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 purported record of an epibiontic rhabdopleurid in the early Ordovician Fezouata biota of Morocco, with a discussion about benthic pterobranchs (Hemichordata) in the Lagerstätte

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

The palaeobiogeographic significance of the Nötsch area (Austria) during the Middle and Late Mississippian based on rugose corals

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

Improved paired light and scanning electron microscope imaging technique for identifying nannofossils in Arctic sediments

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

A spatangoid echinoid assemblage from the Gutingkeng Formation (Early Pleistocene) of Taiwan and its paleoenvironmental and geological implications

IF 1.6 4区地球科学

Geobios Pub Date : 2024-12-01 DOI: 10.1016/j.geobios.2024.09.003

Chia-Hsin Hsu , Jih-Pai Lin , Chien-Hsiang Lin

{"title":"A spatangoid echinoid assemblage from the Gutingkeng Formation (Early Pleistocene) of Taiwan and its paleoenvironmental and geological implications","authors":"Chia-Hsin Hsu , Jih-Pai Lin , Chien-Hsiang Lin","doi":"10.1016/j.geobios.2024.09.003","DOIUrl":"10.1016/j.geobios.2024.09.003","url":null,"abstract":"<div><div>Heart urchins (Echinoidea: Spatangoida) collectively represent a highly diverse group of echinoids with abundant global fossil and extant records. Despite their wide distribution, the preservation challenges associated with their delicate and thin tests have led to limited comprehensive studies of this fossil group in Taiwan. Here, we report a new spatangoid echinoid assemblage from the Early Pleistocene part of the Gutingkeng Formation. Despite the inherent fragility and pronounced deformations in the studied specimens, the preserved key diagnostic characteristics (pore pairs in ambulacrum III and oral plating) indicate most of the fossil echinoids belong to genera <em>Schizaster</em> and <em>Brissopsis</em>. Moreover, based on detailed taphonomic and functional morphological examination, the paleoenvironment of the assemblage is interpreted as a low-energy, fine-grained soft substrate in a deeper shallow-water setting. Furthermore, this assemblage shares a high similarity with Assemblage 3 at the S’Archittu-Cajaragas section in the Miocene of Sardinia, supporting the notion that echinoids are excellent paleoenvironmental indicators, as similar echinoid faunas can be found across continents when environmental conditions are similar. On the other hand, the temporal and geographical distribution of <em>Schizaster</em>-rich echinoid assemblages in Taiwan may be correlated with the Cenozoic orogeny history of Taiwan.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"87 ","pages":"Pages 9-23"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143175753","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

Tsuga leaves from the Neogene Baoshan Basin in southwest China and their palaeoecological implications 中国西南新近纪宝山盆地出土的簇叶及其古生态学意义

IF 1.6 4区地球科学

Geobios Pub Date : 2024-10-01 DOI: 10.1016/j.geobios.2024.08.004

Hao-Ran Zong , Jin-Jin Hu , Nian Wang , Yong-Jiang Huang

{"title":"Tsuga leaves from the Neogene Baoshan Basin in southwest China and their palaeoecological implications","authors":"Hao-Ran Zong , Jin-Jin Hu , Nian Wang , Yong-Jiang Huang","doi":"10.1016/j.geobios.2024.08.004","DOIUrl":"10.1016/j.geobios.2024.08.004","url":null,"abstract":"<div><div><em>Tsuga</em> (Endl.) Carrière (Pinaceae) has a rich fossil record represented by pollen, leaves, wood and seed cones. Although fossil leaves of the genus have been widely documented, most of them have not been examined microscopically, which may limit their taxonomic resolution. In this study, three-dimensionally preserved leaves and leaf fragments of <em>Tsuga</em> from the Neogene (latest Miocene to Pliocene) Baoshan Basin in western Yunnan, southwest China, were examined both morphologically and micromorphologically. The fossil leaves are characterized by flattened and bifacial shape, round to obtuse apex and petiolate base, adaxially sunken and abaxially elevated midvein, adaxial surface without stomata and with elongated, smooth-margined epidermal cells, and abaxial surface with two stomatal bands along the midvein, each stomatal band consisting of 6–8 longitudinal stomatal lines. Based on comparisons with extant species of the genus, we found that the fossil leaves show the closest affinity to <em>Tsuga dumosa</em> (D. Don) Eichler, an extant species growing in the modern western Yunnan. As modern species of <em>Tsuga</em> prefer humid conditions, our fossil find suggests a humid climate in the Baoshan Basin at the time of fossil deposition, probably due to the influence of the Indian summer monsoon from the southwest. This is consistent with previous results of quantitative palaeoclimate reconstructions using spore/pollen fossil assemblages. Our study provides new fossil evidence for the origin of modern conifer diversity in southwest China. It highlights the importance of microscopic studies in the taxonomic resolution of fossil leaves of Pinaceae.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"86 ","pages":"Pages 107-117"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578306","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 review of the Late Miocene herpetofauna of the Keinar locality of Moldova 摩尔多瓦 Keinar 地区晚中新世动物群回顾

IF 1.6 4区地球科学

Geobios Pub Date : 2024-10-01 DOI: 10.1016/j.geobios.2024.08.005

Elena Syromyatnikova , Oleg Redkozubov

引用次数: 0

A rare ‘flat-headed’ pachycephalosaur (Dinosauria: Pachycephalosauridae) from West Texas, USA, with morphometric and heterochronic considerations 来自美国西得克萨斯州的罕见 "平头 "棘头龙（恐龙亚目：棘头龙科）及其形态计量学和异时性考量

