Marine Micropaleontology最新文献

{"title":"Holocene paleo-redox conditions in a microbial dolomitic lake using benthic foraminifera as bioindicators","authors":"Daniel François ,&nbsp;Camila Areias ,&nbsp;Nayara Dornelas ,&nbsp;Luiz G.R. Sá-Valle ,&nbsp;Anna Paula Soares Cruz ,&nbsp;José Carlos Sícoli Seoane ,&nbsp;Crisógono Vasconcelos ,&nbsp;Nicolás M. Stríkis ,&nbsp;Daniel Souza dos Santos ,&nbsp;Adina Paytan ,&nbsp;Cátia F. Barbosa","doi":"10.1016/j.marmicro.2023.102319","DOIUrl":"10.1016/j.marmicro.2023.102319","url":null,"abstract":"<div><p>Brejo do Espinho coastal lake (LBE) is one of the few places in the world where dolomite [CaMg(CO₃)₂<span>] is precipitating in the modern environment under microbially induced processes and low oxygen conditions. We use pore morphometry of the foraminifera </span><em>Ammonia</em> cf. <em>A. veneta</em> to evaluate paleo-O₂<span> dynamics during the dolomitic depositional phase that took place at LBE in the late Holocene<span><span>. Foraminiferal community structure was also investigated, and results were compared to bulk isotopic composition of carbonates, </span>total organic carbon (TOC), and X-ray Diffraction of sediments (XRD). The correlation matrix (Spearman method) showed that </span></span><em>Ammonia</em> test pores morphometric parameters displayed significant correlations with overall biotic and geochemical data, with pore area presenting a relatively higher association. <em>Ammonia</em> test pores were primarily controlled by the degradation of organic matter (Pore area-TOC, <em>r =</em> −0.84), and foraminifera density appeared to be influenced by oxygen changes, with a higher abundance in the highest porosity intervals (Pore area-N, <em>r =</em> 0.82), indicating a direct effect of oxygen penetration on species dominance. These data also reveal a tolerant behavior of the low-O₂ bioindicator species <em>Quinqueloculina laevigata</em> and <em>A. veneta</em>. Understanding microbe-mineral interactions is critical for interpreting paleo records, and our data provide strong support for coupling assemblage and pores analysis as paleo-O₂ bioindicators for paleo-redox coastal settings.</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"186 ","pages":"Article 102319"},"PeriodicalIF":1.9,"publicationDate":"2023-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138539799","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":"Conodonts paleobiogeographic dynamic of the Pennsylvanian epicontinental sea Itaituba-Piauí, in the northern intracratonic Brazilian basins, Western Gondwana","authors":"Sanmya Karolyne Rodrigues Dias ,&nbsp;Andrés Felipe Rojas Mantilla ,&nbsp;Martín Andrés Leon Caffroni ,&nbsp;Ana Karina Scomazzon ,&nbsp;Sara Nascimento ,&nbsp;Amanda Pericolo da Rosa ,&nbsp;Renato Sol Paiva de Medeiros ,&nbsp;Paulo A. Souza ,&nbsp;Afonso César Rodrigues Nogueira ,&nbsp;Jordana Maria Viccari","doi":"10.1016/j.marmicro.2023.102318","DOIUrl":"https://doi.org/10.1016/j.marmicro.2023.102318","url":null,"abstract":"<div><p><span>During the Pennsylvanian, icehouse glacioeustasy<span> and the debasement of Western Gondwana<span> 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 a rich variety of marine (e.g., invertebrates, conodonts, foraminifers) and continental (plant pollen-spore assemblages) fossils. This paper presents the conodonts retrieved from outcrops and wells in the Carauari (Solimões Basin), Itaituba (Amazonas Basin), and the Piauí (Parnaíba Basin) formations. The conodonts recovered from these formations include </span></span></span><em>Idiognathodus, Neognathodus, Adetognathus, Idiognathoides, Diplognathodus, Declinognathodus</em>, and <em>Hindeodus</em><span>. Biostratigraphic correlation of this Pennsylvanian conodont assemblage is possible between the three studied basins. The conodont-bearing marine units can identify transgression episodes when the Itaituba-Piauí sea inundated these basins.