IF 1.6 4区地球科学

Geobios Pub Date : 2025-02-01 DOI: 10.1016/j.geobios.2024.08.009

M. Belvedere , F. Bertozzo , G. Botfalvai , L. Pandolfi

{"title":"First evidence of ichnopathologies in Rhinoceripeda tasnadyi tracks from the Miocene of Hungary","authors":"M. Belvedere , F. Bertozzo , G. Botfalvai , L. Pandolfi","doi":"10.1016/j.geobios.2024.08.009","DOIUrl":"10.1016/j.geobios.2024.08.009","url":null,"abstract":"<div><div>Despite a vast record, ichnological evidence of malformed or injured animals is extremely rare. During the re-examination of slabs collected from the Ipolytarnóc tracksite (Early Miocene, North Hungary) and housed at the Supervisory Authority for Regulatory Affairs, three “atypical” tracks were detected along the same trackway. They belong to the ichnotaxon <em>Rhinoceripeda tasnadyi</em>, attributed to a medium- to large-sized “hornless” Miocene rhinocerotids. The hoof of the left digit III appears to be split, rather than oval, at approximatively half of its width, giving an almost tetradactyl appearance to the footprints. The deformation due to overprinting is excluded because of the number of tracks showing the same variation. This injury/malformation could be identified as the atypical tracks belong to a trackway where the opposite impression is preserved and due to the large number of accessible <em>R. tasnadyi</em> footprints. These account for a wide range of the standard variability of the morphology at Ipolytarnóc. If the track record was limited, or when the atypical tracks do not belong to a trackway, it would not be possible to recognise those differences as ichnopathologies and, as a result, a different trackmaker would have been assessed, or a wrong ichnotaxonomical diagnosis would have been attributed.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"88 ","pages":"Pages 25-33"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387137","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}

引用次数: 0

New early Pliocene Rhinocerotidae findings from Tuscany (Italy) and the Pliocene rhinocerotine record in Italy 意大利托斯卡纳早更新世犀牛科的新发现和意大利早更新世犀牛的记录

IF 1.6 4区地球科学

Geobios Pub Date : 2025-02-01 DOI: 10.1016/j.geobios.2023.12.012

Luca Pandolfi , Alberto Collareta , Dariusz Nowakowski , Giovanni Bianucci , Lorenzo Rook

{"title":"New early Pliocene Rhinocerotidae findings from Tuscany (Italy) and the Pliocene rhinocerotine record in Italy","authors":"Luca Pandolfi , Alberto Collareta , Dariusz Nowakowski , Giovanni Bianucci , Lorenzo Rook","doi":"10.1016/j.geobios.2023.12.012","DOIUrl":"10.1016/j.geobios.2023.12.012","url":null,"abstract":"<div><div>An almost complete mandible from the Lower Pliocene deposits of Arcille (Tuscany) is described and investigated for the first time. The specimen is assigned to <em>Pliorhinus megarhinus</em>, which is documented in Italy from the latest Miocene to the mid-Pliocene. The studied specimen is larger than <em>Stephanorhinus etruscus</em> and <em>S. jeanvireti</em>, and morphologically fits <em>P. megarhinus</em> from the Early Pliocene of Montpellier (France), Vera Basin (Spain) and Val di Pugna Fangonero (Italy). This specimen represents the first stratigraphically well-documented Pliocene record of this species in Italy, the previous discoveries dating back to the 19th century or the beginning of the 20th century, hence lacking stratigraphic control. According to the obtained results, it is possible to assess the occurrence of <em>P. megarhinus</em> during the earliest Pliocene in Italy as well as to confirm the long-lasting persistence of this species, whose fossil record covers a timespan between 6.7 Ma and 3.5 Ma. During that time, <em>P. megarhinus</em> did seemingly undergo a trend of body mass reduction.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"88 ","pages":"Pages 197-204"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141694498","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}

引用次数: 0

A new enantiornithine (Aves: Ornithothoraces) from the Lower Cretaceous Xiagou Formation with unusually short pubes 下白垩统下沟组一种新的异鸟目动物（鸟类目：鸟胸目），短毛异常

IF 1.6 4区地球科学

Geobios Pub Date : 2025-01-17 DOI: 10.1016/j.geobios.2024.11.003

Jingmai K. O’Connor , Jessie Atterholt , Alexander D. Clark , Linqi Zhou , Cuo Peng , Xiaoqin Zhang , Hailu You

