Pub Date : 2024-11-22DOI: 10.1016/j.revpalbo.2024.105248
Gamal E.B. El Ghazali
Intraspecific structural variations in pollen grains are widespread in angiosperms. The aims of the present review are to track down intraspecific variability in various pollen morphological features, and to evaluate their taxonomic significance in defining species boundaries. Shape of pollen grains, sculptures, aperture types and numbers, muri textures, presence/absence of opercula, folded ectexines and pollen corpus (in bisaccate pollen grains) were encountered to exhibit intraspecific variations in the various taxa examined. These structural characteristics were recognized to be associated with variations of evolutionary effects, in the spatial arrangements and structural diversity of the styles (heterostyly, enantiostyly, stigma-height dimorphism, inverostyly), anthers (heteranthery), stigma textures, and the reproductive (breeding) systems (androdioecy, dioecy, andromonoecy) of the flowers. Other internal (polyploidy) and external factors (environmental) linked with structural intraspecific pollen variations were also considered. In order to characterize intraspecific boundaries and to test the credibility of these characters, various statistical tools were surveyed to identify characters of diagnostic taxonomic values.
{"title":"Intraspecific pollen morphological variations and their importance to characterize species boundaries: A review.","authors":"Gamal E.B. El Ghazali","doi":"10.1016/j.revpalbo.2024.105248","DOIUrl":"10.1016/j.revpalbo.2024.105248","url":null,"abstract":"<div><div>Intraspecific structural variations in pollen grains are widespread in angiosperms. The aims of the present review are to track down intraspecific variability in various pollen morphological features, and to evaluate their taxonomic significance in defining species boundaries. Shape of pollen grains, sculptures, aperture types and numbers, muri textures, presence/absence of opercula, folded ectexines and pollen corpus (in bisaccate pollen grains) were encountered to exhibit intraspecific variations in the various taxa examined. These structural characteristics were recognized to be associated with variations of evolutionary effects, in the spatial arrangements and structural diversity of the styles (heterostyly, enantiostyly, stigma-height dimorphism, inverostyly), anthers (heteranthery), stigma textures, and the reproductive (breeding) systems (androdioecy, dioecy, andromonoecy) of the flowers. Other internal (polyploidy) and external factors (environmental) linked with structural intraspecific pollen variations were also considered. In order to characterize intraspecific boundaries and to test the credibility of these characters, various statistical tools were surveyed to identify characters of diagnostic taxonomic values.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"333 ","pages":"Article 105248"},"PeriodicalIF":1.7,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142721915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-17DOI: 10.1016/j.revpalbo.2024.105239
Giuseppa Forte , Roberta Branz , Nereo Preto , Evelyn Kustatscher
Conifers, the most successful group of Permian gymnosperms, dominate the famous Bletterbach (Dolomites, NE-Italy) plant fossil assemblage, a highly diverse and well-documented late Permian (Lopingian) flora. An integrated analysis of morphology, cuticles and isotope geochemistry was carried out on approximately 50 conifer shoots across five genera (Ortiseia, Majonica, Dolomitia, Pseudovoltzia and Quadrocladus) and eight species, including three (Pseudovoltzia sjerpii, Quadrocladus solmsii, Quadrocladus cf. orobiformis) described for the first time from Bletterbach. Taxon-specific carbon isotope analyses reveal intra-specific and/or intra-generic variability, identifying a unique geochemical composition for Majonica alpina, which may reflect a possible species-specific geochemical signature or adaptation to particular environmental conditions. The isotopic differences observed between leaves and axes indicate the preservation of distinct isotopic ratios in photosynthetic versus heterotrophic tissues, underscoring the importance of sampling multiple plant parts to accurately capture individual and taxonomic isotopic variability. The study of stable isotopes of organic carbon on well-preserved plant remains is enhanced the paleoenvironmental reconstruction of the Bletterbach flora.
