Review of Palaeobotany and Palynology最新文献_第9页

A palynological investigation of the Early-Middle Devonian transition and associated Choteč Event in Northern Spain 西班牙北部早泥盆世-中泥盆世过渡及相关乔特奇事件的古植物学调查

IF 1.7 3区地球科学

Review of Palaeobotany and Palynology Pub Date : 2024-10-22 DOI: 10.1016/j.revpalbo.2024.105222

Gilda Lopes , Silvia Blanco-Ferrera , David P.G. Bond , Sarah E. Greene , Jason Hilton , John E.A. Marshall , Javier Sanz-López , Charles H. Wellman

{"title":"A palynological investigation of the Early-Middle Devonian transition and associated Choteč Event in Northern Spain","authors":"Gilda Lopes , Silvia Blanco-Ferrera , David P.G. Bond , Sarah E. Greene , Jason Hilton , John E.A. Marshall , Javier Sanz-López , Charles H. Wellman","doi":"10.1016/j.revpalbo.2024.105222","DOIUrl":"10.1016/j.revpalbo.2024.105222","url":null,"abstract":"<div><div>In Northern Spain there is a near complete sequence of Devonian rocks that accumulated around a relatively isolated land mass, the Armorican Terrane Assemblage, which was separated from Gondwana to the south and Laurussia to the north. The Lower to Middle Devonian transition records a dramatic facies change from carbonate to siliciclastic sedimentation. The Choteč Event, a global anoxic pulse that occurs just above the Lower-Middle Devonian boundary (392.5–393.1 Ma), has been identified within this transition. These strata are included in the Moniello and Naranco fms in Asturias and the equivalent Santa Lucía and Huergas fms in Leon. They are independently age-contrained based on conodont and invertebrate biotas. For the first time we describe palynomorph assemblages recovered from the Lower to Middle Devonian transition in Northern Spain. The assemblages contain terrestrial (spores) and marine (acritarchs, prasinophycean cysts, chitinozoans) elements, thus recording primary productivity on both the land and in the oceans. The older assemblages belong to the <em>annulatus–sextantii</em> Spore Zone and the younger assemblages the <em>douglastownensis–eurypterota</em> Spore Zone, which is concordant with the independent age constraints. Our analysis of the distribution and diversity of marine and terrestrial palynomorphs supports interpretations of the facies change associated with the Choteč Event as being related to a change to increased rainfall and terrestrial runoff. However, this change is associated with only limited taxon turnover in both land plant spores and marine phytoplankton and chitinozoans.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"332 ","pages":"Article 105222"},"PeriodicalIF":1.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553842","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}

引用次数: 0

Phytolith characterization of culturally salient plant species of the Pacific Northwest of North America 北美西北太平洋地区具有文化价值的植物物种的植化石特征描述

IF 1.7 3区地球科学

Review of Palaeobotany and Palynology Pub Date : 2024-10-18 DOI: 10.1016/j.revpalbo.2024.105220

Levi Cormier, Chelsey Geralda Armstrong

{"title":"Phytolith characterization of culturally salient plant species of the Pacific Northwest of North America","authors":"Levi Cormier, Chelsey Geralda Armstrong","doi":"10.1016/j.revpalbo.2024.105220","DOIUrl":"10.1016/j.revpalbo.2024.105220","url":null,"abstract":"<div><div>Palaeoecological and archaeological studies often use soil phytoliths to gain insight into past vegetation changes and the long-term use of plants by people, particularly domesticated cultivars. However, to make accurate interpretations and analyses using plant phytoliths, regionally-specific reference collections are warranted. There is ample research documenting phytolith morphotypes observed in grass species worldwide (due to their high phytolith production), and of dicots in tropical regions, but there is dearth of phytolith references for dicot species in temperate regions like the Pacific Northwest of North America. This study aims to fill part of this gap by documenting phytolith morphotypes observed in 60 culturally important plant foods, medicines, and textiles, all predominantly dicot species. Phytoliths are classified by abundance in specific plant parts (e.g., stem, leaf, flower) and the findings are compared to closely related species studied elsewhere. Results indicate that many of the dicot plant species in the Pacific Northwest produce more phytoliths than closely related species worldwide, likely due to differing environmental factors which affect phytolith production in plants. These findings could be useful in palaeoecological contexts to assess vegetation changes or identify dicot-dominated ecosystems, like Indigenous cultivated and managed forests and other perennial fruit tree/shrub dominated landscapes. Additionally, three of the species studied here showed possible diagnostic phytoliths but further confirmation is warranted. Future studies should consider localized environmental patterns affecting phytolith production, and therefore, our understanding of phytolith taxonomy and deposition/taphonomy.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"332 ","pages":"Article 105220"},"PeriodicalIF":1.7,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537203","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}