{"title":"A new enantiornithine (Aves: Ornithothoraces) from the Lower Cretaceous Xiagou Formation with unusually short pubes","authors":"Jingmai K. O’Connor , Jessie Atterholt , Alexander D. Clark , Linqi Zhou , Cuo Peng , Xiaoqin Zhang , Hailu You","doi":"10.1016/j.geobios.2024.11.003","DOIUrl":"10.1016/j.geobios.2024.11.003","url":null,"abstract":"<div><div>We describe a partial skeleton of an enantiornithine from the Changma locality of the Lower Cretaceous Xiagou Formation in northwestern China. The specimen is tentatively interpreted as a gastric pellet. The specimen preserves an unusually short pubis that is subequal in length to the ischium, an autapomorphy among enantiornithines, justifying erection of a new taxon, <em>Novavis pubisculata</em> nov. gen., nov. sp. The abbreviated length of the pubis suggests that the abdominal cavity in this species was proportionately shorter than in all other known enantiornithines. Although several muscles attach to the pubis, the mm. <em>pubocaudalis internus</em> and <em>externus</em> were probably the most functionally impacted by the increased distance between the pubes and caudal vertebrae and subsequent elongation of these muscles. In crown avians this would result in a decrease in the contraction speed of these muscles, which play a role in tail fanning and are thus important for flight during take-off and landing. Although the underlying function of the short pubis and changes in the size of the abdominal cavity are unknown, the widespread absence of aerodynamic tail musculature and plumage in enantiornithines may have relaxed pressures constraining the length of these muscles, such that elongation of these muscles through a shortened pubis was not detrimental to the aerodynamic abilities of these birds.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"90 ","pages":"Pages 123-131"},"PeriodicalIF":1.6,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143928090","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}

引用次数: 0

Occurrence of the trace fossil Hillichnus in Upper Cretaceous deposits in association with dinosaur footprints: A case from the Torotoro National Park in Bolivia 上白垩纪沉积物中与恐龙足迹相关的微量化石Hillichnus的出现：来自玻利维亚托罗托罗国家公园的一个案例

IF 1.6 4区地球科学

Geobios Pub Date : 2024-12-01 DOI: 10.1016/j.geobios.2024.08.018

Francisco J. Rodríguez-Tovar , Raúl Esperante , Roberto E. Biaggi , Nelson A. Llempen

{"title":"Occurrence of the trace fossil Hillichnus in Upper Cretaceous deposits in association with dinosaur footprints: A case from the Torotoro National Park in Bolivia","authors":"Francisco J. Rodríguez-Tovar , Raúl Esperante , Roberto E. Biaggi , Nelson A. Llempen","doi":"10.1016/j.geobios.2024.08.018","DOIUrl":"10.1016/j.geobios.2024.08.018","url":null,"abstract":"<div><div>We present here the occurrence of the scarce, complex trace fossil <em>Hillichnus</em> associated with abundant theropod tracks and locally bird tracks at the Carreras Pampa dinosaur track site in the Torotoro National Park (TTNP), Bolivia. <em>Hillichnus</em> is a complex trace fossil produced by tellinacean bivalves, revealing various behaviours including locomotion, feeding, respiration and defecation. The specimens occur on the surface of a grainstone bed in the Maastrichtian El Molino Formation, characterized by the presence of low-angle planar cross-stratification, ripple cross-lamination, wavy or convoluted lamination and wave ripples. The associated invertebrate trace fossil assemblage mainly consists of superficial sinuous structures of variable size, a variety of holes (vertical burrows?), and radial/rosette trace fossils. The associated vertebrate trace fossil assemblage consists of theropod footprints, many well-preserved theropod swim traces arranged in trackways and bird tracks. The record of <em>Hillichnus</em>, associated to the ichnological assemblage and to sedimentological data, suggests a marginal-marine setting with freshwater influence in shallow water for the Upper Cretaceous of the El Molino Formation at the Carreras Pampa area. Local stratigraphic successions suggest both marine and lacustrine/fluvial environments. The track-bearing bed shows evidence of exposure and is covered by sediments deposited in deeper water. The occurrence of <em>Hillichnus</em> in Bolivia, in association with dinosaur tracks on the same bed, has relevant implications for the characterization of paleoenvironmental conditions during the production of dinosaur tracks at the Carreras Pampa site in the TTNP.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"87 ","pages":"Pages 71-79"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143175245","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}

