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New schizolepis Fossils from the Early Cretaceous in Inner Mongolia, china and its Phylogenetic Position

Acta Geologica sinica(English Edition) 2013年第5期87卷 1250-1263页

作者： XU Xiaohui LI Ruiyun DONG Chong WANG Qiujun JIN Peihong sUN Bainian school of earth sciences&key laboratory of mineral resources in western china (gansu province) Lanzhou University

Three schizolepis species collected from the Lower Cretaceous layer of the Huolinhe Basin, Inner Mongolia, china are described. These fossils are schizolepis longipetiolus Xu XH et sun BN sp. nov., which is a new species, schizolepis cf. heilongjiangensis Zheng et Zhang, and schizolepis neimengensis Deng. The new species is a well-preserved female cone, slender and cylindrical in shape. The seed-scale complexes have long petioles and are arranged on the cone axis loosely and helically. The seed scales are divided into two lobes from the base. Each lobe is semicircular or elongate ligulate in shape, widest at the middle or the lower middle part, with an obtuse or bluntly pointed apex. The inner margin is almost straight and the outer margin is strongly arched. On the surface of the lobe, there are longitudinal and somewhat radial striations from the base to the margin. The seed is borne on the adaxial surface at the base or middle of each lobe. schizolepis was estabfished in 1847, and, although more than twenty species have been discovered and reported, its phylogenetic position is controversial because of the imperfection of fossils. Most authors have considered there to be a close evolutionary relationship between schizolepis and extant Pinaceae. Here, we analyze characteristics and compare schizolepis with Picea crassifolia Kom, which is morphologically most similar to schizolepis. The results indicate that the genus probably has a distant evolutionary relationship with extant Pinaceae. A detailed statistical analysis of the global paleogeographic distribution of schizolepis showed that all the fossils of this genus appeared in strata ranging from the Upper Triassic to the Lower Cretaceous in the North Hemisphere, being rare in the Upper Triassic and Lower Jurassic, but being very common from the Middle Jurassic to the Lower Cretaceous, and particularly abundant in the Lower Cretaceous. According to the statistical results, we speculate that the genus originated i

关键词： schizolepis systematic evolution paleogeographic distribution Early Cretaceous cause of extinction Inner Mongolia

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Bamboo Leaf and Pollen Fossils from the Late Miocene of Eastern Zhejiang,china and their Phytogeological significance

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Acta Geologica sinica(English Edition) 2014年第4期88卷 1066-1083页

作者： WANG Qiujun MA Fujun YANG Yi DONG Junling WANG Haofei LI Ruiyun XU Xiaohui sUN Bainian school of earth sciences & key laboratory of mineral resources in western china (gansu province) Lanzhou University

Fossil bamboo leaves and pollen from Upper Miocene deposits of the shengxian Formation in Tiantai and Ninghai counties, eastern Zhejiang, china represent a rare record in Asia. The distinctive pseudopetiole and parallel venation of the leaf blades and the clearly thickened annulus of the pollen aperture place them in the subfamily Bambusoideae. Morphological analysis supports the determination of these fossil leaves as belonging to the genus Bambusium and two new species are described. Bambusium latipseudopetiolus Q.J. Wang et B.N. sun sp. nov. has a distinctly wide pseudopetiole of 0.23 cm in width and 0.40 cm in length, several vascular bundles on parallel veins, and 5-8 lateral veins on both sides of the midrib. Bambusium longipseudopetiolus Q.J. Wang et B.N. sun sp. nov. has a distinctly long pseudopetiole of 0.60 cm in length and 0.10 cm in width, several vascular bundles on the pseudopetiole, and 6 lateral veins on both sides of the midrib. Pollen grains from the same layer provide additional evidence of bamboos. They are characterized by 32.0-51.0 μm in diameter, a round pore 3.0-4.0 μm in diameter with a broad thickened annulus 2.5-3.5 μm around, and several conspicuous secondary folds on the exine surface. The morphological analysis leads to their assignment to Graminidites bambusoides stuchlik. These fossils are important for the study of bamboo phytogeography in china. They demonstrate that there were bamboos growing in southeastern china during the Late Miocene and that bamboos in Zhejiang begin to diversify no later than the Late Miocene. In combination with bamboo fossils from other places, it seems that bamboos had a wide distribution across southern china during the Miocene, ranging from southwestern Yun＇nan to southeastern Zhejiang.