{"title":"Morphology, epidermal features and δ13C signature of Lopingian (late Permian) conifers","authors":"Giuseppa Forte , Roberta Branz , Nereo Preto , Evelyn Kustatscher","doi":"10.1016/j.revpalbo.2024.105239","DOIUrl":"10.1016/j.revpalbo.2024.105239","url":null,"abstract":"<div><div>Conifers, the most successful group of Permian gymnosperms, dominate the famous Bletterbach (Dolomites, NE-Italy) plant fossil assemblage, a highly diverse and well-documented late Permian (Lopingian) flora. An integrated analysis of morphology, cuticles and isotope geochemistry was carried out on approximately 50 conifer shoots across five genera (<em>Ortiseia</em>, <em>Majonica, Dolomitia</em>, <em>Pseudovoltzia</em> and <em>Quadrocladus</em>) and eight species, including three (<em>Pseudovoltzia sjerpii</em>, <em>Quadrocladus solmsii</em>, <em>Quadrocladus</em> cf. <em>orobiformis</em>) described for the first time from Bletterbach. Taxon-specific carbon isotope analyses reveal intra-specific and/or intra-generic variability, identifying a unique geochemical composition for <em>Majonica alpina</em>, which may reflect a possible species-specific geochemical signature or adaptation to particular environmental conditions. The isotopic differences observed between leaves and axes indicate the preservation of distinct isotopic ratios in photosynthetic versus heterotrophic tissues, underscoring the importance of sampling multiple plant parts to accurately capture individual and taxonomic isotopic variability. The study of stable isotopes of organic carbon on well-preserved plant remains is enhanced the paleoenvironmental reconstruction of the Bletterbach flora.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"333 ","pages":"Article 105239"},"PeriodicalIF":1.7,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142721914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.revpalbo.2024.105240
Colin J. Courtney Mustaphi , Sandra O. Camara-Brugger , Anneli Ekblom , Linus Munishi , Rebecca Kariuki , Anna Shoemaker , Paul Lane , Rob Marchant
The analysis of fossil pollen from sediments is used to understand past vegetation and land cover variability. The observations of multiporate Poaceae pollen from sediments have received little attention in the literature and causes and rates of occurrence have few estimates, and the rates observed in the sediments are much lower than estimates observed from modern plants in Asia. Pollen analysis of the uppermost sediments from Speke Gulf, Lake Victoria, eastern Africa, showed relative abundances of Poaceae between 65 and 75% during the past centuries. A total of 19 of the ∼ 11,000 Poaceae pollen grains observed had conspicuous morphological variations and were documented. More consistent presence of abnormal grains occurred since the mid twentieth century, at the same time of increased anthropogenic environmental stressors. Multiporate pollen grains of Poaceae have been previously observed in Asia, South America, and northern Africa, predominantly in the Panicoideae subfamily. Morphological variations may present an added challenge for automated pollen identification techniques and descriptions of fossil pollen.
{"title":"Multiporate Poaceae pollen grains observed in the recent fossil record from the Greater Serengeti Ecosystem and Lake Victoria region","authors":"Colin J. Courtney Mustaphi , Sandra O. Camara-Brugger , Anneli Ekblom , Linus Munishi , Rebecca Kariuki , Anna Shoemaker , Paul Lane , Rob Marchant","doi":"10.1016/j.revpalbo.2024.105240","DOIUrl":"10.1016/j.revpalbo.2024.105240","url":null,"abstract":"<div><div>The analysis of fossil pollen from sediments is used to understand past vegetation and land cover variability. The observations of multiporate Poaceae pollen from sediments have received little attention in the literature and causes and rates of occurrence have few estimates, and the rates observed in the sediments are much lower than estimates observed from modern plants in Asia. Pollen analysis of the uppermost sediments from Speke Gulf, Lake Victoria, eastern Africa, showed relative abundances of Poaceae between 65 and 75% during the past centuries. A total of 19 of the ∼<!--> <!-->11,000 Poaceae pollen grains observed had conspicuous morphological variations and were documented. More consistent presence of abnormal grains occurred since the mid twentieth century, at the same time of increased anthropogenic environmental stressors. Multiporate pollen grains of Poaceae have been previously observed in Asia, South America, and northern Africa, predominantly in the Panicoideae subfamily. Morphological variations may present an added challenge for automated pollen identification techniques and descriptions of fossil pollen.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"333 ","pages":"Article 105240"},"PeriodicalIF":1.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1016/j.revpalbo.2024.105237
A.-M. Lézine , B. Turcq , T. Desjardins , M. Mandeng-Yogo , F. Cetin , B. Tchiengué , G. Achoundong
This paper presents the pollen, microcharcoal and geochemical data generated by a sediment core extracted from Lake Child in the Manengouba massif of Cameroon (MAN-01: 5.02996 N, 9.822910E; 1948 m asl) covering the time interval between 15.4 and 9.6 ka. With an exceptional sedimentation rate of up to 13 cm per year, this record represents the highest resolution of the environmental changes that took place in the highlands of equatorial Atlantic Africa during the last deglaciation. Our study shows (1) that the Younger Dryas (YD) dry event consisted of two distinct phases: a dry phase between 12.8 and 11.7 ka followed by a wetter and colder phase between 11.7 and 11.3 ka; (2) that the Afromontane forest elements that were present during the last glacial period were replaced by sub-montane forest elements during the Holocene; (3) that vegetation and the hydrological environment have not always evolved in parallel: this was particularly the case at the YD/Holocene transition when the abrupt shift in hydrological conditions contrasted with the gradual spread of forests.
