The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Rainer R Schoch - One of the best experts on this subject based on the ideXlab platform.
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a tiny new middle triassic stem lepidosauromorph from germany implications for the early evolution of lepidosauromorphs and the vellberg Fauna
Scientific Reports, 2020Co-Authors: Gabriela Sobral, Tiago R Simoes, Rainer R SchochAbstract:The Middle Triassic was a time of major changes in tetrapod Faunas worldwide, but the fossil record for this interval is largely obscure for terrestrial Faunas. This poses a severe limitation to our understanding on the earliest stages of diversification of lineages representing some of the most diverse Faunas in the world today, such as lepidosauromorphs (e.g., lizards and tuataras). Here, we report a tiny new lepidosauromorph from the Middle Triassic from Vellberg (Germany), which combines a mosaic of features from both early evolving squamates and rhynchocephalians, such as the simultaneous occurrence of a splenial bone and partial development of acrodonty. Phylogenetic analyses applying different optimality criteria, and combined morphological and molecular data, consistently recover the new taxon as a stem-lepidosauromorph, implying stem-lepidosauromorph species coinhabited areas comprising today’s central Europe at the same time as the earliest known rhynchocephalians and squamates. It further demonstrates a more complex evolutionary scenario for dental evolution in early lepidosauromorphs, with independent acquisitions of acrodonty early in their evolutionary history. The small size of most terrestrial vertebrates from Vellberg is conspicuous, contrasting to younger Triassic deposits worldwide, but comparable to Early Triassic Faunas, suggesting a potential long-lasting Lilliput effect in this Fauna.
John E Newington - One of the best experts on this subject based on the ideXlab platform.
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microbiota Fauna and mesh size interactions in litter decomposition
Oikos, 2002Co-Authors: Mark A Bradford, George M Tordoff, Till Eggers, Hefin T Jones, John E NewingtonAbstract:Plant litter decomposition is a key process in carbon and nutrient cycling. The critical role of soil-Faunal community composition in decomposition has been demonstrated using different mesh size litterbags to control exposure of litter to different Faunal size classes. However, the Faunal community surrounding the litterbags has not been manipulated despite potentially large indirect effects of their activity on biotic and abiotic processes that control litter decomposition at the habitat-scale. We combined microcosm and litterbag techniques to facilitate a more comprehensive understanding of the role of direct and indirect effects of soil-Faunal community composition on litter decomposition. We placed litterbags of three mesh sizes across model grassland miniecosystems manipulated to enable communities containing 1) microFauna; 2) micro- and meso-Fauna; 3) micro-, meso- and macro-Fauna. All communities contained bacteria and fungi. The approach permitted correction of mesh size artefacts inherent to field studies. Indirect effects have been divided into two separate terms, direct-indirect effects and indirect effects. Decomposition in micromesh litterbags was significantly decreased by the indirect effects of meso- and macro-Fauna. In macroFauna communities, increased mesh size significantly increased decomposition through mesh size per se and Faunal effects. Relative effects of manipulated Faunal community composition on litter mass loss and C:N ratio were equivalent for green and senesced litter. The presence of meso- and macro-Fauna increased litter decomposition rate overall despite inhibiting decomposition by microFauna, bacteria and fungi through indirect effects.
Gabriela Sobral - One of the best experts on this subject based on the ideXlab platform.
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a tiny new middle triassic stem lepidosauromorph from germany implications for the early evolution of lepidosauromorphs and the vellberg Fauna
Scientific Reports, 2020Co-Authors: Gabriela Sobral, Tiago R Simoes, Rainer R SchochAbstract:The Middle Triassic was a time of major changes in tetrapod Faunas worldwide, but the fossil record for this interval is largely obscure for terrestrial Faunas. This poses a severe limitation to our understanding on the earliest stages of diversification of lineages representing some of the most diverse Faunas in the world today, such as lepidosauromorphs (e.g., lizards and tuataras). Here, we report a tiny new lepidosauromorph from the Middle Triassic from Vellberg (Germany), which combines a mosaic of features from both early evolving squamates and rhynchocephalians, such as the simultaneous occurrence of a splenial bone and partial development of acrodonty. Phylogenetic analyses applying different optimality criteria, and combined morphological and molecular data, consistently recover the new taxon as a stem-lepidosauromorph, implying stem-lepidosauromorph species coinhabited areas comprising today’s central Europe at the same time as the earliest known rhynchocephalians and squamates. It further demonstrates a more complex evolutionary scenario for dental evolution in early lepidosauromorphs, with independent acquisitions of acrodonty early in their evolutionary history. The small size of most terrestrial vertebrates from Vellberg is conspicuous, contrasting to younger Triassic deposits worldwide, but comparable to Early Triassic Faunas, suggesting a potential long-lasting Lilliput effect in this Fauna.
