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The uniqueness of the flora from the remote tableaux summits of the Guayana region has been explained either as the result of a long history of evolution in isolation (Lost World hypothesis or LW) or by alternating upward and downward displacements during the glacial–interglacial Quaternary cycles (Vertical Displacement hypothesis or VD). So far, the problem has been addressed solely on the basis of present-day floristic observations. This paper faces the problem from a Quaternary palaeoecology perspective using recent palynological findings in the area, comparisons with palaeoecological records from Neotropical mountains and lowlands of similar latitude, isotopic glacial–interglacial records from marine and ice cores, and different points of view about the response of organisms to Quaternary climatic changes, with emphasis on the LGM and the debate on the existence or not of Neotropical refugia. It is concluded that both LW and VD hypotheses, together with autoecological and synecological considerations, are needed to explain the present-day specialisation and endemism of the flora from the tableaux summits. The case of a highly endemic genus (Chimantaea, Asteraceae) is analysed as an example, to illustrate the usefulness and limitations of the different arguments to account for its biogeographical pattern. Some ideas are provided for future research, including a more extensive sampling strategy, the use of molecular phylogenetics, the evaluation of the individualistic versus the community approach, and the use of island biogeography and metapopulation methods on present-day floristic data. [Copyright &y& Elsevier]

With a depositional history spanning the early Aptian to early Albian (~19 mys), the Lower Cretaceous Xinminpu Group in Jiuquan, NW China provides detailed record of an inland ecosystem responding to global climatic and environmental changes. The Xinminpu Group exhibits the most typical elements of the Jehol Biota found outside NE China, a highly diverse avifauna and a mid-Cretaceous angiosperm flora. The absence of a comprehensive stratigraphical framework for this area however limits the degree to which the unit can be interpreted relative to coeval sections and the geological records in genera. Recent fossil discoveries and radio-isotopic age data can provide a more detailed biostratigraphical and chronostratigraphical framework for Lower Cretaceous units around Jiuquan. The data complied here indicate that the Chijinpu Formation correlates with the middle-upper Yixian and lower Jiufotang formations of NE China making it early Aptian in age, and the Xiagou Formation correlates with the upper Jiufotang and Shahai formations making it late early Aptian-early Albian in age. This research further reports a novel zircon U-Pb age constraint of 112.4 ± 0.3 Ma for a basalt sample from the lowermost Zhonggou Formation, which is supported to be correlated with the Fuxin Formation of early Albian age. The Chijinpu Formation contains typical elements of the Jehol Biota, i.e. the Eosestheria - Lycoptera - Ephemeropsis trisetalis assemblage, confirming the interpretation that the Jehol Biota had reached Jiuquan during its second evolutionary stage. The Xiagou Formation contains the amphibious avifauna appearing just above OAE1a, indicating a close link between the early Ornithuromorpha evolution and early Aptian global climate changes. The Zhonggou Formation in Jiuquan records the first appearance of an angiosperm flora above OAE1b. Depositional indicators suggest a humid climate with a gradual shift to arid conditions during this time. This review paper laid foundation for the systematic study of the well-preserved Early Cretaceous ecosystem in Jiuquan, allowing to understand correlations between inland and marine environments as recorded in sediments from this critical period. • We establish the stratigraphy and time scales for the Lower Cretaceous in Jiuquan. • We review how a Cretaceous inland ecosystem responded to global climatic change. • This study summarizes the detailed fossil records for the Jehol Biota in NW China. • Robust age for the less-studied outcrops allows to test the Jehol radiations. • A close link existed between early Ornithuromorpha evolution and OAE1a. [ABSTRACT FROM AUTHOR]

• This study reviews and lists all Chinese papers on Devonian miospores. • The Late Devonian miospore diversity was greatly overestimated. • The rise of land plants and the oxygenation event are discussed. • The spore diversity is affected by both climate and sea-level changes. The microfossil-based pattern of the Devonian land plants of China is revised and discussed based on a new, comprehensive dataset. This dataset compiles the chronostratigraphical distribution of 1677 species belonging to 190 genera of spores and pollen from the primary literature, which covers the history of fossil Chinese terrestrial palynofloras. From this, we describe the patterns and biodiversity dynamics using both range-based and sample-based data to illustrate the main fluctuations of Devonian taxonomic richness, including rarefaction by filtering out uneven sampling. Results show that the apparent terrestrial palynofloral diversity of China increases progressively from the Early to Middle Devonian, with a genuine Givetian peak followed by a plateau persisting during the Late Devonian. Results further suggest that sampling effects may strongly influence the perception of biodiversity trends in China, as well as that the observed Late Devonian taxonomic diversification may have been greatly overestimated. Compiled evidence is discussed in the light of the global evolution of marine-terrestrial ecosystems. We hypothesize that the rise of Devonian floras may have played a remarkable role in an oceanic oxygenation event during this Period. [ABSTRACT FROM AUTHOR]