关键词： Paleobotany Palynology Phytogeography Bambusoideae Late Miocene Zhejiang province

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A New species of Ginkgo with Male Cones and Pollen Grains in situ from the Middle Jurassic of Eastern Xinjiang,china

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Acta Geologica sinica(English Edition) 2017年第1期91卷 9-21页

作者： WANG Zixi sUN Fankai JIN Peihong CHEN Yingquan CHEN Jingwei DENG Peng YANG Guolin sUN Bainian school of earth sciences & key laboratory of mineral resources in western china (gansu province) Lanzhou University key laboratory of Petroleum resources Gansu ProvinceChinese Academy of Sciences

Well-preserved Ginkgo pollen organs are analyzed from the Middle Jurassic Xishanyao Formation of the Turpan–Hami Basin, Xinjiang Uygur Autonomous Region, northwestern china, and are described as a new species, Ginkgo hamiensis Z.X. Wang et B.N. sun sp. nov. The immature male cones are cylindrical and catkin-like, with two longitudinal stripes on the stalk. The pollen sacs are shaped like a long oval with two pollen sacs fused together for each microsporophyll, and the microsporophyll tip is a triangular cystidium. The pollen grains are oblong or fusiform and monocolpate; both ends are blunt or sharp. By comparison with previously reported fossil records of Ginkgo plants, we determined that the current fossils are different from all other reported species; thus, the present fossil is referred to as a new species of Ginkgo. The reproductive organs of the Ginkgo fossils described herein can provide valuable information for the study of Ginkgo plants. Further, there are two probable evolutionary trends in the Ginkgo pollen cones. One trend is that the number of pollen sacs changed from three or four during the Jurassic and Cretaceous to two at the present day; the other is that the number of pollen sacs has remained two from the Middle Jurassic to the present day. In addition, the pollen cones described herein are similar to the pollen cones of the extant Ginkgo, which strongly indicates that the morphology of Ginkgo plants may have remained highly conserved over millions of years.

关键词： Ginkgo hamiensis Pollen cones Middle Jurassic Xinjiang Uygur Autonomous Region systematic evolution

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Carbon and Oxygen Isotopic Compositions: How Lacustrine Environmental Factors Respond in Northwestern and Northeastern china

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Acta Geologica sinica(English Edition) 2013年第5期87卷 1344-1354页

作者： ZHANG Chengjun FAN Rong LI Jun steffen MIsCHKE laise DEMBELE HU Xiaolan school of earth sciences&key laboratory of mineral resources in western china (gansu province) Lanzhou University College of Resource and Environmental sciences Lanzhou University Institute of earth and Environmental science University of Potsdam