本文介绍了从喀麦隆马嫩古巴山丘（MAN-01：北纬 5.02996，东经 9.822910；海拔 1948 米）的 Child 湖提取的沉积岩芯所产生的花粉、微炭和地球化学数据，时间跨度为 15.4 ka 至 9.6 ka。该记录以每年高达 13 厘米的超常沉积速率，代表了最后一次脱冰期非洲赤道大西洋高地环境变化的最高分辨率。我们的研究表明：（1）年轻干旱期（YD）的干旱事件由两个不同的阶段组成：在 12.8 ka 到 11.7 ka 之间的干旱阶段，随后是 11.7 ka 到 11.3 ka 之间的湿润和寒冷阶段；（2）在 11.7 ka 到 11.3 ka 之间的湿润和寒冷阶段。(3) 植被与水文环境并不总是同步演化的：在 YD 与全新世过渡时期，水文条件的突然转变与森林的逐渐扩展形成鲜明对比，情况尤其如此。
{"title":"Impact of the Younger Dryas dry event on equatorial forest ecosystems: Insight from Lake Child, Manengouba crater, Cameroon","authors":"A.-M. Lézine , B. Turcq , T. Desjardins , M. Mandeng-Yogo , F. Cetin , B. Tchiengué , G. Achoundong","doi":"10.1016/j.revpalbo.2024.105237","DOIUrl":"10.1016/j.revpalbo.2024.105237","url":null,"abstract":"<div><div>This paper presents the pollen, microcharcoal and geochemical data generated by a sediment core extracted from Lake Child in the Manengouba massif of Cameroon (MAN-01: 5.02996 N, 9.822910E; 1948 m asl) covering the time interval between 15.4 and 9.6 ka. With an exceptional sedimentation rate of up to 13 cm per year, this record represents the highest resolution of the environmental changes that took place in the highlands of equatorial Atlantic Africa during the last deglaciation. Our study shows (1) that the Younger Dryas (YD) dry event consisted of two distinct phases: a dry phase between 12.8 and 11.7 ka followed by a wetter and colder phase between 11.7 and 11.3 ka; (2) that the Afromontane forest elements that were present during the last glacial period were replaced by sub-montane forest elements during the Holocene; (3) that vegetation and the hydrological environment have not always evolved in parallel: this was particularly the case at the YD/Holocene transition when the abrupt shift in hydrological conditions contrasted with the gradual spread of forests.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"332 ","pages":"Article 105237"},"PeriodicalIF":1.7,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The article presents the results of cytoembryological research of the structure of fossil seeds in coniferous plants Alapaja cf. uralensis (Cupressaceae) from the Cenomanian–Turonian deposits of Western Siberia (age about 91.5 ± 8.5 Mya), and the results of the Feulgen test for the preservation of their structures' paleo-DNA in the nuclei. The study revealed the presence of fragments of embryo, megagametophyte and nucellus in the seed. The presence of megaspore membrane was also identified in the seed. The seed coat is 2–3-layered, the upper layer is very thin and presents just partially, and the middle layer of testa is represented by sclerotesta, the lower layer cells are fused into a single mass. It was established that nuclei are present in the cells of the embryo, megagametophyte and nucellus, however, in most cases, the DNA-deoxyribose skeleton, serving as a target for the Schiff reagent during the Feulgen reaction, is not cytologically detected in the nuclear chromatin. Only in two cases: in fragments of presumably embryonic tissue and megagametophyte, nuclei with a positive reaction according to Felgen were found, which indicates the preservation of aldehyde groups of deoxyribose in the nuclei of its individual parts.