引用次数: 0

A marattialean fern with in situ spores, Cyathocarpus benefoliatii sp. nov., from the Lopingian of Southwest China 中国西南罗平滇地区发现的一种具有原位孢子的蕨类植物--Cyathocarpus benefoliatii sp.

IF 1.7 3区地球科学

Review of Palaeobotany and Palynology Pub Date : 2024-10-16 DOI: 10.1016/j.revpalbo.2024.105218

Yun Guo , Yu Zhou , Josef Pšenička , Jiří Bek , Zhuo Feng

{"title":"A marattialean fern with in situ spores, Cyathocarpus benefoliatii sp. nov., from the Lopingian of Southwest China","authors":"Yun Guo , Yu Zhou , Josef Pšenička , Jiří Bek , Zhuo Feng","doi":"10.1016/j.revpalbo.2024.105218","DOIUrl":"10.1016/j.revpalbo.2024.105218","url":null,"abstract":"<div><div>A species of adpressed marattialean fern having pinnules with fertile organs, <em>Cyathocarpus benefoliatii</em> Yu.Guo, Zhou et Z.Feng sp. nov., is established from the Lopingian (upper Permian) of eastern Yunnan Province, Southwest China. Fronds of this new species are at least tripinnate, with alternately arranged penultimate pinnae, alternately or suboppositely arranged ultimate pinnae, and alternately arranged pinnules. Fertile pinnules are linguiform in shape and abaxially bear a row of 4–7 synangia tightly arranged on each side of the midvein from the base to the apex. Synangia are ovoidal, radially symmetrical, and individually consists of 4 or 5 exannulate sporangia. Sporangia are ovoidal and laterally fused along most or all of their length. The inner-facing sporangial wall has one layer of cells, while the outer-facing sporangial wall has three layers of cells. In situ spores of the <em>Laevigatosporites</em>/<em>Latosporites</em> type are 43–61 μm in diameter, monolete, and laevigate. The exine encompasses a perine, a sexine, and a nexine. These characteristics indicate that <em>Cyathocarpus benefoliatii</em> sp. nov. belongs to the <em>Pecopteris trevirani</em> Group (palynological grouping) of Paleozoic marattialeans.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"331 ","pages":"Article 105218"},"PeriodicalIF":1.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530313","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}

引用次数: 0

Re-investigation of Bowmanites laxus Halle, 1927, a sphenopsid fructification from the Permian of China 重新研究中国二叠纪的一种蝶形花Bowmanites laxus Halle, 1927

IF 1.7 3区地球科学

Review of Palaeobotany and Palynology Pub Date : 2024-10-09 DOI: 10.1016/j.revpalbo.2024.105214