引用次数: 0

New Chinese Jurassic damsel-dragonflies of the families Paragonophlebiidae, Selenothemistidae and Isophlebiidae (Odonata, Epiproctophora) from the Jurassic Ordos Basin of NW China 鄂尔多斯盆地侏罗系新侏罗系绢蜻蜓科、绢蜻蜓科和等绢蜻蜓科（绢蜻蜓目、绢蜻蜓目）

IF 1.6 4区地球科学

Geobios Pub Date : 2024-12-01 DOI: 10.1016/j.geobios.2024.08.014

André Nel , Minmin Xu , Yehao Wang , Xiangbo Song , Jian Gao , Gaozhe Ji , Diying Huang

引用次数: 0

Sauropterygian remains from the Middle Triassic of Araif El-Naqa as the first identification of Simosauridae (Eosauropterygia) in Egypt Araif El-Naqa地区中三叠世的蜥脚类化石是埃及首次发现的Simosauridae （eosaurpterygia）化石

IF 1.6 4区地球科学

Geobios Pub Date : 2024-12-01 DOI: 10.1016/j.geobios.2024.08.015

Alberto Cabezuelo-Hernández, Carlos de Miguel Chaves, Adán Pérez-García

{"title":"Sauropterygian remains from the Middle Triassic of Araif El-Naqa as the first identification of Simosauridae (Eosauropterygia) in Egypt","authors":"Alberto Cabezuelo-Hernández, Carlos de Miguel Chaves, Adán Pérez-García","doi":"10.1016/j.geobios.2024.08.015","DOIUrl":"10.1016/j.geobios.2024.08.015","url":null,"abstract":"<div><div>Simosauridae is a Triassic eosauropterygian clade restricted to the western Paleotethys. It is known by relatively abundant cranial and postcranial elements coming mostly from European localities, where the type species, <em>Simosaurus gaillardoti</em>, from the Ladinian (Middle Triassic) of France and Germany, and the recently defined <em>Paludidraco multidentatus</em>, from the Carnian (Late Triassic) of Spain are known, in addition to several simosaurids of undetermined generic and specific attribution. By contrast, it is poorly represented in the Middle East, being known from both Israel and Saudi Arabia by scarce remains of uncertain systematic attribution. The Middle Triassic deposits of Araif El-Naqa, in Egypt, have yielded several sauropterygian remains, so far attributable to the placodont taxa <em>Psephosauriscus sinaiticus</em> and <em>Psephosauriscus rhombifer</em>, as well as to indeterminate nothosaurs. Here, we describe several unpublished vertebral sauropterygian remains from Araif El-Naqa, identifying the presence of the clade Simosauridae for the first time in Egypt and the first simosaurid vertebral remains from the Eastern Mediterranean.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"87 ","pages":"Pages 1-7"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143175754","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}

引用次数: 0

New material of the small raoellid artiodactyl Metkatius kashmiriensis Kumar and Sahni, 1985 (Mammalia) from the middle Eocene of the Kalakot area, Rajouri District, Jammu and Kashmir, India 印度查谟和克什米尔Rajouri地区Kalakot地区小型raoelid偶蹄类Metkatius kashmiriensis Kumar和Sahni， 1985（哺乳类）的新材料