{"title":"Seeds Alapaja (Cupressaceae) from the Cretaceous of Western Siberia and their paleo-DNA","authors":"A.A. Torshilova, I.A. Ozerov, N.A. Zhinkina, A.V. Rodionov","doi":"10.1016/j.revpalbo.2024.105236","DOIUrl":"10.1016/j.revpalbo.2024.105236","url":null,"abstract":"<div><div>The article presents the results of cytoembryological research of the structure of fossil seeds in coniferous plants <em>Alapaja</em> cf. <em>uralensis</em> (Cupressaceae) from the Cenomanian–Turonian deposits of Western Siberia (age about 91.5 ± 8.5 Mya), and the results of the Feulgen test for the preservation of their structures' paleo-DNA in the nuclei. The study revealed the presence of fragments of embryo, megagametophyte and nucellus in the seed. The presence of megaspore membrane was also identified in the seed. The seed coat is 2–3-layered, the upper layer is very thin and presents just partially, and the middle layer of testa is represented by sclerotesta, the lower layer cells are fused into a single mass. It was established that nuclei are present in the cells of the embryo, megagametophyte and nucellus, however, in most cases, the DNA-deoxyribose skeleton, serving as a target for the Schiff reagent during the Feulgen reaction, is not cytologically detected in the nuclear chromatin. Only in two cases: in fragments of presumably embryonic tissue and megagametophyte, nuclei with a positive reaction according to Felgen were found, which indicates the preservation of aldehyde groups of deoxyribose in the nuclei of its individual parts.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"332 ","pages":"Article 105236"},"PeriodicalIF":1.7,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-10DOI: 10.1016/j.revpalbo.2024.105235
Ranita Biswas , Manjuree Karmakar , Madhab Naskar , Oindrila Biswas , K. Althaf Ahamed Kabeer , Subir Bera
Grass Silica Short Cell Phytoliths (GSSCPs) are regarded as a potential adjunctive tool for grass subfamily identification owing to their definite morphology and affinity towards certain grass subfamilies. In the present study phytolith spectra of the monotypic genus Danthonidium gammiei (Bhide) Hubb. in Hook., collected from northern Western Ghats, Maharashtra is studied in detail for the first time. This grass profusely produces Bilobates along with other GSSCPs and Elongate types. A thorough study is undertaken to find out potential of the Danthonidium gammiei Bilobates in distinguishing this grass from other major Bilobate producing grass sub-families like Panicoideae and Aristidoideae. The possible relationship between Bilobates specific for Danthonidium gammiei and the intensity of rainfall in northern Western Ghats is also discussed here. Statistical analyses (PCA, CA, and CCA) also establish the potential of Bilobate phytoliths in identifying Danthonioideae subfamily and discriminating different rainfall zones of the region.
{"title":"Phytolith spectra of the monotypic grass Danthonidium gammiei (Bhide) Hubb. in Hook. (Danthonioideae) from Northern Western Ghats, India: Taxonomic and environmental significance of its distinctive Bilobates","authors":"Ranita Biswas , Manjuree Karmakar , Madhab Naskar , Oindrila Biswas , K. Althaf Ahamed Kabeer , Subir Bera","doi":"10.1016/j.revpalbo.2024.105235","DOIUrl":"10.1016/j.revpalbo.2024.105235","url":null,"abstract":"<div><div>Grass Silica Short Cell Phytoliths (GSSCPs) are regarded as a potential adjunctive tool for grass subfamily identification owing to their definite morphology and affinity towards certain grass subfamilies. In the present study phytolith spectra of the monotypic genus <em>Danthonidium gammiei</em> (Bhide) Hubb. in Hook., collected from northern Western Ghats, Maharashtra is studied in detail for the first time. This grass profusely produces B<span>ilobates</span> along with other GSSCPs and E<span>longate</span> types. A thorough study is undertaken to find out potential of the <em>Danthonidium gammiei</em> B<span>ilobates</span> in distinguishing this grass from other major B<span>ilobate</span> producing grass sub-families like Panicoideae and Aristidoideae. The possible relationship between B<span>ilobates</span> specific for <em>Danthonidium gammiei</em> and the intensity of rainfall in northern Western Ghats is also discussed here. Statistical analyses (PCA, CA, and CCA) also establish the potential of B<span>ilobate</span> phytoliths in identifying Danthonioideae subfamily and discriminating different rainfall zones of the region.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"332 ","pages":"Article 105235"},"PeriodicalIF":1.7,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-05DOI: 10.1016/j.revpalbo.2024.105233