Jian Yang , Francis M. Hueber , Yue-Zhuo Li , Cheng-Sen Li

{"title":"Re-investigation of Bowmanites laxus Halle, 1927, a sphenopsid fructification from the Permian of China","authors":"Jian Yang , Francis M. Hueber , Yue-Zhuo Li , Cheng-Sen Li","doi":"10.1016/j.revpalbo.2024.105214","DOIUrl":"10.1016/j.revpalbo.2024.105214","url":null,"abstract":"<div><div>Halle (1927) described and illustrated sphenopsid plant remains from Permian strata (Shihottse Formation) in Shanxi Province, China in the early 1920s. He designated the particular stratigraphic sources as Plant Bearing Beds 14 and 31 and described <em>Bowmanites laxus,</em> n. sp. from the former and <em>Bowmanites</em> sp. from the latter. The illustrated specimens, as well as additional ones from both beds were borrowed from the Palaeobotanical Collections of the Swedish Museum of Natural History, Stockholm, Sweden and re-investigated in order to prepare, re-illustrate, describe, and compare the species. The preparations revealed that the leaves in both species have the same morphology in the strobili as well as in the sterile axes and are arranged in open, not laterally fused whorls. Each leaf is arcuate and upwardly turned, the lamina is narrow at the point of attachment，and gradually expanded to become bilaterally laciniate and medially elongated into a sharply pointed apex. The sporangiophore in both species is axillary to the subtending sporophyll, remains free, following the upward curve of the sporophyll, and terminally, bears two peltately suspended sporangia that are aligned parallel to the lamina of the sporophyll. A single lectotype is chosen from/among the lectotype suite previously defined by Hoskins and Cross (1943). A systematic classification of the species is proposed. The summary of revisions of other sphenopsid species as suggested by Hoskins and Cross (1943) is presented in relationship to their proposal to divide the species of <em>Bowmanites</em> into three Sections in one of which <em>B. laxus</em> is included.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"331 ","pages":"Article 105214"},"PeriodicalIF":1.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442185","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}

引用次数: 0

Archaeopteris trees at high southern latitudes in the late Devonian 泥盆纪晚期南方高纬度地区的古蝶形花树

IF 1.7 3区地球科学

Review of Palaeobotany and Palynology Pub Date : 2024-10-09 DOI: 10.1016/j.revpalbo.2024.105212

Robert W. Gess , Christopher Berry

{"title":"Archaeopteris trees at high southern latitudes in the late Devonian","authors":"Robert W. Gess , Christopher Berry","doi":"10.1016/j.revpalbo.2024.105212","DOIUrl":"10.1016/j.revpalbo.2024.105212","url":null,"abstract":"<div><div>During the Devonian Period plants first reached forest stature, impacting chemical weathering of rocks, fluvial systems, atmospheric composition and possibly aquatic eutrophication. Hypothetically these factors contributed to increasing climatic instability culminating in the End Devonian Mass Extinction Event. Understanding the timing of the spread of forests is however a prerequisite to correlation with its proposed consequences. Though evidence for forests at low palaeolatitudes demonstrates their emergence by the mid Devonian, sparse high-palaeolatitude records almost entirely comprise herbaceous lycopods. By the Famennian forest ecosystems are widely evidenced at low palaeolatitudes, however high latitude palaeofloras are almost exclusively represented by a single locality, the Waterloo Farm lagerstätte from South Africa (approximate palaeolatitude, 70°S). Understanding climatic and ecological conditions at this locality is doubly important as it also hosts diverse vertebrate taxa, including the only high latitude Devonian tetrapods. <em>Archaeopteris</em>, the quintessential Late Devonian woody tree, has previously been identified at this locality on the basis of leafy branch system fragments, though some uncertainty has remained as to whether these represent tree sized organisms. Here we present co-occurring large axes, including a trunk base, attributable to <em>Archaeopteris</em> trees inferred to be in excess of 20 m height, the first demonstration of forest stature at high latitudes in the Devonian. This possibly reflects high latitude climatic amelioration, resultant from warm ocean currents circulating southwards in response to progressive closure of the Iapetus Sea. As such, changing continental configurations may have indirectly facilitated the spread of forest ecosystems and helped to drive climatic instability and ultimately extinctions towards the end of the Devonian.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"331 ","pages":"Article 105212"},"PeriodicalIF":1.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434183","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}

引用次数: 0

Vegetation and environmental changes on the Northeast China Plain during warm periods since MIS 3 自 MIS 3 以来温暖时期中国东北平原的植被和环境变化

IF 1.7 3区地球科学

Review of Palaeobotany and Palynology Pub Date : 2024-10-09 DOI: 10.1016/j.revpalbo.2024.105217