</span></p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"186 ","pages":"Article 102318"},"PeriodicalIF":1.9,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138466001","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":"Origin and evolution of the Neogene calcareous nannofossil Ceratolithus","authors":"Carlos Lancis ,&nbsp;José-Enrique Tent-Manclús ,&nbsp;José-Abel Flores","doi":"10.1016/j.marmicro.2023.102310","DOIUrl":"https://doi.org/10.1016/j.marmicro.2023.102310","url":null,"abstract":"<div><p>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. <em>Orthorhabdus rugosus</em> is a nannolith with three blades (sinistral, median, and dextral) that first appeared during the Serravallian, it is not-birefringent in its stable orientation. It shows a high morphological variability time-interval at the end of the Messinian to the basal Pliocene (5.5 to 5 Ma) during which <em>Ceratolithus</em> (5.484 Ma) evolved. Changes occurred in the sinistral and median blades, whilst the dextral blade was reduced. <em>Ceratolithus finifer</em> n. comb is the first species of the evolutionary line. The nannolith stable position changed during its evolution, resulting in the older forms showing low birefringence and the younger ones moderate to high birefringence in the most stable orientation. <em>Ceratolithus acutus</em>, with an arrowhead shape, <em>Ceratolithus armatus,</em> and the morphologically distinct <em>C. larrymayeri</em> evolved from <em>C. finifer</em> with all three species showing high birefringence. The previous <em>O. rugosus</em> and <em>C. finifer</em> continued. Finally, <em>C. armatus</em> gives rise to <em>C. cristatus</em>. <em>Ceratolithus atlanticus</em> and <em>C. tricorniculatus</em> also evolved from <em>C. finifer.</em> All the species mentioned become extinct during the Pliocene except <em>Ceratolithus cristatus</em> that lives today. Detailed observations permit the analysis of the evolutionary trends of the group, possible mechanisms, patterns, and processes of speciation, and establish new criteria to define the species that, by their relative abundance and short geologic range, have permitted adjustment of biostratigraphic markers for this period.</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"186 ","pages":"Article 102310"},"PeriodicalIF":1.9,"publicationDate":"2023-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0377839823001093/pdfft?md5=872c09f650cd720a2bd3cb968ea7c068&pid=1-s2.0-S0377839823001093-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138466360","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}

{"title":"Local hydrodynamic in coastal system affects the coccolithophore community at a short spatial scale","authors":"Marina Addante ,&nbsp;Michael Grelaud ,&nbsp;Gerald Langer ,&nbsp;Patrizia Maiorano ,&nbsp;Sergio Bonomo ,&nbsp;Marta Álvarez ,&nbsp;Roberta Johnson ,&nbsp;Patrizia Ziveri","doi":"10.1016/j.marmicro.2023.102309","DOIUrl":"https://doi.org/10.1016/j.marmicro.2023.102309","url":null,"abstract":"<div><p>Coccolithophores are an ecologically and biogeochemically important group of calcifying marine plankton, contributing globally to both the organic carbon<span> pump and the carbonate counter pump. Understanding their distribution in today's ecosystems is crucial for both paleoenvironmental reconstruction<span><span> and for predicting their fate under climate change and environmental pollution. Traditionally regarded as </span>open ocean dwellers, more recent studies have highlighted their importance in coastal systems.</span></span></p><p><span>Here we describe the coccolithophore community in the Catalan Sea (Northwestern Mediterranean), off the Ebro River Delta, based on an oceanographic survey conducted in autumn 2019. We identify three environmentally distinct regimes: mixed (mostly shallow), transition (upper photic layers offshore), and stratified deep waters (below 75 m). Total coccolithophore density is driven by </span><em>Emiliania huxleyi</em> and peaks in the mixed zone where nutrient concentrations are low, but nitrite concentrations are high. We propose that peak cell densities are partly explained by a switch from nitrate to nitrite usage similar to the behavior of diatoms. Species diversity peaks in deeper offshore waters due to vertical stratification. <em>Helicosphaera carteri</em> and <em>Algirosphaera robusta</em> benefit from <em>E</em>.<em>huxleyi</em> decrease both in coastal and offshore environment.