Alina I. Iakovleva
The present paper augments the multidisciplinary stratigraphic analysis of the Global Stratotype Section and Point (GSSP) Bartonian-Priabonian boundary Alano di Piave section (NE Italy). Twenty-seven stratigraphically signficant organic walled dinoflagellate cyst events, calibrated against the magnetostratigraphic polarity timescale, and earlier established zonations based on calcareous microfossils are recognized. Among these events the first occurrence (FO) of Oligokolpoma agniniae sp. nov. (∼ 8 m below the GSSP boundary), and the FO of Reticulatosphaera actinocoronata (∼ 8 m above the GSSP boundary) may be considered as additional stratigraphic indicators for the Bartonian-Priabonian boundary. Six new potentially stratigraphically significant species Heteraulacacysta alanoensis sp. nov., Heteraulacacysta reticulata sp. nov., Impagidinium bellunoensis sp. nov., Impagidinium veneziaense sp. nov., Lophocysta domenicorioi sp. nov., and Oligokolpoma agniniae sp. nov. are formally described.
{"title":"Organic walled dinoflagellate cyst biostratigraphy of the Bartonian/Priabonian GSSP Alano di Piave section, NE Italy","authors":"Alina I. Iakovleva","doi":"10.1016/j.revpalbo.2024.105233","DOIUrl":"10.1016/j.revpalbo.2024.105233","url":null,"abstract":"<div><div>The present paper augments the multidisciplinary stratigraphic analysis of the Global Stratotype Section and Point (GSSP) Bartonian-Priabonian boundary Alano di Piave section (NE Italy). Twenty-seven stratigraphically signficant organic walled dinoflagellate cyst events, calibrated against the magnetostratigraphic polarity timescale, and earlier established zonations based on calcareous microfossils are recognized. Among these events the first occurrence (FO) of <em>Oligokolpoma agniniae</em> sp. nov. (∼<!--> <!-->8 m below the GSSP boundary), and the FO of <em>Reticulatosphaera actinocoronata</em> (∼<!--> <!-->8 m above the GSSP boundary) may be considered as additional stratigraphic indicators for the Bartonian-Priabonian boundary. Six new potentially stratigraphically significant species <em>Heteraulacacysta alanoensis</em> sp. nov., <em>Heteraulacacysta reticulata</em> sp. nov., <em>Impagidinium bellunoensis</em> sp. nov., <em>Impagidinium veneziaense</em> sp. nov., <em>Lophocysta domenicorioi</em> sp. nov., and <em>Oligokolpoma agniniae</em> sp. nov. are formally described.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"332 ","pages":"Article 105233"},"PeriodicalIF":1.7,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-28DOI: 10.1016/j.revpalbo.2024.105230
Yunkai Deng , Chunxia Zhang , Wenying Jiang , Yan Zhao , Zhengtang Guo
Comprehensive understanding of the modern pollen–vegetation relationship is crucial for utilizing fossil pollen to reconstruct palaeovegetation, especially in mountainous areas of southwestern China. In this study, we present forty-five modern surface samples collected from five different vegetation communities of the southern Gaoligong Mountains region, and the vegetation composition was investigated at each sample site. The modern pollen assemblages were analyzed through multivariate analysis to evaluate the relationships between vegetation types and pollen assemblages, and to investigate the representation of major pollen types in different vegetation types. The results indicate that the surface pollen assemblages of different vegetation types reliably represent the modern vegetation. The median R-values of dominant pollen taxa in the Gaoligong Mountains region can be ordered as follows: Pinus > Alnus > Poaceae > evergreen Quercus. The over-representation of Pinus pollen, attributed to its high productivity and strong dispersal ability, makes it the dominant component of exotic pollen. Conversely, the under-representation of evergreen Quercus suggests that the presence of its pollen within a sample might indicate the growth of the local parent plant in the study area. The human activities in the region have a recognizable effect on the surface pollen spectra and also exert a significant negative impact on pollen diversity. Our study supplements the modern pollen database of the mountain regions in southwestern China, and provides representative modern pollen analogues to interpret fossil pollen records from southwestern China and similar regions.
