to the prevalence of terrigenous influence in most core sections, implying enhanced nutrient delivery. In recent years (∼1970s), the decrease in <em>P. zoharyi</em> percentages was associated with a local shift in hydrodynamic conditions, as revealed by an increase in sand content, changes in the δ¹³C and δ¹⁵N composition, and higher concentrations of marine indicator elements (Br, Ca, Na, and Sr). The change in hydrodynamic conditions suggests enhanced connectivity with the sea, likely triggered by a meteorological event. We highlight the importance of integrating multiple geochemical proxies with cyst analysis to assess changes in species assemblages and how local conditions, such as shifts in hydrodynamic conditions, that can influence species composition. This study contributes to paleoecology and phytoplankton ecology by documenting species responses to natural and anthropogenic disturbances. It confirms the recurrence and dominance of <em>P. bahamense</em> cysts, a toxin-producing species associated with harmful algal blooms. The findings underscore the need for continued monitoring, contingency planning, and water quality protection in coastal ecosystems.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"199 ","pages":"Article 102472"},"PeriodicalIF":1.5,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144169576","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":"Extant benthic foraminifera from the Indonesian seas: An update of what we know so far and implications for future studies","authors":"Sinatrya D. Prayudi ,&nbsp;Suhartati M. Natsir ,&nbsp;Michael A. Kaminski","doi":"10.1016/j.marmicro.2025.102471","DOIUrl":"10.1016/j.marmicro.2025.102471","url":null,"abstract":"<div><div>To offer a comprehensive understanding of the diversity of benthic foraminifera in the Indonesian seas, we analyzed more than 70 years of datasets from both local and international sources. By reviewing articles covering three major biogeographical regions—Sunda Shelf, Sahul Shelf, and Wallacea—and their varying environmental conditions and depositional environments, we identified a total of 1164 species (including uncertain and genus-level identifications) belonging to 448 genera, 136 families, 14 orders, and four classes, in addition to 1116 genus-level naming (sp. and spp.). Our analysis also revealed 762 instances of taxonomic misnaming, with errors stemming from the use of unaccepted names and confusion between fossils, planktonic, and benthic assemblages. Additionally, most of the reviewed studies were found to be incomplete due to insufficient oceanographic data and a lack of detailed species counts, despite the importance of these factors in such research. This work establishes a robust baseline for future studies and highlights key issues that need to be addressed to avoid repeating past uncertainties and to promote more focused research on benthic foraminifera in the region.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"197 ","pages":"Article 102471"},"PeriodicalIF":1.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144098555","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":"Early impacts of Arctic amplification in the western North Water Polynya: A 400-year perspective","authors":"Kelsey A. Koerner ,&nbsp;Audrey Limoges ,&nbsp;Emily Pike-Connolly ,&nbsp;Nicolas Van Nieuwenhove ,&nbsp;André Rochon","doi":"10.1016/j.marmicro.2025.102470","DOIUrl":"10.1016/j.marmicro.2025.102470","url":null,"abstract":"<div><div>The North Water (NOW) polynya in northern Baffin Bay is known for persistent open water, attracting marine mammals and birds during winter. Ice bridges forming north of the NOW at constriction points in Nares Strait aid in sustaining these open water conditions. However, Arctic Amplification has weakened these ice bridges, altering water and sea ice flow into the NOW. We examined the effect of climate warming and recent ice bridge failures through 400 years of changes in the western NOW. We analyzed dinoflagellate cyst (dinocyst) assemblages in a surface sediment transect across the NOW to assess their distribution as indicators of surface water masses. We then analyzed dinocysts and geochemical proxies (carbon