IF 1.6 4区地球科学

Geobios Pub Date : 2024-12-01 DOI: 10.1016/j.geobios.2024.08.017

Romain Weppe , Mohd Waqas , Rajendra S. Rana , Thierry Smith

{"title":"New material of the small raoellid artiodactyl Metkatius kashmiriensis Kumar and Sahni, 1985 (Mammalia) from the middle Eocene of the Kalakot area, Rajouri District, Jammu and Kashmir, India","authors":"Romain Weppe , Mohd Waqas , Rajendra S. Rana , Thierry Smith","doi":"10.1016/j.geobios.2024.08.017","DOIUrl":"10.1016/j.geobios.2024.08.017","url":null,"abstract":"<div><div>New material of the small raoellid artiodactyl <em>Metkatius kashmiriensis</em> is reported from the middle Eocene of the Upper Subathu Formation in the Kalakot area, Jammu and Kashmir, northwest Himalaya, India. The fossil material consists of numerous mandibular and maxillary fragments and isolated teeth, mainly belonging to juvenile specimens. It documents the poorly known dental morphology of <em>M</em>. <em>kashmiriensis</em> and provides an overview of its intraspecific variation, allowing to redefine its diagnosis. <em>M. kashmiriensis</em> is characterized by a particularly small size compared with other raoellid species, and by bunodont molars with moderately marked transverse lophs. The M/1–2 are much longer than wide and display characters similar to those of <em>Rajouria gunnelli</em>, such as the presence of a small paraconid and a mesial mesiostylid. The P/4 bears distally a small hypoconid, which appears to be unique in Raoellidae. The description of the new material also allows to document the poorly known morphology of the deciduous teeth of raoellids. The DP2/ is reported for the first time, and the DP/4 of <em>M</em>. <em>kashmiriensis</em> shows a morphology different from that of <em>Indohyus</em>, with the absence of mesial basin anterior to the paraconid and the primoconid. Contrary to what has recently been proposed, these results confirm that <em>M</em>. <em>kashmiriensis</em> is a valid species and not a synonym of <em>Indohyus indirae</em>, and highlight the great morphological diversity present within the Raoellidae during the middle Eocene in the Indian subcontinent.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"87 ","pages":"Pages 81-90"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143175247","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}

引用次数: 0

The palaeobiogeographic significance of the Nötsch area (Austria) during the Middle and Late Mississippian based on rugose corals 基于红珊瑚的Nötsch地区（奥地利）密西西比中晚期的古生物地理意义

IF 1.6 4区地球科学

Geobios Pub Date : 2024-12-01 DOI: 10.1016/j.geobios.2024.09.002

Isabel Rodríguez-Castro , Herbert Kabon , Sergio Rodríguez

{"title":"The palaeobiogeographic significance of the Nötsch area (Austria) during the Middle and Late Mississippian based on rugose corals","authors":"Isabel Rodríguez-Castro , Herbert Kabon , Sergio Rodríguez","doi":"10.1016/j.geobios.2024.09.002","DOIUrl":"10.1016/j.geobios.2024.09.002","url":null,"abstract":"<div><div>The Carboniferous of Nötsch (South Austria) is composed of three formations: the Erlachgraben Formation, the Badstub Breccia, and the Nötsch Formation, that yielded abundant corals, several of them being new for that region. The assemblage is composed of 11 rugose coral species (<em>Siphonophyllia</em> sp., <em>Pseudozaphrentoides juddi</em>, <em>Lublinophyllum</em>? sp., <em>Dibunophyllum bipartitum</em>, <em>Arachnolasma cylindrica</em>, <em>Palaeosmilia murchisoni</em>, <em>Aulokoninckophyllum carinatum</em>, <em>Siphonodendron martini</em>, <em>Diphyphyllum furcatum</em>, <em>Solenodendron furcatum</em>, and <em>Solenodendron horsfieldi</em>), two tabulate species (<em>Multithecopora</em> sp. and <em>Palaeacis</em> sp.) and one heterocoral species (<em>Hexaphyllia mirabilis</em>). In addition, five rugosans that are not in our collection have been identified by previous authors (<em>Clisiophyllum</em> sp., <em>Pseudozaphrentoides</em> sp., <em>Caninia</em> sp., “<em>Palaeosmilia isae</em>”, and <em>Lophophyllidium</em> sp.). The rugose and tabulate species are described and figured. A palaeobiogeographic analysis comparing the Mississippian assemblages from Nötsch and other Austrian outcrops with other domains in Central Europe has been performed using hierarchical clustering with Simpson and Dice similarity indices. The statistical comparison of the rugose coral assemblages at the genus level allows a better perception of the distribution of the shallow water carbonate platforms in that part of the Western Palaeotethys during the Visean and Serpukhovian. The results are incorporated in a schematic palaeogeographical map of the studied area for the late Visean.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"87 ","pages":"Pages 57-70"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143175246","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}

引用次数: 0

The purported record of an epibiontic rhabdopleurid in the early Ordovician Fezouata biota of Morocco, with a discussion about benthic pterobranchs (Hemichordata) in the Lagerstätte 摩洛哥早奥陶世Fezouata生物群中一个拟表生横纹肌类的记录，并讨论Lagerstätte底栖翼类（Hemichordata）

