7 results on '"Ablaev, Albert G."'
Search Results
2. EQUISETUM CF. PRATENSE (EQUISETACEAE) FROM THE MIOCENE OF YUNNAN IN SOUTHWESTERN CHINA AND ITS PALEOECOLOGICAL IMPLICATIONS.
- Author
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Yu-Ling Zhang, Ferguson, David K., Ablaev, Albert G., Yu-Fei Wang, Cheng-Sen Li, and Lei Xie
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EQUISETUM , *MIOCENE stratigraphic geology , *PHENOLOGY , *LIQUIDAMBAR , *ALDER , *HUMIDITY - Abstract
Rhizomes with tubers of Equisetum cf. pratense Ehrhart are described for the first time from the late Miocene of Lühe, Yunnan Province, southwestern China. The rhizomes consist of distinct nodes and internodes. The nodes bear one to four bunches of tubers (two to four tubers per bunch). The tubers are elliptical, rounded, ovate, or spindle shaped, and the most distal is mucronate. The occurrence of E. cf. pratense would indicate a wet habitat, and the presence of rhizomes with tubers implies that burial occurred during the late fall or winter, assuming that the fossil and its nearest living relative have similar climatic tolerances and phenology. These finds, combined with the presence of thermophilous genera Cyclobalanopsis, Castanopsis, and Liquidambar and hygrophilous elements Alnus and Taxodioxylon, indicate a warm and humid subtropical climate at Lühe in the Miocene. [ABSTRACT FROM AUTHOR]
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- 2007
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3. Comptonia naumannii (Myricaceae) from the early Miocene of Weichang, China, and the palaeobiogeographical implication of the genus
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Liang, Xiao-Qing, Wilde, Volker, Ferguson, David K., Kvaček, Zlatko, Ablaev, Albert G., Wang, Yu-Fei, and Li, Cheng-Sen
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PALEOBIOGEOGRAPHY , *MYRICACEAE , *MIOCENE paleoecology , *CENOZOIC paleobotany , *LEAF morphology , *GLOBAL cooling - Abstract
Abstract: Newly collected material of Comptonia leaves and fruits (C. naumannii and C. tymensis, respectively) from the lower Miocene of Weichang, China, are studied in detail. The leaves show great similarities in morphology and cuticular structures to those of the single extant species C. peregrina. It suggests a close genetic relationship between C. numannii and C. peregrina. Comptonia was widespread over the Northern Hemisphere during most of the Cenozoic, and obviously migrated into Asia from North America via a continental connection in the Eocene. Due to the cooling of global climate, it may have later gradually evolved into two ecotypes (thermophilous and cold tolerant). In the early Miocene C. naumannii was recorded from Northeast Asia and Alaska, but it disappeared from Alaska in the latest Miocene. The records suggest that plant exchange between Northeast Asia and North America may have ceased after the early Miocene. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
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4. Climatic change during the Palaeocene to Eocene based on fossil plants from Fushun, China
- Author
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Wang, Qing, Ferguson, David K., Feng, Guang-Ping, Ablaev, Albert G., Wang, Yu-Fei, Yang, Jian, Li, Ye-Liang, and Li, Cheng-Sen
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CLIMATE change , *PALEOCENE paleoclimatology , *EOCENE paleoclimatology , *FOSSIL plants , *PALYNOLOGY , *QUANTITATIVE research , *PALEOGENE paleoclimatology , *COEXISTENCE of species - Abstract
Abstract: By applying the Coexistence Approach (CA) to palynological data from the Laohutai, Lizigou, Guchengzi, Jijuntun and Xilutian Formations in Fushun, northeastern China, a quantitative reconstruction of the Palaeocene to Eocene climate is made. During that time, Mean Annual Temperature changed from 11.3 to 21°C, Mean Annual Precipitation from 654 to 1540mm, Mean Temperature of the Warmest Month from 19.4 to 28.2°C, Mean Temperature of the Coldest Month from 3.6 to 13.9°C, Mean Annual Range of Temperature from 12.8 to 23.5°C, Mean Maximum Monthly Precipitation from 175 to 354mm, and Mean Minimum Monthly Precipitation from 8 to 27mm. All the parameters in the five formations indicate a subtropical climate. This situation is different from the current climate at the same site, a mid-temperate and continental monsoon climate, with a Mean Annual Temperature of 6.6°C and a Mean Annual Precipitation of 804mm. In addition, the climatic parameters obtained from megafossil data (only found in the Jijuntun Formation) were analyzed and approximate those from the palynological data. The parameters from the palynological data support the view that the Palaeogene climate of Northeast Asia and North America was similar, but unlike that of Europe. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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5. The fossil record of Berberis (Berberidaceae) from the Palaeocene of NE China and interpretations of the evolution and phytogeography of the genus
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Li, Ye-Liang, Kvaček, Zlatko, Ferguson, David K., Wang, Yu-Fei, Li, Cheng-Sen, Yang, Jian, Ying, Tsun-Shen, Ablaev, Albert G., and Liu, Hai-Ming
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BARBERRIES , *PALEOCENE paleobotany , *PLANT evolution , *PHYTOGEOGRAPHY , *FOLIAR diagnosis , *OLIGOCENE paleobotany - Abstract
Abstract: Extant Berberis is a member of the basal eudicots with a South America (group Australes)-Old World (group Septentrionales) disjunctive distribution pattern. Different hypotheses have been proposed to explain the formation of this pattern. Recent molecular studies suggest that this pattern was caused by a vicariance event in the Cretaceous. More fossil evidence is required to evaluate these hypotheses. Here a new species of Berberis from the Palaeocene Wuyun flora is established based on a detailed comparison with all other fossil and related living Berberis. The occurrence of a Palaeocene Berberis in NE China and other fossil data suggest that 1) the genus originated in eastern Asia, 2) the leaf venation of the genus probably evolved from pinnate to acrodromous, leaf margins from densely spinose teeth to only occasionally toothed or even entire, 3) the genus would appear to have migrated from eastern Asia to North America in the Oligocene, via Beringia. Berberis probably arrived in Europe from Asia during the late Oligocene when Eurasia was reunited after the retreat of the Turgai Straits. Berberis could have migrated to India from eastern Asia, arriving before the last major upheaval of the Himalayas in the Pleistocene. [Copyright &y& Elsevier]
- Published
- 2010
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6. The Phytogeography of the extinct angiosperm Nordenskioeldia (Trochodendraceae) and its response to climate changes
- Author
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Wang, Yan-Hui, Ferguson, David K., Feng, Guang-Ping, Wang, Yu-Fei, Zhilin, Sergey G., Li, Cheng-Sen, Svetlana, Popova-Tselenkova, Yang, Jian, and Ablaev, Albert G.