surface lake sediments, 28 from Hoh XU, 24 from northeastern china, 99 from Lake Bosten, 31 from Ulungur and 26 from Heihai were collected to determine δ13C and δ18O values. Considering the impact factors, conductivity, alkalinity, pH, TOC, C/N and carbonate-content in the sediments, CI, P, s, and metal element ratios of Mg/Ca, sr/Ca, Fe/Mn of bulk sediments as environmental variables enable evaluation of their influences on δ13C and δ18O using principal component analysis （PCA） method. The closure and residence time of lakes can influence the correlation between δ13C and δ18O. Lake water will change from fresh to brackish with increasing reduction and eutrophication effects. Mg/Ca in the bulk sediment indicates the characteristic of residence time, sr/Ca and Fe/Mn infer the salinity of lakes. Carbonate formation processes and types can influence the 6~3C--~1so correlation. ~180 will be heavier from Mg-calcite and aragonite formed in a high-salinity water body than calcite formed in freshwater conditions. When carbonate content is less than 30%, there is no relationship with either 613C or 6180, and also none between δ13C and δ18O. More than 30%, carbonate content, however, co-varies highly to δ13C and δ18O, and there is also a high correlation between δ13C and δ18O. Vegetation conditions and primary productivity of lakes can influence the characteristics of δ13C and δ18O, and their co-variance. Total organic matter content （TOC） in the sediments is higher with more terrestrial and submerged plants infilling. In northeastern and northwestern china, when organic matter in the lake sediments comes from endogenous floating organisms and algae, the δ13C value is high. δ13C is in the range of-4‰ to 0‰ when organic matter comes mainly from floating organisms （C/N〈6）; in the range of-4‰ to 8‰ when organic matter comes from diatoms （C/N=6 to 8）; and -8‰ to -4‰ when organic matter comes from aquatic and terrestrial plants （C/N〉8）.

关键词： Limnology isotopic analysis carbonates organic matter PCA Tibet Xinjiang,Northeastern china

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sedimentary and OsL dating evidence for the development of the present Hobq desert landscape, northern china

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science china earth sciences 2013年第12期56卷 2037-2044页

作者： FAN YuXin CHEN XiaoLong FAN TianLai JIN Ming LIU JianBao CHEN FaHu key laboratory of western china's Environmental systems (MOE) Lanzhou University school of earth sciences & key laboratory of mineral resources in western china (gansu province) Lanzhou University

The sedimentary sequence and landscape of the Hobq desert was observed through twelve profiles along five N-s sections extending through the entire *** sands were found to overlie the alluvial,diluvial,and lacustrine sediments in this *** stimulated luminescence(OsL)dating results were obtained from post-IR OsL signals of quartz fractions of sand samples at the bottom of sand dunes and hills by using the Double-sAR *** OsL ages reveal that the latest sand accumulation began around 19 ka in the northwestern part and 9 ka in the eastern part of the Hobq *** 7 ka,the sand accumulation was strengthened and extended southward and northward 2 ka to develop the present desert *** study suggests that the aeolian sand accumulation around 19,9 and 7 ka resulted from the weakening of the Asian summer monsoon over this ***,the rapid development of the present Hobq desert landscape since 2 ka was likely triggered by human activities in this desert.

关键词： Hobq Desert OsL dating Last Glacial Maximum Holocene environmental and climatic change

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A New Material of Lindera (Lauraceae) of the Late Pliocene from Tengchong, Yunnan and the Genus' Biogeography significance

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Acta Geologica sinica(English Edition) 2013年第3期87卷 690-706页

作者： DAO Kequn CHEN Junlin JIN Peihong DONG Chong YANG Yi XU Xiaohui WU Jingyu XIE sanping LIN Zhicheng sUN Bainian school of earth sciences and key laboratory of mineral resources in western china (Gansu Province) Lanzhou University school of Petroleum Engineering Chongqing University of Science & Technology

Lindera is a large genus of graceful, pleasantly scented and common native trees and shrubs of southern china and neighboring regions of sE Asia. There is a well-documented Cenozoic fossil record not only in these regions but also from elsewhere. A new fossil leaf record has been found in diatomite beds from the Upper Pliocene Mangbang Formation of Tuantian, Tengchong County, Yunnan. The leaves are identified and assigned to Lindera acuminatissima K. Q. Dao et B. N. sun sp. nov., by comparing their leaf architecture and epidermal characteristics with those of 51 extant Lauraceae species and with 15 known fossil Lindera taxa. The specimens have well-preserved cuticles, with typical leaf architecture and epidermal characteristics of the Lanraceae, including entire leaf margin, intramarginal veins, basal ternate acrodromous primary veins, one-cell trichome base, paracytic stomatal apparatus, sunken guard cells, subsidiary hardly staining cells and presence of oil cells. These characteristics are consistent with Lindera sect. Daphnidium but are different from reported fossil and extant species of Lindera. The cuticles of Lindera are fragile and delicate with only three Lindera fossils reported based on this tissue. In terms of paleobiogeography, the fossil record indicates that Lindera is distributed in high- to mid-latitude regions of the Late Cretaceous to Paleocene northern hemisphere. Coincidentally, the records of Lindera located on both sides of the Bering Land Bridge possibly support the hypothesis that ancient plants extended via transcontinental exchanges through the Bering Corridor. In the Eocene, ancient Lindera spread to Europe through the Northern Degeer Route and the southern Thulian Route. At the same time, ancient Lindera spread into Central Asia. Climatic changes and tectonization since the Neogene prevented the propagation of Lindera throughout Asia, North America and Europe, and hence the distribution areas have just regressed to the low-latitude regi