Liming Xu , Zhipeng Li , Pai Yue , Weijie Tang , Yiren Liu , Wei Chen , Min Xu , Jinglian Ge

{"title":"Vegetation and environmental changes on the Northeast China Plain during warm periods since MIS 3","authors":"Liming Xu , Zhipeng Li , Pai Yue , Weijie Tang , Yiren Liu , Wei Chen , Min Xu , Jinglian Ge","doi":"10.1016/j.revpalbo.2024.105217","DOIUrl":"10.1016/j.revpalbo.2024.105217","url":null,"abstract":"<div><div>Understanding past terrestrial ecosystem responses to climate changes is vital for future predictions, but research in densely populated plains is limited due to insufficient materials. This study focuses on vegetation and environmental changes in the Northeast China Plain since Marine Isotopic Stage (MIS) 3 using pollen analysis from core WCZK03. The findings reveal significant shifts in vegetation that correspond to climatic events. During MIS 3 (52–29 cal ka BP), the region was predominantly a lake environment with vegetation transitioning from grassland dominated by Poaceae, Chenopodiaceae and <em>Artemisia</em> to conifer-broadleaf mixed forests as the climate ameliorated. The Last Glacial Maximum (29–17 cal ka BP) was characterized by loess deposits, followed by drought-tolerant grassland (17.0–11.3 cal ka BP) dominated by <em>Artemisia</em> and Chenopodiaceae in the plain. The onset of the Holocene witnessed the expansion of conifer and broad-leaved deciduous forests in hilly areas and the retreat of grassland in the plain. The sedimentary sequence shows transitions from fluvial-lacustrine deposits to loess-like and black soil deposits, showing significant environmental changes. This study suggests that changes in vegetation on the Northeast China Plain were closely related to regional climate patterns and were more responsive to climate changes than the surrounding mountainous areas.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"331 ","pages":"Article 105217"},"PeriodicalIF":1.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434182","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}

引用次数: 0

Calophyllum L.: An important tropical element in the monsoon-influenced ancient Siwalik Forest of eastern Himalaya Calophyllum L.：喜马拉雅东部受季风影响的古老西瓦利克森林中的重要热带元素

IF 1.7 3区地球科学

Review of Palaeobotany and Palynology Pub Date : 2024-10-09 DOI: 10.1016/j.revpalbo.2024.105215

Sumana Mahato , Sandip More , Suchana Taral , Tapan Chakrabarty , Mahasin Ali Khan

{"title":"Calophyllum L.: An important tropical element in the monsoon-influenced ancient Siwalik Forest of eastern Himalaya","authors":"Sumana Mahato , Sandip More , Suchana Taral , Tapan Chakrabarty , Mahasin Ali Khan","doi":"10.1016/j.revpalbo.2024.105215","DOIUrl":"10.1016/j.revpalbo.2024.105215","url":null,"abstract":"<div><div><em>Calophyllum</em> vegetative (leaves and woods) fossil remains have been widely reported from the Cenozoic sedimentary strata across the Northern and Southern Hemispheres. However, until now, no reproductive megafossil remains have been discovered. Here, we report and describe <em>Calophyllum</em> fossil fruits from the Siwalik (middle Miocene–Pliocene) sediments of Darjeeling foothills, eastern Himalaya for the first time. In addition, we also provide fossil materials of isolated leaves in appreciable numbers recovered from the same stratigraphic level. Our Siwalik fossils and extant members of <em>Calophyllum</em> are closely related morphologically by stalked, ball-shaped (spherical to ovoid) drupe with a thin, dark brown, smooth surfaced outer layer and a hard endocarp; and symmetrical, oblong-elliptic shaped entire margined lamina with numerous close parallel secondary veins, and obscure tertiary veins. Based upon morphology and epidermal anatomy, the fossil fruits are recognized as a new fossil-species <em>Calophyllum ramthiene</em> sp. nov. The present <em>Calophyllum</em> leaf and fruit fossils, along with previous reports suggest that <em>Calophyllum</em> was an important forest element throughout the eastern Himalaya during the period of Siwalik sedimentation (Mio-Pleistocene time). We briefly discuss the fossil history of <em>Calophyllum</em> and palaeobiogeography in India and palaeoclimatic implications regarding the distribution and habitat of fossil and modern members of <em>Calophyllum</em>.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"331 ","pages":"Article 105215"},"PeriodicalIF":1.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530311","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}