IF 1.6 4区地球科学

Geobios Pub Date : 2024-12-01 DOI: 10.1016/j.geobios.2024.09.001

Jörg Maletz , Juan Carlos Gutiérrez-Marco

{"title":"The purported record of an epibiontic rhabdopleurid in the early Ordovician Fezouata biota of Morocco, with a discussion about benthic pterobranchs (Hemichordata) in the Lagerstätte","authors":"Jörg Maletz , Juan Carlos Gutiérrez-Marco","doi":"10.1016/j.geobios.2024.09.001","DOIUrl":"10.1016/j.geobios.2024.09.001","url":null,"abstract":"<div><div>The recent record of extremely rare rhabdopleurid graptolites with a supposed epibiontic life style in the Fezouata biota has to be rejected, as the specimens indicate an epibenthic growth on a shell fragment lying on the sea bottom. In absence of morphological data that support a truly colonial development on these encrusters, it cannot be ruled out that the specimens may alternatively represent the pseudo-colonial tubaria of cephalodiscid-like pterobranchs. The interpretation of the presence of benthic graptolites (class Pterobranchia; subclass Graptolithina) from the Fezouata Shale biota of Morocco provides us with some serious problems. Their life style as benthic or epibenthic organisms living on firm substrates and hardgrounds makes it difficult for them to be preserved in these highly fossiliferous, originally ‘soupy’ soft sediments of the Fezouata Shale, unless they are transported and covered by sediment subsequently. The graptolite record of the Fezouata biota appears to be restricted to planktic forms of Graptoloidea: the review of the few benthic dendroids so far cited for the Lagerstätte resulted in the identification of the rare planktic dendroid genus <em>Calyxdendrum</em>. The problematic species <em>Webbyites felix</em> may represent a hydrozoan (Cnidaria) rather than a benthic graptolite.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"87 ","pages":"Pages 25-35"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143174155","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}

引用次数: 0

Improved paired light and scanning electron microscope imaging technique for identifying nannofossils in Arctic sediments 北极沉积物中纳米化石鉴定的改进配对光和扫描电镜成像技术

IF 1.6 4区地球科学

Geobios Pub Date : 2024-12-01 DOI: 10.1016/j.geobios.2024.08.016

Mohammad J. Razmjooei , Matt O’Regan

{"title":"Improved paired light and scanning electron microscope imaging technique for identifying nannofossils in Arctic sediments","authors":"Mohammad J. Razmjooei , Matt O’Regan","doi":"10.1016/j.geobios.2024.08.016","DOIUrl":"10.1016/j.geobios.2024.08.016","url":null,"abstract":"<div><div>Calcareous nannofossils provide biostratigraphic age-markers for Pleistocene Arctic Ocean sediments. However, Pleistocene Arctic sediments are dominated by fine-grained terrigenous material, and commonly contain rare and poorly preserved coccolith specimens that can be difficult to identify under the light microscope (LM). Using paired observations of the same specimens under LM and a scanning electron microscope (SEM), we recently discovered that poorly preserved Noelaerhabdaceae specimens that cannot be identified at the species level were previously classified as <em>Gephyrocapsa huxleyi</em> using LM observations alone. Moreover, the visual resemblance under LM between <em>G. huxleyi</em> and another Quaternary marker species, <em>Pseudoemiliania lacunosa</em>, also led to occasional misdiagnosis. Given the importance of <em>G. huxleyi</em> and <em>P. lacunosa</em> for stratigraphic age control, this has potentially profound implications for our understanding of the paleoceanographic history of the Arctic, and also other ocean basins. This study focuses on challenges met in improving and applying the paired LM-SEM technique for observation of the same nannofossil specimens, and on its subsequent adjustments in the case of Quaternary Arctic sediments, which often contain low abundances of calcareous micro- and nannofossils. Moreover, we review morphological aspects and discuss potential difficulties in unambiguously identifying <em>G. huxleyi</em>, <em>P. lacunosa</em> and <em>Gephyrocapsa</em> under LM and illustrate the need of integrating SEM images – which can be difficult to obtain in low-diversity assemblage sediments dominated by silt and clay.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"87 ","pages":"Pages 45-56"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143175244","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}

引用次数: 0

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