关键词： paleobotany fossil leaves cuticle biogeography Piacenzian Yunnan province

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A New species of Cupressinocladus from the Lower Cretaceous of Guyang Basin,Inner Mongolia,china and Cluster Analysis

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Acta Geologica sinica(English Edition) 2017年第4期91卷 1200-1214页

作者： JIN Peihong MAO Teng DONG Junling WANG Zixi sUN Mingxuan XU Xiaohui DU Baoxia sUN Bainian school of earth sciences & key laboratory of mineral resources in western china(gansu province) Lanzhou University school of Electrical Engineering and Computer science Louisiana State University

Cupressinocladus seward is a fossil genus of conifers and conifer fossils with reproductive organs are very rare. In general, it is difficult to understand the natural affinities with other conifers. In this paper, a new species, Cupressinocladus guyangensis P.H. Jin et B.N. sun sp. nov., is reported based on branches with immature female cones from the Lower Cretaceous Guyang Formation of the Guyang Basin in Inner Mongolia, northern china. The foliage shoots are decussate. Leaves are decussate, imbricate, scale-like, weakly dimorphic, and bear longitudinal glands on the abaxial view. stomata complexes are haplocheilic, monocyclic, irregularly arranged, and spread along the leaf margin. Immature female cones are subglobose with 6-8 cone scales, and three subglobose ovules arranged in a row at the base of the cone scales. Moreover, we performed cluster analysis using a statistics and machine learning toolbox for 23 fossils and extant species based on 16 morphological characters. The result implies that the new species bears a close resemblance to the extant Cupressusfunebris Endl. and might have nearest systematic affinities to it.

关键词： Cupressinocladus Immature female cone Lower Cretaceous Cluster analysis New species

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Late Miocene Pods and Leaves of Albizzia (Leguminosae:Mimosoideae) from Yunnan,sW china and Their Phytogeographic Implications

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Acta Geologica sinica(English Edition) 2017年第4期91卷 1190-1199页

作者： LI Binke XIE sanping ZHANG sihang CHEN Tianyu sHAO Yang school of earth sciences and key laboratory of mineral resources in western china(gansu province) Lanzhou University state key laboratory of Palaeobiology and stratigraphy Nanjing Institute of Geology and PaleontologyCAS

Albizzia is a leguminous genus belonging to the subfamily Mimosoideae with approximately 150 modern species, widely distributed in the tropical and subtropical regions of Asia, Africa, Australia and America. Among them, 17 species are mainly distributed in southern and southwestern china. Abundant fossils of the subfamily Mimosoideae, including leaves, pods, flowers and wood, have been reported from the Cretaceous and Paleogene strata of the Northern Hemisphere. However, Neogene records of Mimosoideae are relatively scarce. In this study, fossil pods and leaves belonging to the genus Aibizzia from the Bangmai Formation of Yunnan, china were described. They were assigned to three species, including Albizzia scalpeUiformis Guo, Li and Xie Emended, Albizzia cf. kalkora （Roxb.） Prain and Albizzia sp. The occurrence of Albizzia fossils from Lincang not only gives important information on the Neogene plant diversity from Yunnan--a worldwide famous biological hotspot--but also provides additional evidence for its phytogeographic history.