IF 1.6 4区地球科学

Geobios Pub Date : 2024-10-01 DOI: 10.1016/j.geobios.2024.08.006

Steven L. Wick , Thomas M. Lehman

{"title":"A rare ‘flat-headed’ pachycephalosaur (Dinosauria: Pachycephalosauridae) from West Texas, USA, with morphometric and heterochronic considerations","authors":"Steven L. Wick , Thomas M. Lehman","doi":"10.1016/j.geobios.2024.08.006","DOIUrl":"10.1016/j.geobios.2024.08.006","url":null,"abstract":"<div><div>A juvenile pachycephalosaur frontal from the upper Aguja Formation (Late Cretaceous: middle Campanian) of West Texas, USA is unusually thin dorsoventrally, even compared to ‘flat’ frontals of young individuals pertaining to other pachycephalosaur taxa. The specimen is most comparable morphologically and morphometrically to <em>Stegoceras validum</em>. However, it is much thinner than any ‘juvenile’ example of that species, and also differs in the elongate form and radial arrangement of the surficial tubercles, as well as occurrence of radial grooves along the lateral margins of the bone. Such differences are unlikely a reflection of intraspecific variation. Instead, the Aguja specimen likely represents a previously unknown juvenile semaphoront from the southern Western Interior, referred herein to <em>Stegoceras</em> sp. and likely extends the distribution of this widespread Campanian genus. A morphometric evaluation suggests that the holotype specimen of <em>Texacephale langstoni</em>, also from the Aguja Formation, is probably an adult semaphoront of <em>Stegoceras.</em> However, both specimens represent different ontogenetic stages with dissimilar morphologies and so their potential conspecifity remains equivocal. The new Aguja specimen described herein likely represents a ‘paedomorphic’ Campanian pachycephalosaur – one where the onset of doming is displaced until well into ontogeny – a heterochronic attribute <em>Stegoceras</em> sp. shares with <em>S. validum</em> and <em>Pachycephalosaurus wyomingensis.</em> Where an adequate ontogenetic sample is available for comparison, other pachycephalosaur taxa do not seem to exhibit a similar growth progression, and so this appears to be a significant taxonomic characteristic. That some pachycephalosaurs delayed doming of the skull roof during growth is enigmatic, but it may have been an expression of sexual dimorphism, an aid in species recognition, or a response to harsh environmental conditions.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"86 ","pages":"Pages 89-106"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578309","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

Early Pliocene Spalacinae from the locality of Afşar, western Turkey 来自土耳其西部阿夫沙尔地区的早上新世 Spalacinae

IF 1.6 4区地球科学

Geobios Pub Date : 2024-10-01 DOI: 10.1016/j.geobios.2024.08.007

Panagiotis Skandalos , Fatma Arzu Demirel , Mehmet Cihat Alçiçek , Serdar Mayda , Lars W. van den Hoek Ostende

引用次数: 0

Biochronostratigraphy and palaeobiogeography of Echioceratidae (Ammonitina) from the Raricostatum Zone (Aplanatum Subzone) in NW Iberia 伊比利亚西北部 Raricostatum 区（Aplanatum 亚区）Echioceratidae（Amonitina）的生物时层图和古生物地理学

IF 1.6 4区地球科学

Geobios Pub Date : 2024-10-01 DOI: 10.1016/j.geobios.2024.08.002

Íñigo Vitón , María José Comas-Rengifo , Luís V. Duarte , Antonio Goy

{"title":"Biochronostratigraphy and palaeobiogeography of Echioceratidae (Ammonitina) from the Raricostatum Zone (Aplanatum Subzone) in NW Iberia","authors":"Íñigo Vitón , María José Comas-Rengifo , Luís V. Duarte , Antonio Goy","doi":"10.1016/j.geobios.2024.08.002","DOIUrl":"10.1016/j.geobios.2024.08.002","url":null,"abstract":"<div><div>This paper examines the uppermost Sinemurian and lowermost Pliensbachian ammonite fauna recorded in NW Iberia with a special focus on Echioceratidae from the Aplanatum Subzone. In total, 852 specimens have been collected bed-by-bed from five reference sections from the Asturian, Basque-Cantabrian, and Lusitanian basins. Echioceratidae, namely <em>Paltechioceras</em> genus, represent 86.2% of the sample, Polymorphitidae (<em>Leptonotoceras</em> genus) the 10%, and less than 4% of the specimens are Eoderoceratidae, Phricodoceratidae, or Oxynoticeratidae. This study describes five species of <em>Paltechioceras</em>, namely <em>P. tardecrescens</em>, <em>P. oosteri</em>, <em>P. recticostatum</em>, <em>P. elicitum</em>, and <em>P. romanicum</em>. They allow a biochronostratigraphic division for the studied basins and its worldwide correlation. One of the species, <em>P. romanicum</em>, is the latest one registered in all the studied sections, occurring directly below the Sinemurian–Pliensbachian boundary. The disappearance of this widely distributed species marks the echioceratids extinction. This work reviews the global events described around the Sinemurian–Pliensbachian transition (the Sinemurian–Pliensbachian boundary event). Finally, we present a palaeobiogeographical analysis of the <em>Paltechioceras</em> species described, giving more information to discuss the opening of the Hispanic Corridor during the late Sinemurian.</div></div>","PeriodicalId":55116,"journal":{"name":"Geobios","volume":"86 ","pages":"Pages 65-87"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578308","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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