全面了解现代花粉与植被的关系对于利用花粉化石重建古植被至关重要，尤其是在中国西南山区。本研究从高黎贡山南部地区的五个不同植被群落中采集了 45 个现代地表样本，并对每个样本点的植被组成进行了调查。通过多元分析对现代花粉组合进行了分析，评估了植被类型与花粉组合之间的关系，并研究了主要花粉类型在不同植被类型中的代表性。结果表明，不同植被类型的地表花粉组合可靠地代表了现代植被。高黎贡山地区主要花粉类群的 R 值中位数排序如下松科（Pinus >）、桤木科（Alnus >）、禾本科（Poaceae >）、常绿柞树科（Quercus）。由于松科花粉产量高、传播能力强，因此在外来花粉中占主导地位。相反，常绿柞树花粉所占比例较低，这表明样本中出现常绿柞树花粉可能表明研究地区当地母本植物的生长情况。该地区的人类活动对地表花粉光谱有明显的影响，也对花粉多样性产生了显著的负面影响。我们的研究补充了中国西南山区的现代花粉数据库，为解释中国西南及类似地区的花粉化石记录提供了具有代表性的现代花粉类比。
{"title":"Relationships between pollen assemblages and modern vegetation of the southern Gaoligong Mountains region, southwest China","authors":"Yunkai Deng , Chunxia Zhang , Wenying Jiang , Yan Zhao , Zhengtang Guo","doi":"10.1016/j.revpalbo.2024.105230","DOIUrl":"10.1016/j.revpalbo.2024.105230","url":null,"abstract":"<div><div>Comprehensive understanding of the modern pollen–vegetation relationship is crucial for utilizing fossil pollen to reconstruct palaeovegetation, especially in mountainous areas of southwestern China. In this study, we present forty-five modern surface samples collected from five different vegetation communities of the southern Gaoligong Mountains region, and the vegetation composition was investigated at each sample site. The modern pollen assemblages were analyzed through multivariate analysis to evaluate the relationships between vegetation types and pollen assemblages, and to investigate the representation of major pollen types in different vegetation types. The results indicate that the surface pollen assemblages of different vegetation types reliably represent the modern vegetation. The median <em>R</em>-values of dominant pollen taxa in the Gaoligong Mountains region can be ordered as follows: <em>Pinus</em> > <em>Alnus</em> > Poaceae > evergreen <em>Quercus</em>. The over-representation of <em>Pinus</em> pollen, attributed to its high productivity and strong dispersal ability, makes it the dominant component of exotic pollen. Conversely, the under-representation of evergreen <em>Quercus</em> suggests that the presence of its pollen within a sample might indicate the growth of the local parent plant in the study area. The human activities in the region have a recognizable effect on the surface pollen spectra and also exert a significant negative impact on pollen diversity. Our study supplements the modern pollen database of the mountain regions in southwestern China, and provides representative modern pollen analogues to interpret fossil pollen records from southwestern China and similar regions.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"332 ","pages":"Article 105230"},"PeriodicalIF":1.7,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142560677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-28DOI: 10.1016/j.revpalbo.2024.105231
Wenjun Sun , Weiming Zhou , Yifei Wu , Josef Pšenička , Jason Hilton , Jun Wang
A marattialean fern with organically connected fertile and vegetative parts is described from the early Permian Wuda Tuff Flora in Inner Mongolia, China. The tripinnate fronds have typical pecopterid vegetative pinnules but do not match any known Pecopteris species. The fertile pinnules are distinctly different from the vegetative ones, with an extended margin that forms long lobes, bending abaxially to cover the synangia. Each fertile pinnule bears 7–10 ovate, pedicellate synangia arranged abaxially in a single row to either side of the midvein, with each synangium composed of 3–4 elongate sporangia. The sporangium wall is three-layered, with the outermost layer differentiated into four areas peripherally to provide differing mechanical strengths and facilitate dehiscence. In situ spores are trilete and 39–45 μm in diameter. These combined characteristics place the studied fern in the Scolecopteris Minor group of the Psaroniaceae family. The new species, Scolecopteris oxydonta sp. nov., exhibits many evolutionarily advanced traits such as modified fertile pinnules, unvascularized pedicels, differentiated sporangium walls, and a specialized opening mechanism. However, S. oxydonta sp. nov. also retains evolutionarily primitive traits including relatively large spores. S. oxydonta sp. nov. represents the fourth Scolecopteris species recognized from the Wuda Tuff Flora, adding to the growing body of evidence on the morphology and diversity of marattialean plants from the Permian of Cathaysia. We also consider preservational differences among the specimens and suggest that the composition and morphology of fertile pinnules produced closed microenvironments during early diagenesis that facilitated localized anatomical preservation.
