Micropaleontology最新文献

{"title":"Systematics, age, paleoecology and paleobiogeography of Middle to Late Jurassic benthic foraminiferal assemblages from Jumara Dome, Kutch, Gujarat, India","authors":"Syed Md Wasim, A. Talib, S. H. Alvi","doi":"10.47894/mpal.67.1.06","DOIUrl":"https://doi.org/10.47894/mpal.67.1.06","url":null,"abstract":"The studied section of the Patcham-Chari formations of Middle to Upper Jurassic rocks exposed at Jumara Dome, Kutch Basin, Gujarat, India yielded rich foraminiferal assemblages comprising 104 species, of which 49 are reported for the first time from the Indian region. The foraminiferal species are systematically described and illustratedwith the help of SEMimaging. The foraminiferal assemblages are used to interpret the age, paleoecology, and paleobiogeography. Although most of the foraminiferal species are rather long ranging, on the basis of a large number of species characteristic of the Bathonian, Callovian and Oxfordian, globally as well as in the Indian region, a Bathonian to Oxfordian age is assigned to the studied sequence. Based on the dominance of the suborder Lagenina, superfamily Nodosariacea, family Vaginulinidiae, calcareous hyaline forms, the genus Lenticulina, high Fisher’s diversity index, morphogroup J2, shallow infaunal life habit, detrivores, bacterial scavengers, and omnivores feeding strategy in the assemblages, a shallow water, near shore, open marine environment ranging from mid- to outer shelf with normal salinity and normal to well-oxygenated waters with high nutrient influx is interpreted for the studied assemblages. The Middle to Late Jurassic Jumara foraminiferal assemblages are assigned to a separate province of the Antiboreal Realm, the Indo-East African Province, located at the southern margin of the Tethyan Realm and transitional between the Tethyan and the Antiboreal realms.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70444921","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":"Eocene larger foraminiferal biostratigraphy, depositional history and paleogeography of the Sylhet Limestone of the Mikir Hills of Assam, NE India: Implications for an Open Tethys","authors":"Shantajhara Biswal, Kapesa Lokho, U. Shukla, K. Whiso, K. Prakash","doi":"10.47894/mpal.67.5.01","DOIUrl":"https://doi.org/10.47894/mpal.67.5.01","url":null,"abstract":"This study presents results of integrated larger foraminiferal biostratigraphy, lithofacies and stable carbon isotope (13 C org) analysis carried out in the Sylhet Limestone of Dillai Parbat Limestone Mine succession, Karbi Anglong District, Assam. Larger foraminiferal assemblages assign a middle Eocene age to the studied succession of Sylhet Limestone. The Shallow Benthic Zone (SBZ) 13 and SBZ 16-18 and a barren interval in between is recognized in the studied part of the Sylhet Limestone. The SBZ 13 Zone (early Lutetian) is represented by fossiliferous limestone at the base of the section and is inferred to have been deposited in a subtidal environment. The overlying barren interval lies in the arenaceous interval and was likely deposited in a subtidal channel sand shoaling bars. The upper part of the section ismarked by SBZ16-18 (late Lutetian to Bartonian) and was deposited in subtidal channel sand inner neritic zone environments, followed by intertidal marl to subtidal limestone. The organic carbon stable isotopic data reveals a sharp negative excursion at about 34-35m of the succession, which may be correlated with Middle Eocene Climatic Optimum (MECO) and/or vegetation types. This and earlier studies from India and elsewhere indicate that during the middle Eocene, the Neo-Tethys Sea was open and connected through the East and West coasts of India, Northeast India, western Himalaya, and most of the Middle East and southeast Europe. This vast area produced enormous amount of petroleum.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70445561","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":"Septfontainella carpatobalcanica n. gen., n. sp., a new hauraniid foraminifera from the upper Berriasian of Serbia and Romania","authors":"F. Schlagintweit, I. Bucur, George Pleș","doi":"10.47894/mpal.67.6.05","DOIUrl":"https://doi.org/10.47894/mpal.67.6.05","url":null,"abstract":"Septfontainella (type-species S. carpatobalcanica n. sp.), a new genus of larger benthic foraminifera (family Hauraniidae, subfamily Amijiellinae) is described from the upper Berriasian of the Carpatho-Balkanides, eastern Serbia and Romania (Southern Capathians), both part of the Getic domain. It is characterized by large elongate dimorphic tests with a reduced coiled stage and a rectilinear-uniserial adult part with chambers displaying a coarse and irregular subepidermal network. Triangular-shaped first order radial partitions extend into the chamber lumen attaching to the succeeding septum. Septfontainella gen. nov. is compared with the Lower Jurassic Cymbriaella Fugagnoli and the Lower Cretaceous Bramkampella Redmond. Septfontainella n. gen. further substantiates the occurrence of a Berriasian origination event of larger benthic foraminifera in inner carbonate platform facies of the Neotethysian realm.