</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"185 ","pages":"Article 102309"},"PeriodicalIF":1.9,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138437016","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":"The origin and significance of euhedral apatite crystals on conodonts","authors":"Daniele Malferrari ,&nbsp;Annalisa Ferretti ,&nbsp;Luca Medici","doi":"10.1016/j.marmicro.2023.102308","DOIUrl":"10.1016/j.marmicro.2023.102308","url":null,"abstract":"<div><p>Crystal overgrowth on fossil remains is well-documented in the literature. Attention has specifically focused on bioapatite (<em>i.e.</em>, 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 crystals formed on the surface of conodont elements compared with that of crystal-free surfaces. Euhedral crystals are by definition crystals characterized by sharp faces, developing solids that, for apatite, assume the form of hexagonal prisms, reflecting its crystal symmetry. Late Ordovician (<em>Amorphognathus ordovicicus</em> Zone) conodonts from two localities in Sardinia and the Carnic Alps (Italy) are herein investigated. Conodont elements reveal the occurrence of smooth surfaces and surfaces partially covered with euhedral crystals. Since euhedral crystals did not reasonably grow during the organism's lifetime, the REE and HFSE analysis can provide important insights into the crystal growth process. The experimental results indicated a substantial contribution of diagenetic imprinting for all the analyzed material, although more evident on euhedral crystals that are significantly enriched in middle and, subordinately, in heavy REE with respect to smooth surfaces. The positive correlations between La + Th <em>vs</em> log[ΣREE] and Ce + Th <em>vs</em> log[ΣREE] could support the hypothesis that the neoformed euhedral crystals grew also by depleting the pristine bioapatite of the conodont elements. Nevertheless, the occurrence of two types of apatite cannot be ruled out: euhedral crystals as neoformed products of diagenetic processes and smooth surfaces as remains of the pristine conodont bioapatite after diagenesis.</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"186 ","pages":"Article 102308"},"PeriodicalIF":1.9,"publicationDate":"2023-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S037783982300107X/pdfft?md5=5693b04e86c1b22c5e7e3984e5051c53&pid=1-s2.0-S037783982300107X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135670394","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}

{"title":"Significance of conodont data for explaining geosystem perturbations during the Middle Devonian Kačák Episode","authors":"Katarzyna Narkiewicz ,&nbsp;Marek Narkiewicz ,&nbsp;Alicja Wudarska","doi":"10.1016/j.marmicro.2023.102307","DOIUrl":"https://doi.org/10.1016/j.marmicro.2023.102307","url":null,"abstract":"<div><p><span><span>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<span>. 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 correlation of relevant marine strata. Conodont </span></span>biofacies may serve to document environmental changes connected with KE, in particular the sealevel rise at its beginning, followed by a regressive trend. Nevertheless, the familiar </span><em>Icriodus/Polygnathus</em><span><span><span> ratio should be carefully applied as an indication of water depth and nearshore vs. offshore position, being controlled also by other factors, such as paleolatitude and/or climate. </span>Oxygen isotopes<span> in conodont apatite<span>, studied using secondary ion mass spectrometry technique evidence a warming at the onset of KE, based on the new data from the open marine facies of the Prague Basin. At the same time, they indicated climate-controlled </span></span></span>salinity fluctuations in the epeiric Belarusian Basin. The present investigations as well as previous results suggest caution when analyzing thermally altered conodonts which may result in biased oxygen isotope signatures. The present experience suggests the conodont colour alteration index CAI 3 as a boundary value above which the caution is necessary.