Ten palm leaf impressions are documented from the latest Maastrichtian(late Cretaceous) to early Danian(earliest Paleocene) sediments(K-Pg,c.66-64 Ma) of the Mandla Lobe of the Deccan Intertrappean Beds,Madhya Pradesh...Ten palm leaf impressions are documented from the latest Maastrichtian(late Cretaceous) to early Danian(earliest Paleocene) sediments(K-Pg,c.66-64 Ma) of the Mandla Lobe of the Deccan Intertrappean Beds,Madhya Pradesh,central India.The palmate leaf shape along with a definite wellpreserved costa support their placement in the subfamily Coryphoideae of the family Arecaceae.We place all recovered palm leaf specimens in the fossil genus Sabalites,report seven species of coryphoid palms and describe two new species namely,Sabalities umariaensis sp.nov.and Sabalites ghughuaensis sp.nov.The fossils indicate that coryphoid palms were highly diverse in central India by the latest Cretaceous.These and earlier reported coryphoid palm fossils from the same locality indicate that they experienced a warm and humid tropical environment during the time of deposition.These discoveries confirm the presence of a diversity of Coryphoideae in Gondwana prior to the India-Eurasia collision and provide information about coryphoid biogeographical history over geological time.Based on megafossil remains,we trace coryphoid palm migration pathways from India to mainland Southeast(SE) Asia and other parts of Asia after the docking of the Indian subcontinent with Eurasia early in the Paleogene.展开更多
Equisetum(Equisetaceae)has long been a focus of attention for botanists and palaeontologists because,given its extensive and well-documented fossil record,it is considered the oldest extant vascular plant and a key el...Equisetum(Equisetaceae)has long been a focus of attention for botanists and palaeontologists because,given its extensive and well-documented fossil record,it is considered the oldest extant vascular plant and a key element in understanding vascular plant evolution.However,to date,no authentic fossil evidence of Equisetum has been found from the Indian Cenozoic.Here,we describe a new fossil species,namely,E.siwalikum sp.nov.,recovered from the middle Siwalik(Late Miocene)sediments of Himachal Pradesh,western Himalaya.We identified fossil specimens based on morphological and epidermal characters.In addition,X-Ray diffraction(XRD)analysis was used to determine the mineral composition of compressed stems of Equisetum.The close affinity of our recovered Siwalik fossils to Equisetum is supported by the presence of both macromorphological and epidermal characters.Because Equisetum generally grows in wet conditions around water reservoirs,our findings indicate that the fossil locality was humid and surrounded by swamp and lowland regions during deposition.Ample fossil evidence indicates that this sphenopsid once existed in the western Himalaya during the Siwalik period.However,at present Equisetum is confined to a particular area of our fossil locality,probably a consequence of severe environmental changes coupled with competition from opportunistic angiosperms.Our discovery of Equisetum fossils in appreciable numbers from the Siwalik sediments of the Himachal Himalayas is unique and constitutes the first reliable recognition of Equisetum from the Indian Cenozoic.展开更多
A new Quercus （Fagaceae） morphospecies is described based on well-preserved fossil leaves.The fossils were collected from Yangyi Formation of the Upper Pliocene at the Yangyi coalmine,Baoshan,western Yunnan,China.De...A new Quercus （Fagaceae） morphospecies is described based on well-preserved fossil leaves.The fossils were collected from Yangyi Formation of the Upper Pliocene at the Yangyi coalmine,Baoshan,western Yunnan,China.Details of the microstructure of mesophyll tissue are preserved because lithification of the fossils was not complete.The fossil laminas possess typical characteristics of Quercus sect.Heterobalanus：quite thick and coriaceous cuticle; secondary veins bifurcating near the margin in the middle and top of the leaf; and upper epidermis with adaxial hypodermis.Based on a detailed morphological and anatomical comparison with all living and fossil species of Quercus sect.Heterobalanus,the fossil leaves prove to be different in their sparse and garland-shaped multicellular trichomes on the lower epidermis,and so it is described as a new species Quercus yangyiensis He,Li et Sun sp.nov.The much sparser trichomes of our fossils compare well with those of living Quercus sect.Heterobalanus and indicate a more humid climate during the deposition of the Yangyi Formation in the Late Pliocene.展开更多