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70446076","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":"Little pieces of mystery from the Silurian of the Dingle Peninsula, Ireland","authors":"A. Ferretti, Lorenzo Serafini","doi":"10.47894/mpal.67.6.03","DOIUrl":"https://doi.org/10.47894/mpal.67.6.03","url":null,"abstract":"Three-dimensionally preserved fragments of the enigmatic organism Sandvikina, previously reported from the Silurian of Ireland, Scotland and Scandinavia, were recovered from the original Irish material that had revealed the problematic in thin sections. The new specimens derive from conodont residue and document silicified sectors of the distal part of the skeleton. Adifferent pattern characterizes the outer and inner walls, with an external net-like reticulated and an internal continuous and apparently imperforate framework, getting therefore a filter-like feeding system function highly improbable.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70445766","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":"Nephrolepidina and unispiralled Miogypsinidae from the Oligo-Miocene toe-of-slope succession of Gran Sasso (L'Aquila, Central Apennines - Italy): biometric and evolutionary remarks","authors":"F. Schiavinotto, A. Benedetti","doi":"10.47894/mpal.67.5.04","DOIUrl":"https://doi.org/10.47894/mpal.67.5.04","url":null,"abstract":"A biometric analysis was performed on twelve Nephrolepidina and ten Miogypsina and Miogypsinoides populations, coming from the Tre Valloni section, an Oligo-Miocene calcarenitic toe-of-slope succession outcropping in the southern sector of Gran Sasso (L'Aquila, Central Apennines - Italy). Miogypsina populations are investigated applying two essential parameters, i.e., the number of the nepionic chambers and the protoconch diameter. Previously detected evidences of reworking in the same material suggested to use some cautions to avoid misleading results. A mixed typological-statistical methodology is used, leading from starting \"disordered\" assemblages to final \"virtual but reliable\" populations, cleaned up from reworked specimens, in order to implement the accuracy of the biostratigraphic results. This goal is reached for the lower part of the succession only. According to the biometric limits proposed for the various chronospecies in the recent literature, the resulting populations are referred to Miogypsinoides ex. interc. complanatus-formosensis up to Md. bantamensis, and to Miogypsina basraensis up to M. ex. interc. gunteri-tani. This sequence of taxa, in general, is in agreement with the principle of nepionic acceleration, with a progressive reduction in the average number of nepionic chambers (X), arranged in a single spiral, just peculiar in the more primitive populations. Miogypsinoides bantamensis and Miogypsina basraensis are recognized biometrically for the first time in the Central Apennines. Nephrolepidina populations are investigated applying the recently introduced biometry of the fifth stage of the neanic equatorial chamberlets, supplying additional data about parameters and factors that had already demonstrated to have taxonomic-biostratigraphic significance. The biometric analysis of the embryo-nepionic stages was performed as an integration of the data obtained in a previous study, excluding the uppermost samples in which Nephrolepidina is clearly reworked, being characterized by primitive morphology, i.e., almost isolepidine embryo, few adauxiliary chamberlets, and ogival equatorial chamberlets. The neanic data evidence that the \"Degree of stolonic distalization\" (Factor FD5) and the \"Shape Index\" (Factor SI5), at the 5th nepionic stage of the population have a very good fitting with the previously evidenced Neanic acceleration, as the overall trend to modify the shape of the equatorial chambers, connected with a gradually more distal position of the radial stolons. Unispiralled Miogypsina, associated with Nephrolepidina at an advanced evolutionary stage, suggest a continuous reworking of primitive miogypsinids, without an involvement of more evolute bispiralled forms. The biostratigraphic assessment of the Venacquaro and Glauconitic Calcarenite formations is improved, assigning the Venacquaro Formation to the Chattian-lowermost Aquitanian (SBZ22B-basal SBZ24) and the base of the Glauconitic Calcatenite to the Aquitanian (SBZ2","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70445980","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":"Taxonomic reassessment of four larger benthic Foraminifera (soritoids and orbitolinids) described from the Lower to mid-Cretaceous shallow-water carbonates of Iraq","authors":"L. Consorti, F. Schlagintweit","doi":"10.47894/mpal.67.5.05","DOIUrl":"https://doi.org/10.47894/mpal.67.5.05","url":null,"abstract":"Four Cretaceous foraminifers belonging to the subfamilies Pseudorhapydionininae, Orbitolininae and Dictyoconinae are here taxonomically revised: Pseudorhipidionina tubaensis, Bicyclina rifaiensis, Orbitolina arcuala, and Simplorbitolina nakhali. It is revealed that they should be considered junior synonyms of several existing species or inaccurately defined for specific identification. The new nominal names introduced to indicate such synonyms are invalidated, thus they are to be considered as nomen nudum.