{"title":"Scolecopteris oxydonta sp. nov., a new marattialean fern from the early Permian Wuda Tuff Flora","authors":"Wenjun Sun , Weiming Zhou , Yifei Wu , Josef Pšenička , Jason Hilton , Jun Wang","doi":"10.1016/j.revpalbo.2024.105231","DOIUrl":"10.1016/j.revpalbo.2024.105231","url":null,"abstract":"<div><div>A marattialean fern with organically connected fertile and vegetative parts is described from the early Permian Wuda Tuff Flora in Inner Mongolia, China. The tripinnate fronds have typical pecopterid vegetative pinnules but do not match any known <em>Pecopteris</em> species. The fertile pinnules are distinctly different from the vegetative ones, with an extended margin that forms long lobes, bending abaxially to cover the synangia. Each fertile pinnule bears 7–10 ovate, pedicellate synangia arranged abaxially in a single row to either side of the midvein, with each synangium composed of 3–4 elongate sporangia. The sporangium wall is three-layered, with the outermost layer differentiated into four areas peripherally to provide differing mechanical strengths and facilitate dehiscence. In situ spores are trilete and 39–45 μm in diameter. These combined characteristics place the studied fern in the <em>Scolecopteris</em> Minor group of the Psaroniaceae family. The new species, <em>Scolecopteris oxydonta</em> sp. nov., exhibits many evolutionarily advanced traits such as modified fertile pinnules, unvascularized pedicels, differentiated sporangium walls, and a specialized opening mechanism. However, <em>S. oxydonta</em> sp. nov. also retains evolutionarily primitive traits including relatively large spores. <em>S. oxydonta</em> sp. nov. represents the fourth <em>Scolecopteris</em> species recognized from the Wuda Tuff Flora, adding to the growing body of evidence on the morphology and diversity of marattialean plants from the Permian of Cathaysia. We also consider preservational differences among the specimens and suggest that the composition and morphology of fertile pinnules produced closed microenvironments during early diagenesis that facilitated localized anatomical preservation.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"332 ","pages":"Article 105231"},"PeriodicalIF":1.7,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142560676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-28DOI: 10.1016/j.revpalbo.2024.105232
Natalia Zavialova , Eugeny Karasev , Elke Schneebeli-Hermann , Wenben Li
Megaspores of Otynisporites eotriassicus, O. tuberculatus, and O. maculosus from the latest Changhsingian–early Induan of the Moscow Basin of Russia, O. eotriassicus from the Induan of the Kap Stosch subbasin of East Greenland, and O.? tarimensis, and Otynisporites? sp. from the Middle Triassic of the Tarim Basin of China were studied using light, scanning and transmission electron microscopy. The general morphology and sporoderm ultrastructure of all specimens prove their affinity with heterosporous lycopsids, but they are unexpectedly variable in details of the sculpture and ultrastructure. Megaspores of Otynisporites? sp. and O.? tarimensis differ significantly from the other studied megaspores and probably were produced by a different heterosporous lycopsid. Three morphological groups are distinguished within O. eotriassicus. Multilamellated zones are found only in O. tuberculatus and (much less distinct) in O. maculosus, that leads to the necessity to re-evaluate the phylogenetic value of this character. Analysis of morphology, stratigraphic and geographic ranges of earlier reports of Otynisporites shows that confirmed findings are confined to the latest Changhsingian–Induan, with O. tuberculatus and O. maculosus sharing the same stratigraphic range as O. eotriassicus. The geographic distribution shows that Otynisporites-producing plants grew under a moderately warm climate, in the middle latitudes. A comparison with the composition of palynological assemblages from megaspore-containing deposits implies that parent plants of O. eotriassicus, O. tuberculatus, and O. maculosus more probably produced trilete cavate microspores, Lundbladispora might be a counterpart for O. eotriassicus, whereas parent plants of O.? tarimensis and Otynisporites? sp. more probably produced monolete microspores.