Leaf cuticle analysis has long been a powerful tool for fossil plant identification,systematics,and palaeoclimatological recon-struction.In recent decades the application of stomatal frequency data that are relied on ...Leaf cuticle analysis has long been a powerful tool for fossil plant identification,systematics,and palaeoclimatological recon-struction.In recent decades the application of stomatal frequency data that are relied on precise calculation of stomata on plant fossil cuticles to reconstruct ancient atmospheric CO2 concentration made the preparation of cuticular membrane with suffi-cient size a critical technique in palaeoclimatological research.However,for plants with originally thin and fragile cuticles,e.g.,most deciduous plants,conventional techniques sometimes fail to obtain cuticular membranes with sufficient size,or sometimes unable to recover any.This has largely hampered the usage of fossil cuticle analysis in palaeobotanical and palaeoclimatological research.Here,we describe a new method using clear nail polish as a medium to "strengthen" the originally thin and fragile cuticles prior to maceration procedures.We demonstrate the method by using middle Eocene Metasequoia fossils that were notorious for the difficulty of recovering large-sized clean cuticular membranes due to their thin and fragile nature.Metasequoia,with well-documented and widely-distributed fossil records since the Late Cretaceous and with a living representative,M.glyptostroboides,as a comparative reference,has been widely used as a model genus for the study of evolution of plants,palaeoclimatological reconstruction,and plant adaptation to climate changes.But its deciduous habit produces thin cuticles and makes the preparation of clean cuticular membranes a tedious process.The new method successfully allows us to recover its delicate cuticular membranes with sufficient sizes for SEM observation and stomatal frequency analysis.展开更多
Fossil leaves resembling Nothofagaceae have been investigated from the Eocene of western Antarctica and a new form genus Nothofagofolia is proposed for these kinds of fossils. Some new specimens belonging to this form...Fossil leaves resembling Nothofagaceae have been investigated from the Eocene of western Antarctica and a new form genus Nothofagofolia is proposed for these kinds of fossils. Some new specimens belonging to this form genus are described. They were collected from the Fossil Hill locality of Fildes Peninsula, King George Island, South Shetland Islands, western Antarctica. Two new species, two new combinations and an unnamed species are reported. A number of published Nothofagus leaf fossils from the same locality are discussed and revised. As a result of these studies of Nothofagus leaf morphology, we conclude that (1) Nothofagus probably originated in high latitudes of the Southern Hemisphere during the middle-late Late Cretaceous and diversified, dispersed gradually to the lower latitudes of the same hemisphere; (2) leaf morphological characters are significant for the systematics of the family Nothofagaceae, especially at the intrageneric level; and (3) extant species of Nothofagus known from southern temperate areas have more primitive leaf morphological characters and lower leaf ranks than those from tropical mountains as well as those of the Fagaceae and Betulaceae.展开更多
树木生长轮记录了植物生长期的气候环境信息及其生理响应过程,而这些信息可以通过定量分析生长轮的解剖学特征获得,因此生长轮的定量分析被广泛应用于林学、地理学、古气候学和古生物学等研究领域。我国虽然保存了丰富的木化石,但前人...树木生长轮记录了植物生长期的气候环境信息及其生理响应过程,而这些信息可以通过定量分析生长轮的解剖学特征获得,因此生长轮的定量分析被广泛应用于林学、地理学、古气候学和古生物学等研究领域。我国虽然保存了丰富的木化石,但前人多从系统分类学角度研究木化石,而较少利用木化石生长轮定量分析方法开展古气候环境的研究。本文主要结合松柏类木化石生长轮定量研究的案例,对生长轮定量研究的主要方法和常用参数进行了系统比较和讨论,包括:生长轮宽度(Growth-ring Width)、年敏感度(Annual Sensitivity)、平均敏感度(Mean Sensitivity)、生长轮显著度指数(Ring Markedness Index)、晚材率(Percentage Latewood)、细胞减小率(Percentage Diminution)、脆弱性指数(Vulnerability Index)、中生形态指数(Mesomorphy Index)、生长轮类型的划分以及细胞直径与直径平均值差值的累计代数和(cumulative algebraic sum of each cell’s deviation from the mean of the radial diameters, CSDM)。生长轮定量研究的参数和方法在松柏类木化石中的应用,不仅有助于深入了解地质历史时期古气候环境信息,而且在树叶寿命推算方面也有重要应用潜力。因此,松柏类木化石生长轮的定量研究在揭示古气候、古环境和古物候学方面具有不可替代的独特优势。展开更多
基金Financial support from the Department of Science and Technology (DST),New Delhi (Ref.no.DST/INSPIRE/03/2019/001456)supported by an INSPIRE fellowship awarded to S.K.by The Department of Science and Technology,New Delhi,INSPIRE Code (IF190496) S.K.,T.H.,M.H.