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70445995","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":"Transfer of type specimens of Caribbean Foraminifera and Ostracoda to the European Micropalaeontological Reference Centre","authors":"B. Wilson","doi":"10.47894/mpal.67.1.07","DOIUrl":"https://doi.org/10.47894/mpal.67.1.07","url":null,"abstract":"While working on Trinidad and Tobago and the western tropical Atlantic Ocean, the author published four papers (Wilson 2006a, 2006b, 2006c;Wilson et al. 2011) that included descriptions of ten new species of foraminifera and ostracoda from the Neogene of the SE Caribbean Sea. These holotypes and associated paratypes have now been transferred to the European Micropalaeontological Reference Centre, AGH, University of Science and Technology, Krakow, Poland, for safekeeping. Among the foraminifera, these are: Amphistegina martybuzasi Wilson, Ramkissoon and McLean 2011; Bolivina jiattongi Wilson 2006; Textularia carrbrowni Wilson 2006; Textularia framptoni Wilson 2006; and Textularia sawhi Wilson 2006. Regarding ostracodes, they are: Bythoceratina coimbrai Wilson 2006; Cytheropteron bremani Wilson 2006; Polycope swietinia Wilson 2006; Polycope trinitatensis Wilson 2066; and Pterygocythereis fithiani Wilson 2006. The specimen slides have been curated in Cabinet 7, Drawer 27.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70444938","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":"Moncharmontia De Castro 1967, benthic foraminifera from the middle-upper Cenomanian of the Sarvak Formation of SW Iran (Zagros Zone): a CTB survivor taxon","authors":"F. Schlagintweit, M. Yazdi-Moghadam","doi":"10.47894/mpal.67.1.03","DOIUrl":"https://doi.org/10.47894/mpal.67.1.03","url":null,"abstract":"Moncharmontia apenninca (De Castro 1966) is widely reported in the Upper Cretaceous (Turonian-Campanian) shallow-water successions of the Neotethyan realm (e.g., Italy, Croatia). With its \"First Appearance Datum\" (FAD) in the lowermost Turonian, it is considered a newcomer taxon in the aftermath of the Cenomanian/Turonian boundary (CTB) extinction event, and therefore a member of the Upper Cretaceous Global Community Maturation Cycle. Its common presence in the middle-pro parte upper Cenomanian Sarvak Formation and time-equivalent strata in Mexico (Valles-San Luis Potosi Platform) document that it represents a CTB extinction survivor taxon like Dicyclina, Nezzazata, Reticulinella and several others. The different local \"FAD's\" of Moncharmontia might possibly be linked to latitudinal differences, i.e., an earlier evolution of the species in the near-equatorial area (Mexico, Iran) compared to the low-middle latitudinal occurrences in the peri-Mediterranean realm (e.g., Italy, Turkey).","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70444746","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":"Automating taxonomic and systematic search of benthic foraminifera in an online database","authors":"A. Amao","doi":"10.47894/mpal.67.6.06","DOIUrl":"https://doi.org/10.47894/mpal.67.6.06","url":null,"abstract":"Recent advances in the applications of deep neural networks in computer vision tasks such as image classification has seen a tremendous surge in interest. Several image classification algorithms can now be leveraged in automating some tedious tasks associated with benthic foraminifera research especially in sample picking, taxonomy and systematics. In this study, a small image identification model was built with 414 SEM micrographs representing twenty-one species of benthic foraminifera, using a convolutional neural network which achieved 84% model accuracy and 75% validation accuracy on previously unseen images. The model was also deployed through a web application to demonstrate how it may be useful in augmenting online databases such as the Ellis Messina catalogue and the World Register of Marine Species. These services although very valuable, can be modernized with image search functionalities to enhance their perpetual usefulness and continuity.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70445741","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":"A Neotype for Neogloboquadrina atlantica (Berggren 1972)","authors":"M. Kaminski, W. Berggren","doi":"10.47894/mpal.67.1.08","DOIUrl":"https://doi.org/10.47894/mpal.67.1.08","url":null,"abstract":"Neogloboquadrina atlantica (Berggren 1972) is one of the most common planktonic foraminiferal species in the Upper Miocene and Pliocene at DSDP/IODP sites in the northern Atlantic. It was originally described from the upper Pliocene at DSDP Site 116 in the Rockall Trough, northeastern Atlantic. In the original description of the species, the depository of the illustrated type specimens was not specified. One of us (WAB) was under the impression that the illustrated type specimens of Neogloboquadrina atlantica had been sent to the Cushman Collection at the Smithsonian Institution. Unfortunately there is no record of the specimen slides having ever arrived at the museum (B. Huber, personal communication, 2020). Fortunately, the second author is still in possession of the shipboard sample residues from DSDP Leg 12, and was able to select a neotype specimen to replace the missing illustrated holotype. The purpose of this note is to designate a neotype specimen for Neogloboquadrina atlantica and to specify a repository for the permanent archive of the neotype and paraneotypes.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70445254","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}