关键词： Albizzia Mimosoideae morphology Late Miocene Lincang

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Buxus Leaves from the Oligocene of Guangxi, china and Their Biogeographical significance

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Acta Geologica sinica(English Edition) 2015年第5期89卷 1453-1469页

作者： MA Fujun WANG Qiujun DONG Junling YANG Yi WANG Wenjia YAN Defei sUN Bainian school of earth sciences & key laboratory of mineral resources in western china (gansu province) Lanzhou University key laboratory of Petroleum resources Gansu Province CAS school of Geography and Tourism Guizhou Normal College key laboratory of Economic stratigraphy and Palaeogeography Nanjing Institute of Geology and Palaeontology CAS

The present paper reports two new species of Buxus from the Oligocene Ningming Formation of Guangxi, south china, on the basis of several compressed fossil *** ningmingensis *** characterized by an elliptic to ovate shape; pinnate venation with marginal secondary, long hairs on the adaxial side of the midvein base; and amphistomatic, anomocytic stomata with a prominent outer *** of these characteristics suggest a closest affinity to the living Buxus microphylla *** new species identified as Buxus preaustro-yunnanensis *** characterized by the diagnostic formation of its admedially branched tertiaries, the trunks of which are often strongly thickened by *** species is most similar to the extant Buxus *** co-occurrence of Buxus ningmingensis *** Buxus preaustro-yunnanensis *** that these two Buxus lived during the Oligocene under a warm, tropical to subtropical climate, similar to the current climate of *** findings provide the earliest fossil evidence of Buxus leaves with detailed illustrations of leaf architectural and cuticular *** occurrence of these two species indicates that Buxus began to diversify in Guangxi no later than the Oligocene.

关键词： Buxus diversification paleoclimate Oligocene Guangxi

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Middle Cretaceous pCO_2 Variation in Yumen, gansu province and its Response to the Climate Events

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Acta Geologica sinica(English Edition) 2018年第2期92卷 801-813页

作者： LEI Xiangtong DU Zhen DU Baoxia ZHANG Mingzhen sUN Bainian school of earth sciences & key laboratory of mineral resources in western china (gansu province) Lanzhou University state key laboratory of Palaeobiology and stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences key laboratory of Petroleum resources Gansu Province/Key Laboratory of Petroleum Resources Research Institute of Geology and Geophysics Chinese Academy of Sciences

The palaeo-atmospheric CO2 concentration （pCOz） variation in the Yumen, gansu province during the middle Cretaceous has been reconstructed using the newly established plant photosynthetic gas exchange mechanistic model, and the results show that the pCO2 values are in the range of about 550 -808 ppmv. The present pCO2 values are higher than the pCO2 results （531-641 ppmv） of the previous study according to the Recent standardization of the stomatal ratio method, and much lower than the pCO2 results （882-1060 ppmv） according to the Carboniferous standardization of the stomatal ratio method. The present pCOz variation is not only within the error range of GEOCARB II and GEOCARB Ill but also is similar to the reconstructed results based on the biochemistry and carbon isotope models. Besides, the present Brachyphyllum specimens were collected from four consecutive horizons of the upper Zhonggou Formation of the Hanxia section, and the reconstructed pCO2 exhibits the reconstructed pCO2 exhibits a decline trend during the late Aptian to early Albian. This decline variation is probably associated with the Oceanic Anoxic Events （OAElb） and the Cold snap event. With the combination of pCO2 during the Albian to Cenomanian recovered by the plant photosynthetic gas exchange mechanistic model, the pCO2 showed a prominent increase during the late Aptian to early Cenominian, which indicates a response to the greenhouse warming during the middle Cretaceous. Therefore, the mechanical model of the plant photosynthetic gas exchange shows a relatively strong accuracy in the reconstruction of thepCO2 and can reflect a strong relation between the atmospheric CO2 concentrations and climatic events.

关键词： pCO2 greenhouse climate plant photosynthetic gas exchange mechanical model OAElb,Cold snap

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