引用次数: 0

The middle Miocene Hamjin flora and preliminary palaeoclimatic analysis of the Democratic People's Republic of Korea 朝鲜民主主义人民共和国中新世咸津植物区系和初步古气候分析

IF 1.7 3区地球科学

Review of Palaeobotany and Palynology Pub Date : 2024-10-09 DOI: 10.1016/j.revpalbo.2024.105216

Myong-Sim Kim, Jong-Jun Ko, Kwang-Il An, Hyon-Jong Kim, Yong-Sik Jong, Song-Chol Hong

引用次数: 0

Nectar and pollen source of natural honey produced by Apis cerana skorikovi Engel (= himalaya): Palynological analysis from tropical to sub-tropical forests of eastern Himalaya 恩格尔蜂（Apis cerana skorikovi Engel）（=himalaya）所产天然蜂蜜的花蜜和花粉来源：喜马拉雅东部热带至亚热带森林的古生物学分析

IF 1.7 3区地球科学

Review of Palaeobotany and Palynology Pub Date : 2024-10-05 DOI: 10.1016/j.revpalbo.2024.105210

Shreyasi Basak , Oindrila Biswas , Bijoy Chhetri , Sonali Rai , Dipak Kumar Paruya , Dulal Chandra Patra , Subir Bera

{"title":"Nectar and pollen source of natural honey produced by Apis cerana skorikovi Engel (= himalaya): Palynological analysis from tropical to sub-tropical forests of eastern Himalaya","authors":"Shreyasi Basak , Oindrila Biswas , Bijoy Chhetri , Sonali Rai , Dipak Kumar Paruya , Dulal Chandra Patra , Subir Bera","doi":"10.1016/j.revpalbo.2024.105210","DOIUrl":"10.1016/j.revpalbo.2024.105210","url":null,"abstract":"<div><div>This study deals with the palynological analysis of natural “Himalayan <em>cerana</em>” honey collected from the tropical to sub-tropical forests of the eastern Himalaya (West Sikkim, Ziro valley of Arunachal Pradesh and sub-Himalayan region of West Bengal). A total of 12 honey samples were analysed. Among the six samples from Sikkim, one is found unifloral and remaining five samples are found to be multifloral. Similarly, the Kolakham (West Bengal) sample is found multifloral, whereas both the honey samples of Alipurduar (West Bengal) are found to be unifloral. All the three Arunachal Pradesh samples are found multifloral. Absolute pollen count (APC) reveals that the unifloral winter honeys are poor in APC compared to the multifloral ones. Significant occurrence of anemophilous pollen grains in honey samples points towards theirr entrapment either during long distance flight of the bees or on the sticky hive surfaces. The nectar calendars show that winter season is the honey dearth period in the study areas of the eastern Himalaya. Finally, the diversity and richness of the pollen grains in the honey samples also reflect the bee plant diversity of the surroundings. The study may further be useful to assess the potentiality for establishing a moderate to large-scale bee-keeping industry which may provide an alternate source of livelihood to improve the socio-economic set up of the local economically backward ethnic communities.</div></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"332 ","pages":"Article 105210"},"PeriodicalIF":1.7,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537202","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}

引用次数: 0

The last millennium vegetation and environmental history of the Hyrcanian highland region, a pollen record from Shekardasht mire, northern Iran 伊朗北部谢卡达什特泥沼的花粉记录：希尔卡尼亚高原地区上千年的植被和环境历史

IF 1.7 3区地球科学

Review of Palaeobotany and Palynology Pub Date : 2024-10-05 DOI: 10.1016/j.revpalbo.2024.105213

Faezeh Nourmohammad , Elias Ramezani , Hermann Behling

引用次数: 0