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CLIMATIC factors of phytogeography , *EXTINCT plants , *FOSSIL angiosperms , *TROCHODENDRACEAE , *CLIMATE change , *DISJUNCT plants , *PLANT morphology , *CENOZOIC paleobotany - Abstract
Abstract: Elucidating the spatio-temporal distributions of terrestrial plants is a key for interpreting the origin of distribution patterns and the tempo of intercontinental disjunction. Nordenskioeldia was distributed in eastern Asia and North America from the Late Cretaceous to the Miocene. Its fossil record provides important information on former patterns of disjunction and dispersal in the Northern Hemisphere. New specimens from the Paleocene of China allow us to further extend the history of the group and provide the impetus to review its distribution in space and time. The comparative morphological survey on fossil Nordenskioeldia found in the Paleocene sediments in both eastern Asia and North America confirms that they belonged to the same morpho-species, which indicates a close floristic continuity between both continents due to land connection available during that time. The spatio-temporal distributions of Nordenskioeldia indicate that the taxon probably expanded eastward from eastern Asia into North America by the end of Early/Middle Maastrichtian, subsequently colonized Greenland, northeastern North America and Spitsbergen in the Early Paleocene, and finally became extinct in the Miocene. The fluctuations in its northern limits took place in response to climate changes: warming from the Paleocene to the Eocene, cooling during the Eocene–Oligocene and amelioration during the Late Oligocene–Mid-Miocene. [Copyright &y& Elsevier]
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- 2009
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7. Early Miocene vegetation and climate in Weichang District, North China
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Li, Jin-Feng, Ferguson, David K., Yang, Jian, Feng, Guang-Ping, Ablaev, Albert G., Wang, Yu-Fei, and Li, Cheng-Sen
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MIOCENE paleobotany , *MIOCENE stratigraphic geology , *PALEOCLIMATOLOGY , *PALYNOLOGY , *VEGETATION & climate , *METEOROLOGICAL precipitation , *ATMOSPHERIC temperature , *ARCHAEOLOGICAL finds - Abstract
Abstract: The Early Miocene palynological assemblage of Guangfayong (GFY) in the Weichang District, Hebei Province, China has been studied. It consists of 48 palynomorphs belonging to 39 families, with pollen and spores belonging to angiosperms (28.9%), gymnosperms (59.9%), ferns (10.8%) and other elements (0.5%). Based on the palynological assemblages of GFY and Wuluogong (WLG), another locality in the Weichang District, the Early Miocene vegetation of the Weichang District, was characterized by a mixed temperate forest of conifers (e.g. Pinus, Picea, Tsuga) and broad-leaved trees (e.g. Betula, Alnus), with some subtropical plants (e.g. Carya). The palaeoclimatic parameters of Guangfayong were obtained by applying the Coexistence Approach: the mean annual temperature from 7.8 to 14.9 °C, the difference of temperature between the coldest and warmest months from 14.2 to 23 °C, the mean temperature of the coldest month from −3 to 5.9 °C, the mean temperature of the warmest month from 23.5 to 25.4 °C, the mean annual precipitation from 658.7 to 1389.4 mm, the minimum monthly precipitation from 7.6 to 16.4 mm, and the maximum monthly precipitation from 161.4 to 205.9 mm. It suggests a warm temperate to subtropical climate in Weichang District, similar to that of present-day Zhaojue City, Sichuan Province in the Yangtze River Valley. When the palaeoclimatic parameters were compared with those of Middle Miocene Shanwang Basin, it would seem that the temperature and precipitation were a little higher in the Middle Miocene of eastern China. However, if the latitudinal temperature gradient at that time is considered, the median temperature values of GFY of Early Miocene and Shanwang of Mid-Miocene were similar. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF
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