نتایج جستجو برای: carboniferous
تعداد نتایج: 2050 فیلتر نتایج به سال:
Lobopodians, a nonmonophyletic assemblage of worm-shaped soft-bodied animals most closely related to arthropods, show two major morphotypes: long-legged and short-legged forms. The morphotype with stubby, conical legs has a long evolutionary history, from the early Cambrian through the Carboniferous, including the living onychophorans and tardigrades. Species with tubular lobopods exceeding the...
Geology and Metallogeny of the Drina-ivanjica Metamorphic Complex in Eastern Bosnia – Western Serbia
This paper gives a critical review of all relevant, published works on the stratigraphy, tectonics, magmatism, metamorphism and metallogeny of the metamorphic complex of the Drina-Ivanjica Formation in eastern Bosnia-western Serbia. Special attention was paid to all unresolved or controversial issues in geology and metallogeny of this area. The basic controversial geological problem is the ques...
The distribution and dispersal histories of Eurypterida are examined in a phylogenetic and palaeogeographic context. It is suggested that all the eurypterid clades originated and had most of their evolutionary history on the palaeocontinents of Laurentia, Baltica, Avalonia, the Rheno–Hercynian Terrane and some presence in Siberia. The Siluro–Devonian Stylonurina and the eurypterine superfamilie...
We have studied the syn-kinematic very low-grade metamorphism in a polyphase Variscan deformed region using X-ray diffraction techniques. Two phases of regional metamorphism are related to their respective episodes of penetrative deformation in the southern Central Iberian Zone. The data obtained suggest that the rocks did not reach metamorphic equilibrium, but strain favoured the progress of m...
New megafossil and microfossil data indicate four episodes in the diversification of Silurian-Early Carboniferous land plants of South China, a relatively continuous regional record. Plant diversity increased throughout, but the rising curve was punctuated by three major falls. There were peaks of origination in the Ludlow-Pragian, Givetian, late Famennian and Visean and peaks of extinction in ...
Natural variations in the tropospheric CH4 concentration, excluding short bursts from geospheric reservoirs, have been estimated for the past 400 Ma by scaling a wetland CH4 emission estimate for the middle Pliocene (ca. 3.6–2.6 Ma) by the relative rate of coal basin deposition at any given time in the past. Wetland CH4 fluxes were used as inputs into the Cambridge 2-D chemistry-transport model...
Famennian tabulate corals were very rare worldwide, and their biodiversity was relatively low. Here we report a unique tabulate fauna from the mid- and late Famennian of the western part of the Holy Cross Mountains (Kowala and Ostrówka), Poland. We describe eight species (four of them new, namely ?Michelinia vinni sp. nov., Thamnoptychia mistiaeni sp. nov., Syringopora kowalensis sp. nov. and S...
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