and nitrogen signatures) from two sediment cores in the western NOW. Results show the eastern NOW, influenced by the West Greenland Current (WGC), exhibits higher contributions of mixotrophic taxa and total dinocyst concentrations than the western region, influenced by Arctic water outflow. Sediment cores show a 300-year period of stability in the western NOW (1620–1920 CE), followed by an increase in mixotrophic taxa and total dinocyst fluxes, predating observed ice bridge failures. Around 1980 CE, higher abundances of <em>Operculodinium centrocarpum</em>, and cysts of <em>Polarella glacialis</em> and <em>Pentapharsodinium dalei</em>, suggest early sea ice retreat, seemingly attributable to increased WGC influence. These findings demonstrate the early impact of Arctic Amplification on the NOW, with significant changes starting in the first half of the 20th century, which contribute to understanding the timing and propagation of oceanographic changes in the polynya.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"197 ","pages":"Article 102470"},"PeriodicalIF":1.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143922850","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":"Deep-sea benthic foraminifera respond to rapid environmental changes in the central Red Sea during the last glacial period","authors":"Raphaël Hubert-Huard ,&nbsp;Yvonne Milker ,&nbsp;Gerhard Schmiedl","doi":"10.1016/j.marmicro.2025.102474","DOIUrl":"10.1016/j.marmicro.2025.102474","url":null,"abstract":"<div><div>This study investigates the response of deep-sea benthic foraminifera to changes in food fluxes and dissolved bottom water oxygen in the central Red Sea during the last glacial period (Marine Isotope Stages (MIS) 3 and 4). To assess variations in nutrient intrusion from the Arabian Sea and regional organic matter fluxes, we developed the Red Sea Productivity Index (RSPI) based on changes in sea level and African-Arabian monsoon intensity. We found four distinct species groups, each reflecting different ecological niches and opportunistic behavior. Overall, the fauna of MIS 3 is dominated by the generalist species <em>Bolivina subreticulata</em>, which co-occurs or alternates with other preferentially infaunal taxa of varying opportunistic responses. Changes in the dominance of the different species are primarily controlled by seasonal productivity and associated quantity and quality of available organic matter at the sea floor. This is reflected by a close correspondence of the RSPI and a succession of infaunal species, including <em>Uvigerina juncea</em> s.l., and <em>Bolivina variabilis</em> as the most opportunistic taxa, adapted to strong seasonal food pulses. The succession of the species groups are influenced by millennial-scale changes of the African-Arabian monsoon system and Red Sea deep-water ventilation. This suggests a close link to both low- and high-latitude Northern Hemisphere climate variability. Changes in glacial deep-water oxygenation seem to play an important role during MIS 4, when the dominance of <em>Bolivina persiensis</em> indicates a vertical expansion of the oxygen minimum zone. The high glacial deep-water salinities during sea-level lowstands also fostered the occurrence of miliolid taxa.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"197 ","pages":"Article 102474"},"PeriodicalIF":1.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144135128","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":"Benthic ostracods as environmental proxies in Nile Delta Coastal Lagoon","authors":"Sherif M. El Baz ,&nbsp;Abd-ElMonsef A. El-Badry ,&nbsp;Pamela Hallock ,&nbsp;Ahmed M. BadrElDin","doi":"10.1016/j.marmicro.2025.102469","DOIUrl":"10.1016/j.marmicro.2025.102469","url":null,"abstract":"<div><div>The coastal Nile Delta wetlands are essential in the protection of the cultivated deltaic land against sea level rise and are major resources for biodiversity and fisheries productivity. The Manzala Lagoon ranks highly polluted among the lacustrine coastal environments of the Nile Delta of Egypt. The environmental quality of the lagoon plummeted a few decades ago with the increase in massive quantities of untreated mixed discharges (agricultural, industrial, and municipal). To evaluate the environmental status of the lagoon requires both geochemical analyses and bioindicators. Total organic carbon and concentrations of seven potentially toxic elements (Pb, Cu, Cd, Zn, Ni, Co, Fe) were determined in 25 sediment samples collected during summer 2014, from which three pollution indices were calculated (Contamination Factor, Degree of Contamination, and Pollution Loading Index). In addition, ostracod assemblages were assessed in the very-fine and fine sand-size fractions of the sediments. The lagoonal environment is characterized by low total dissolved solids, abundant organic matter, heavy metal contamination by Pb, Co, Ni, and especially Cd, and low diversity ostracod assemblages. Six fresh- and brackish water ostracod species were documented, but the assemblage was overwhelmingly dominated (&gt;98 %) by stress-tolerant <em>Cyprideis torosa.</em> While this species correlated strongly with total dissolved solids and fine sediment textures, overall, the limited ostracod diversity and dominance of a stress-tolerant species reflects the compromised ecological quality of Manzala Lagoon.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"197 ","pages":"Article 102469"},"PeriodicalIF":1.5,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868944","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":"Ostracod and foraminiferal assemblages in Tébessa (Northeast Algeria): Insights into Santonian cooling effects","authors":"Sakina Nemouchi ,&nbsp;Sihem Salmi-Laouar ,&nbsp;Ahmed Awad Abdelhady ,&nbsp;Amor Deghaichia ,&nbsp;Mostafa M. Sayed ,&nbsp;Youssef Bazeen ,&nbsp;Michael Hesemann ,&nbsp;Mohamed Ahmed ,&nbsp;Mabrouk Boughdiri","doi":"10.1016/j.marmicro.2025.102468","DOIUrl":"10.1016/j.marmicro.2025.102468","url":null,"abstract":"<div><div>A well-exposed Coniacian-Santonian stratigraphic section in the Bir Mokadam Mountains, west of Tébessa (Algeria), was investigated through biostratigraphic and paleoenvironmental analyses focusing on planktic foraminifera and ostracods, respectively. The studied interval encompasses deposits from the Essen Formation, consisting predominantly of clayey marls. A total of 318 samples were collected and examined, leading to the identification of 26 planktic foraminiferal species distributed across 11 genera. The Coniacian is characterized by the presence of the <em>Dicarinella primitiva</em> and <em>Marginotruncana sinuosa</em> biozones, whereas the Santonian is distinguished by <em>Sigalia carpatica, Dicarinella asymetrica</em>, and <em>Globotruncanita elevata</em> biozones. The quantitative analyses revealed significant differences between the Coniacian and Santonian stages. The Coniacian and the lower parts of the Santonian exhibit higher diversity, characterized by a greater abundance of smooth ostracods, keeled and globular foraminifera. In contrast, the upper part of the Santonian is marked by a notable decrease in diversity and an increase in dominance of the ostracods and the also the planktonic foraminifera, indicating a less balanced ecological structure. The decline in diversity is herein tentatively attributed to a climate cooling and/or bottom-water minor dysoxia. Notably, there is a negative relationship between ostracod and foraminiferal abundances, the cause of which remains unclear and requires further investigations.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"197 ","pages":"Article 102468"},"PeriodicalIF":1.5,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847486","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":"Are there marine sedimentary losses and transgressions in the Southeast Bohai Sea during MIS 2-MIS 3?","authors":"Qingtong Wang ,&nbsp;Gayan Bandara ,&nbsp;Wenqin Jiang ,&nbsp;Feifei Wang ,&nbsp;Hongxian Chu ,&nbsp;Meiling Yin ,&nbsp;Chuanxiu Luo","doi":"10.1016/j.marmicro.2025.102461","DOIUrl":"10.1016/j.marmicro.2025.102461","url":null,"abstract":"<div><div>Sedimentary architecture dominated by transgression–regression cycles in the shallow Bohai shelf region contains information about global sea-level, climate and local tectonics. However, previous studies of transgression–regression cycles