</span></p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"185 ","pages":"Article 102307"},"PeriodicalIF":1.9,"publicationDate":"2023-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136572273","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":"Paleocene–Eocene boundary in the Gabal El-Gir, east Qena, Egypt: Paleoenvironment and sequence stratigraphy interpretations","authors":"Islam El-Sheikh ,&nbsp;Kamel H. Mahfouz ,&nbsp;Abdullah O. Al-Ameer ,&nbsp;Amr A. Metwally","doi":"10.1016/j.marmicro.2023.102306","DOIUrl":"10.1016/j.marmicro.2023.102306","url":null,"abstract":"<div><p><span><span><span>Comprehensive field, litho-, biostratigraphy<span>, 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 </span></span>nannofossils, planktonic, and benthic foraminiferal assemblages. </span>Benthic foraminifera assemblages indicate a remarkable turnover across the PETM. The extinction of </span><em>Angulogavelinella avnimelechi</em><span> at the base of the PETM represents a significant marker for the base of the benthic foraminifera extinction event at this site and other neritic sites in the Tethyan region. The dominance of calcareous planktonic excursion taxa at the base of the PETM indicates adaptation to extremely warm sea surface temperatures<span> and low nutrient levels. Also, our data suggests that the biotic responses to environmental change in the early Eocene resembled those observed in the early Eocene hyperthermals at the nearbay Dababiya and El-Ballas sections. This could indicate that similar processes characterized the Egyptian sedimentary basin<span> during the early Eocene. Stratigraphically, despite the limited distance between the studied sections, the Dababiya Quarry Member (DQM) in El-Gir-1 resemble those of the Global Stratotype<span> Section and Point (GSSP) but reduced in thickness. While in El-Gir-2, the lower part of the DQM was missing. These findings could indicate that the DQM was deposited in a submarine channel<span>. Three third-order depositional sequences were recognized covering the P–E interval. The reconstructed sea level curve shows the presence of eustatic similarities with the global sea level.</span></span></span></span></span></p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"185 ","pages":"Article 102306"},"PeriodicalIF":1.9,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135850354","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":"Merging databases for CNN image recognition, increasing bias or improving results?","authors":"Martin Tetard ,&nbsp;Veronica Carlsson ,&nbsp;Mathias Meunier ,&nbsp;Taniel Danelian","doi":"10.1016/j.marmicro.2023.102296","DOIUrl":"https://doi.org/10.1016/j.marmicro.2023.102296","url":null,"abstract":"<div><p>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 intensity leading to potential bias in identification when using datasets or CNNs from another institute.</p><p>One might then question if combining datasets acquired in different conditions is likely to improve the efficiency of the resulting CNN by increasing the number of images and integrating lighting variability into the learning process, or on the contrary introduce bias in the CNN training by adding a recurrent noise, common to all classes, through a substantial light and contrast variability.</p><p><span>In order to ease collaboration between laboratories, two datasets of middle Eocene </span>radiolarian images, acquired separately at GNS Science (NZ) and the University of Lille (France), were generated to assess the accuracy of CNNs trained on both datasets individually, and also when combined into a third dataset. The performance of the three resulting CNNs was then evaluated on new images acquired at both institutions.</p><p>Finally, the new radiolarian dataset generated at GNS allowed to easily detect unknown taxa, which are otherwise abundant in the studied material. Seven new species are described: <em>Ceratospyris metroid</em> n. sp., <em>Ceratospyris okazakii</em> n. sp., <em>Desmospyris biloba</em> n. sp., <em>Botryostrobus lagena</em> n. sp., <em>Buryella apiculata</em> n. sp., <em>Lophocyrtis cortesei</em> n. sp., and <em>Cromyosphaera fulgurans</em> n. sp.