文摘Ten palm leaf impressions are documented from the latest Maastrichtian(late Cretaceous) to early Danian(earliest Paleocene) sediments(K-Pg,c.66-64 Ma) of the Mandla Lobe of the Deccan Intertrappean Beds,Madhya Pradesh,central India.The palmate leaf shape along with a definite wellpreserved costa support their placement in the subfamily Coryphoideae of the family Arecaceae.We place all recovered palm leaf specimens in the fossil genus Sabalites,report seven species of coryphoid palms and describe two new species namely,Sabalities umariaensis sp.nov.and Sabalites ghughuaensis sp.nov.The fossils indicate that coryphoid palms were highly diverse in central India by the latest Cretaceous.These and earlier reported coryphoid palm fossils from the same locality indicate that they experienced a warm and humid tropical environment during the time of deposition.These discoveries confirm the presence of a diversity of Coryphoideae in Gondwana prior to the India-Eurasia collision and provide information about coryphoid biogeographical history over geological time.Based on megafossil remains,we trace coryphoid palm migration pathways from India to mainland Southeast(SE) Asia and other parts of Asia after the docking of the Indian subcontinent with Eurasia early in the Paleogene.
基金DST-SERB,GOI,New Delhi,India(File no.CRG/2020/001303)for their financial assistance。
文摘Equisetum(Equisetaceae)has long been a focus of attention for botanists and palaeontologists because,given its extensive and well-documented fossil record,it is considered the oldest extant vascular plant and a key element in understanding vascular plant evolution.However,to date,no authentic fossil evidence of Equisetum has been found from the Indian Cenozoic.Here,we describe a new fossil species,namely,E.siwalikum sp.nov.,recovered from the middle Siwalik(Late Miocene)sediments of Himachal Pradesh,western Himalaya.We identified fossil specimens based on morphological and epidermal characters.In addition,X-Ray diffraction(XRD)analysis was used to determine the mineral composition of compressed stems of Equisetum.The close affinity of our recovered Siwalik fossils to Equisetum is supported by the presence of both macromorphological and epidermal characters.Because Equisetum generally grows in wet conditions around water reservoirs,our findings indicate that the fossil locality was humid and surrounded by swamp and lowland regions during deposition.Ample fossil evidence indicates that this sphenopsid once existed in the western Himalaya during the Siwalik period.However,at present Equisetum is confined to a particular area of our fossil locality,probably a consequence of severe environmental changes coupled with competition from opportunistic angiosperms.Our discovery of Equisetum fossils in appreciable numbers from the Siwalik sediments of the Himachal Himalayas is unique and constitutes the first reliable recognition of Equisetum from the Indian Cenozoic.
基金financially supported by the National Basic Research Program of China(973 Program)(No.2012CB822003)the National Natural Science Foundation of China(No.41172022)Specialized Research Fund for the Doctoral Program of Higher Education(No.20120211110022)
文摘A new Quercus （Fagaceae） morphospecies is described based on well-preserved fossil leaves.The fossils were collected from Yangyi Formation of the Upper Pliocene at the Yangyi coalmine,Baoshan,western Yunnan,China.Details of the microstructure of mesophyll tissue are preserved because lithification of the fossils was not complete.The fossil laminas possess typical characteristics of Quercus sect.Heterobalanus：quite thick and coriaceous cuticle; secondary veins bifurcating near the margin in the middle and top of the leaf; and upper epidermis with adaxial hypodermis.Based on a detailed morphological and anatomical comparison with all living and fossil species of Quercus sect.Heterobalanus,the fossil leaves prove to be different in their sparse and garland-shaped multicellular trichomes on the lower epidermis,and so it is described as a new species Quercus yangyiensis He,Li et Sun sp.nov.The much sparser trichomes of our fossils compare well with those of living Quercus sect.Heterobalanus and indicate a more humid climate during the deposition of the Yangyi Formation in the Late Pliocene.