in this region at orbital timescales that extend back to the early Pleistocene are sparse. In this study, we present an integrated sedimentological, paleontological study of a 32.49 m (93kyr BP) core (HZK02) recovered from the Bohai Sea, China, for which an AMS ¹⁴C and five OSL dates-based age model is available. Compared with previous pollen study in the Bohai area, the results show that there were two significant transgressions that occur in MIS 5c, top part of MIS 2 and MIS 1, with abundant foraminifera from the near shore shallow sea of the continental shelf, corresponding with prevailing arboreal pollen dominated by <em>Pinus</em> and <em>Quercus</em>. While, terrestrial herbs such as <em>Artemisia</em> and Chenopodiaceae dominated during colder periods, such as MIS 4, MIS 5b, when sea levels dropped significantly, corresponding with a scarcity of foraminifera in terrestrial sediment layers from MIS 5b, MIS 5a, MIS 4, and MIS 3. We find that at depth of 8.18–6.10 m, with depth of only 2.08 m and very high sediment rate, the duration age last from 64,100 yr BP to 10,500 yr BP, which might indicate some missing part of the deposition of MIS 3 and MIS 2. The transgressions signal has been found in top part of MIS 2 sediment, hardly in MIS 3.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"196 ","pages":"Article 102461"},"PeriodicalIF":1.5,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704042","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":"Siliceous plankton flux and radiolarian community structure in the highly oligotrophic Ionian Sea (Eastern Mediterranean) – Imprints of climate variability","authors":"Marie Cueille ,&nbsp;Taniel Danelian ,&nbsp;Dimitra-Ioli Skouroliakou ,&nbsp;Elisavet Skampa ,&nbsp;Maria Triantaphyllou ,&nbsp;Alexandra Gogou ,&nbsp;Georgia Kambouri ,&nbsp;Ioanna Stavrakaki ,&nbsp;Koen Sabbe","doi":"10.1016/j.marmicro.2025.102460","DOIUrl":"10.1016/j.marmicro.2025.102460","url":null,"abstract":"<div><div>Based on sediment-trap material collected at 700 m depth from the oligotrophic southern Ionian Sea (Nestor site), this study explores for the first time the impact of seasonal and multiannual (2015–2017) climate variability on the siliceous plankton flux and radiolarian community structure at species level in the Eastern Mediterranean Sea. A total of 143 radiolarian taxa were identified, most of them at the species level. Juveniles represented 35–70 % of the total radiolarian flux. Thirty-nine diatom taxa were identified, including some freshwater species. Coinciding with organic carbon, opal and total mass fluxes, radiolarians and diatoms displayed rather similar pattern in seasonal flux variations, including two seasonal peaks. The first one was recorded in late winter (late February) 2015; it is regarded as the result of late winter intensification of water column mixing. The second peak in the siliceous plankton flux was recorded in late summer to early fall (August – September) of both years 2015 and 2017. This peak is interpreted to be the result of a local upwelling event following the reduced influence of the Pelops anticyclonic gyre. A third productivity event was recorded in April and May 2016, and is interpreted as being influenced by North African dust depositions. Despite the incompleteness of our sediment trap data series, our dataset is valuable as it is the first ever study conducted to the species level on polycystine radiolarian vertical export rates in the Mediterranean Sea, combined with insights into the temporal dynamics of siliceous zoo- and phytoplankton fluxes in the EMed.