采用光镜、扫描显微镜和透射电子显微镜研究了俄罗斯莫斯科盆地最晚长兴世-早期印支期的Otynisporites eotriassicus、O. tuberculatus和O. maculosus，东格陵兰卡普斯托什子盆地印支期的O. eotriassicus，以及中国塔里木盆地中三叠世的O. tarimensis和Otynisporites sp.所有标本的总体形态和孢子体超微结构都证明了它们与异孢茄科动物的亲缘关系，但它们在雕刻和超微结构细节上的差异出乎意料。Otynisporites sp.和 O. tarimensis 的巨孢子与其他研究的巨孢子有很大不同，可能是由不同的异孢番茄科植物产生的。在 O. eotriassicus 中可区分出三个形态组。只有在 O. tuberculatus 和 O. maculosus 中发现了多细胞区（不太明显），因此有必要重新评估这一特征的系统发育价值。对早期报告的 Otynisporites 的形态、地层和地理分布范围的分析表明，已确认的发现仅限于长兴期-印端期，O. tuberculatus 和 O. maculosus 与 O. eotriassicus 属于同一地层范围。地理分布表明，产生 Otynisporites 的植物生长在气候适中温暖的中纬度地区。与含巨型孢子的沉积物中的古植物组合成分进行比较后发现，O. eotriassicus、O. tuberculatus 和 O. maculosus 的母本植物更有可能产生三lete腔状小孢子，Lundbladispora 可能是 O. eotriassicus 的对应物，而 O. tarimensis 和 Otynisporites 的母本植物更有可能产生单lete小孢子。
{"title":"Permian/Triassic megaspores of Otynisporites (Fuglewicz) Karasev et Turnau, 2015: Diversity, botanical affinity, and stratigraphic significance","authors":"Natalia Zavialova , Eugeny Karasev , Elke Schneebeli-Hermann , Wenben Li","doi":"10.1016/j.revpalbo.2024.105232","DOIUrl":"10.1016/j.revpalbo.2024.105232","url":null,"abstract":"<div><div>Megaspores of <em>Otynisporites eotriassicus</em>, <em>O. tuberculatus</em>, and <em>O. maculosus</em> from the latest Changhsingian–early Induan of the Moscow Basin of Russia, <em>O. eotriassicus</em> from the Induan of the Kap Stosch subbasin of East Greenland, and <em>O.</em>? <em>tarimensis</em>, and <em>Otynisporites</em>? sp. from the Middle Triassic of the Tarim Basin of China were studied using light, scanning and transmission electron microscopy. The general morphology and sporoderm ultrastructure of all specimens prove their affinity with heterosporous lycopsids, but they are unexpectedly variable in details of the sculpture and ultrastructure. Megaspores of <em>Otynisporites</em>? sp. and <em>O.</em>? <em>tarimensis</em> differ significantly from the other studied megaspores and probably were produced by a different heterosporous lycopsid. Three morphological groups are distinguished within <em>O. eotriassicus</em>. Multilamellated zones are found only in <em>O. tuberculatus</em> and (much less distinct) in <em>O. maculosus</em>, that leads to the necessity to re-evaluate the phylogenetic value of this character. Analysis of morphology, stratigraphic and geographic ranges of earlier reports of <em>Otynisporites</em> shows that confirmed findings are confined to the latest Changhsingian–Induan, with <em>O. tuberculatus</em> and <em>O. maculosus</em> sharing the same stratigraphic range as <em>O. eotriassicus.</em> The geographic distribution shows that <em>Otynisporites-</em>producing plants grew under a moderately warm climate, in the middle latitudes. A comparison with the composition of palynological assemblages from megaspore-containing deposits implies that parent plants of <em>O. eotriassicus, O. tuberculatus,</em> and <em>O. maculosus</em> more probably produced trilete cavate microspores, <em>Lundbladispora</em> might be a counterpart for <em>O. eotriassicus,</em> whereas parent plants of <em>O.</em>? <em>tarimensis</em> and <em>Otynisporites</em>? sp. more probably produced monolete microspores.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"333 ","pages":"Article 105232"},"PeriodicalIF":1.7,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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