T R Seastedt - One of the best experts on this subject based on the ideXlab platform.
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soil Fauna and plant litter decomposition in tropical and subalpine forests
Ecology, 2001Co-Authors: Grizelle Gonzalez, T R SeastedtAbstract:The decomposition of plant residues is influenced by their chemical com- position, the physical-chemical environment, and the decomposer organisms. Most studies interested in latitudinal gradients of decomposition have focused on substrate quality and climate effects on decomposition, and have excluded explicit recognition of the soil or- ganisms involved in the process. To test whether soil Fauna exhibit different effects under diverse climates or substrates, we quantified decomposition rates and N fluxes in control and Fauna-excluded treatments with litterbags containing relatively high-quality (Quercus gambehii) and low-quality (Cecropia scheberiana) litter in sites representing large differ- ences in climate as measured by AET (actual evapotranspiration). Two subtropical sites included a wet and a dry forest, and two temperate sites included north- and south-facing subalpine forests. We found that: (1) all three factors (climate, substrate quality, and soil Fauna) independently influenced the decomposition rate of plant litter in the tropical and subalpine forests; (2) Faunal effects on decomposition rates and N mineralization of Q. gambelii and C. scheberiana were consistently higher in the tropical wet forest than in the tropical dry and subalpine forests; (3) there was no significant interaction of Fauna and litter species on the annual decay rates; and (4) the density (numbers per gram of dry litter) of total Fauna was highest in the tropical wet forest, intermediate in the subalpine forests, and lowest in the tropical dry forest. Our results indicate that soil Fauna have a dispro- portionately larger effect on litter decomposition in a tropical wet forest than in a tropical dry or a subalpine forest. The annual decay rates of Q. gambelii and C. scheberiana are not influenced differentially by the soil Fauna in the tropical and subalpine forests.
Mark A Bradford - One of the best experts on this subject based on the ideXlab platform.
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microbiota Fauna and mesh size interactions in litter decomposition
Oikos, 2002Co-Authors: Mark A Bradford, George M Tordoff, Till Eggers, Hefin T Jones, John E NewingtonAbstract:Plant litter decomposition is a key process in carbon and nutrient cycling. The critical role of soil-Faunal community composition in decomposition has been demonstrated using different mesh size litterbags to control exposure of litter to different Faunal size classes. However, the Faunal community surrounding the litterbags has not been manipulated despite potentially large indirect effects of their activity on biotic and abiotic processes that control litter decomposition at the habitat-scale. We combined microcosm and litterbag techniques to facilitate a more comprehensive understanding of the role of direct and indirect effects of soil-Faunal community composition on litter decomposition. We placed litterbags of three mesh sizes across model grassland miniecosystems manipulated to enable communities containing 1) microFauna; 2) micro- and meso-Fauna; 3) micro-, meso- and macro-Fauna. All communities contained bacteria and fungi. The approach permitted correction of mesh size artefacts inherent to field studies. Indirect effects have been divided into two separate terms, direct-indirect effects and indirect effects. Decomposition in micromesh litterbags was significantly decreased by the indirect effects of meso- and macro-Fauna. In macroFauna communities, increased mesh size significantly increased decomposition through mesh size per se and Faunal effects. Relative effects of manipulated Faunal community composition on litter mass loss and C:N ratio were equivalent for green and senesced litter. The presence of meso- and macro-Fauna increased litter decomposition rate overall despite inhibiting decomposition by microFauna, bacteria and fungi through indirect effects.