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"196 ","pages":"Article 102460"},"PeriodicalIF":1.5,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704044","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":"Phyletic evolution of calcareous nannofossil species Reticulofenestra oamaruensis: An example of microevolution preserved at IODP Site U1553 (Southern Pacific Ocean)","authors":"Valentina Catelli ,&nbsp;Davide Persico ,&nbsp;Davide Righi ,&nbsp;Isabella Raffi ,&nbsp;Chiara Fioroni ,&nbsp;Giuliana Villa","doi":"10.1016/j.marmicro.2025.102452","DOIUrl":"10.1016/j.marmicro.2025.102452","url":null,"abstract":"<div><div>The IODP Expedition 378 in the Southern Ocean (Campbell Plateau) recovered a Paleogene sedimentary section at Site U1553, cored through multiple holes (A - E) in the late Eocene-early Oligocene interval. Stratigraphic continuity and good preservation of calcareous nannofossils offered the opportunity to study the phyletic origin of <em>Reticulofenestra oamaruensis</em>, the biostratigraphic marker for the Eocene/Oligocene Transition (EOT) in the Southern Ocean (SO). We performed biometric and morphological analyses on <em>R. oamaruensis</em> and the related species <em>Reticulofenestra clatrata</em>, revealing intermediate morphotypes with characters between <em>R. clatrata</em> and <em>R. oamaruensis</em>. These transitional morphotypes, labeled <em>Reticulofenestra</em> transitional form 1 (<em>R</em>. t1) and <em>Reticulofenestra</em> transitional form 2 (<em>R</em>. t2), differ in size from the end members and are distinguished in two size categories: 10–12 μm and 12–14 μm respectively. The intraspecific evolutionary trend shows a gradual size increase of <em>R. clatrata</em>(8–10 μm) that, through intermediate steps represented by <em>R.</em> t1 and <em>R.</em> t2, leads to <em>R. oamaruensis</em> (≥14 μm). The two morphotypes are included in the species identification of <em>R. oamaruensis</em> and enter the stratigraphic record at successive levels, thus delineating a “lineage zone” useful in SO biostratigraphy. <em>R. clatrata</em> and medium – large <em>R. oamaruensis</em> disappear close to the Eocene/Oligocene Boundary. Based on the morphological homology, the progressively increasing size trend from <em>R. clatrata</em> to <em>R. oamaruensis</em>, their stratigraphic range continuity, and their same geographical distribution, we document a phyletic strain endemic to high southern latitudes, of which <em>R. clatrata</em> would represent the archetype.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"196 ","pages":"Article 102452"},"PeriodicalIF":1.5,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487764","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":"An integrative analysis of Plectocapillus antarcticus gen. et sp. nov. from Antarctica: Morphology, chemical composition, and phylogeny","authors":"Somin Lee ,&nbsp;Michael A. Kaminski ,&nbsp;Fabrizio Frontalini ,&nbsp;Jisu Yeom ,&nbsp;Nayeon Park ,&nbsp;Wonchoel Lee","doi":"10.1016/j.marmicro.2025.102451","DOIUrl":"10.1016/j.marmicro.2025.102451","url":null,"abstract":"<div><div>In this study, <em>Plectocapillus antarcticus</em> gen. et sp. nov., belonging to the Family Pseudobolivinidae Wiesner, 1931, Superfamily Spiroplectamminoidea Cushman, 1927, was described from Maxwell Bay, King George Island, Antarctica. The species is distinguished by its elongate, slender, and entirely biserial test, fragile, thin agglutinated wall, a globular, organic proloculus, and the areal, rounded to arch-like aperture. Notably, this species previously assigned taxonomically as <em>Spiroplectammina filiformis</em> Earland, 1934 or <em>Textularia tenuissima</em> Earland, 1933<em>,</em> in nearby areas. However, morphological comparison revealed differences in chamber arrangement, biserial pair number, test width, and proloculus wall composition. SEM-DES analysis identified Al, Ca, Fe, Mg, Si, and Ti as major chemical elements present in the test wall, along with the traces of K, Mn, Na, P, Ce, Cl, F, S, Sr, and Zr. Phylogenetic analysis of partial SSU rRNA and mitochondrial COI gene sequences confirmed that <em>P. antarcticus</em> forms a well-supported clade, sister to <em>Spiroplectammina biformis</em>. The slender, flexible test, organic proloculus, and inclusion of heavy element-rich minerals suggests potential adaptation to hypoxic or interstitial habitats. By integrating morphological, chemical, and molecular data, this study contributes to the expanding fundamental database and understanding of Antarctic foraminiferal diversity and emphasizes the necessity for continued research in the region.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"195 ","pages":"Article 102451"},"PeriodicalIF":1.5,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}