基金supported by CAS/SAFEA International Partnership Program for Creative Research Teams,the Pilot Project of Knowledge Innovation of CAS (Grant No. KZCX2-YW-105)National Basic Research Program of China (Grant No. 2006CB806400)National Natural Science Foundation of China (Grant Nos. 40402002,40872011)
文摘Leaf cuticle analysis has long been a powerful tool for fossil plant identification,systematics,and palaeoclimatological recon-struction.In recent decades the application of stomatal frequency data that are relied on precise calculation of stomata on plant fossil cuticles to reconstruct ancient atmospheric CO2 concentration made the preparation of cuticular membrane with suffi-cient size a critical technique in palaeoclimatological research.However,for plants with originally thin and fragile cuticles,e.g.,most deciduous plants,conventional techniques sometimes fail to obtain cuticular membranes with sufficient size,or sometimes unable to recover any.This has largely hampered the usage of fossil cuticle analysis in palaeobotanical and palaeoclimatological research.Here,we describe a new method using clear nail polish as a medium to "strengthen" the originally thin and fragile cuticles prior to maceration procedures.We demonstrate the method by using middle Eocene Metasequoia fossils that were notorious for the difficulty of recovering large-sized clean cuticular membranes due to their thin and fragile nature.Metasequoia,with well-documented and widely-distributed fossil records since the Late Cretaceous and with a living representative,M.glyptostroboides,as a comparative reference,has been widely used as a model genus for the study of evolution of plants,palaeoclimatological reconstruction,and plant adaptation to climate changes.But its deciduous habit produces thin cuticles and makes the preparation of clean cuticular membranes a tedious process.The new method successfully allows us to recover its delicate cuticular membranes with sufficient sizes for SEM observation and stomatal frequency analysis.
基金Foundation of State Key Laboratory of Palaeobiology & Stratigra-phy, Nanjing Institute of Geology and Palaoentology, Chinese Academy of Sciences (Grant No. 013106)the National Natural Science Foundation of China (Grant No. 30670159)the Fund of Innovation Program by Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences
文摘Fossil leaves resembling Nothofagaceae have been investigated from the Eocene of western Antarctica and a new form genus Nothofagofolia is proposed for these kinds of fossils. Some new specimens belonging to this form genus are described. They were collected from the Fossil Hill locality of Fildes Peninsula, King George Island, South Shetland Islands, western Antarctica. Two new species, two new combinations and an unnamed species are reported. A number of published Nothofagus leaf fossils from the same locality are discussed and revised. As a result of these studies of Nothofagus leaf morphology, we conclude that (1) Nothofagus probably originated in high latitudes of the Southern Hemisphere during the middle-late Late Cretaceous and diversified, dispersed gradually to the lower latitudes of the same hemisphere; (2) leaf morphological characters are significant for the systematics of the family Nothofagaceae, especially at the intrageneric level; and (3) extant species of Nothofagus known from southern temperate areas have more primitive leaf morphological characters and lower leaf ranks than those from tropical mountains as well as those of the Fagaceae and Betulaceae.
文摘树木生长轮记录了植物生长期的气候环境信息及其生理响应过程,而这些信息可以通过定量分析生长轮的解剖学特征获得,因此生长轮的定量分析被广泛应用于林学、地理学、古气候学和古生物学等研究领域。我国虽然保存了丰富的木化石,但前人多从系统分类学角度研究木化石,而较少利用木化石生长轮定量分析方法开展古气候环境的研究。本文主要结合松柏类木化石生长轮定量研究的案例,对生长轮定量研究的主要方法和常用参数进行了系统比较和讨论,包括:生长轮宽度(Growth-ring Width)、年敏感度(Annual Sensitivity)、平均敏感度(Mean Sensitivity)、生长轮显著度指数(Ring Markedness Index)、晚材率(Percentage Latewood)、细胞减小率(Percentage Diminution)、脆弱性指数(Vulnerability Index)、中生形态指数(Mesomorphy Index)、生长轮类型的划分以及细胞直径与直径平均值差值的累计代数和(cumulative algebraic sum of each cell’s deviation from the mean of the radial diameters, CSDM)。生长轮定量研究的参数和方法在松柏类木化石中的应用,不仅有助于深入了解地质历史时期古气候环境信息,而且在树叶寿命推算方面也有重要应用潜力。因此,松柏类木化石生长轮的定量研究在揭示古气候、古环境和古物候学方面具有不可替代的独特优势。