</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"185 ","pages":"Article 102296"},"PeriodicalIF":1.9,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49738801","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":"The biphasic life cycle of the non-spinose planktonic foraminifera is characterised by an aberrant coiling signature","authors":"Kate F. Darling ,&nbsp;Katrine Husum ,&nbsp;Isabel S. Fenton","doi":"10.1016/j.marmicro.2023.102295","DOIUrl":"https://doi.org/10.1016/j.marmicro.2023.102295","url":null,"abstract":"<div><p>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 <em>Neogloboquadrina pachyderma</em> culture confirms that they do have a biphasic reproductive cycle and the agamonts may exhibit dimorphism in coiling direction. In this study we examine the morphology of normal and aberrant coiling tests of both <em>N. pachyderma</em> and <em>N. incompta</em> from three Arctic and North Atlantic water masses, to explore whether aberrant coiling is an indicator of a biphasic life cycle in the non-spinose planktonic foraminifera group as a whole. Using a Nano-Computed Tomography scanning approach, we morphologically compared the proloculus and growth trajectories of aberrant and normal coiling tests. Aberrant coiling tests were found to have a slightly larger proloculus and test size, consistent with a left coiling <em>N. pachyderma</em> agamont in the literature. This degree of dimorphism is insufficient to discriminate agamonts in the wild population and coiling direction remains their only distinguishable feature without further morphological investigation. The constant low-level aberrant coiling signature in a range of non-spinose planktonic foraminiferal genera implies that a biphasic life cycle is the principal mode of reproduction in the non-spinose planktonic group.</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"185 ","pages":"Article 102295"},"PeriodicalIF":1.9,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49738567","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":"Morphometrics and machine learning discrimination of the middle Eocene radiolarian species Podocyrtis chalara, Podocyrtis goetheana and their morphological intermediates","authors":"Francisco Pinto ,&nbsp;Veronica Carlsson ,&nbsp;Mathias Meunier ,&nbsp;Bert Van Bocxlaer ,&nbsp;Hammouda Elbez ,&nbsp;Marie Cueille ,&nbsp;Pierre Boulet ,&nbsp;Taniel Danelian","doi":"10.1016/j.marmicro.2023.102293","DOIUrl":"https://doi.org/10.1016/j.marmicro.2023.102293","url":null,"abstract":"<div><p><span>We present various approaches to distinguish the middle Eocene species </span><em>Podocyrtis chalara</em> and <em>Podocyrtis goetheana</em>, 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 <em>Podocyrtis</em> sp. cf. <em>P. chalara</em> and <em>Podocyrtis</em> sp. cf. <em>P. goetheana</em><span>. We used two methods of classification, namely Linear Discriminant Analysis<span> (LDA) and machine learning using artificial neural networks. LDA performed on the morphometric data reveals a good discrimination for </span></span><em>P. chalara</em>, <em>P. goetheana</em> and <em>Podocyrtis</em> sp. cf. <em>P. goetheana</em>, but not for <em>Podocyrtis</em> sp. cf. <em>P. chalara</em>. We used three approaches of machine learning based on different neural networks: a Convolutional Neural Network (CNN) and two Spiking Neural Networks (SNNs). Each of these neural networks was trained based on classified images of the two morphospecies and their morphological intermediates, thus constituting a different set of input data than the morphometric dataset for LDA. The neural network approaches identified the same three morphospecies recognized by LDA from a dataset of traditional measurements, i.e. <em>P</em>. <em>chalara</em>, <em>P</em>. <em>goetheana</em> and <em>Podocyrtis</em> sp. cf. <em>P. goetheana</em>, with up to 92% accuracy. Our results highlight the great potential and promising perspectives of machine learning and neural networks in the application of image-based object recognition for morphological classification, which may also contribute to more objective taxonomic decisions.</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"185 ","pages":"Article 102293"},"PeriodicalIF":1.9,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49738564","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}