نتایج جستجو برای: fossils
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Patterns of origination and evolution of early complex life on this planet are largely interpreted from the fossils of the Precambrian soft-bodied Ediacara Biota. These fossils occur globally and represent a diverse suite of organisms living in marine environments. Although these exceptionally preserved fossil assemblages are typically difficult to reconcile with modern phyla, examination of th...
Progress in paleoanthropology is impeded when new fossil materials are published but unavailable for comparative study, as is too often the case. In this commentary, we review the stages of description and analysis that new fossils must undergo and conclude that it is disingenuous to argue that fossils have not been properly "published" when descriptions and new names formulated in accordance w...
upper devonian sediments of the kuh-e zard area northwest of zefreh, central iran, arecomposed mainly of brown and grey limestones with sandstone and shale intercalations. they contain tracefossils such as chondrites isp., diplocraterion parallelum, fustiglyphus annulatus, lockeia isp., phycodesisp., and taenidium barretti. these trace fossils indicate a shallow marine environment
It is widely believed that fossils are of fundamental importance in reconstructing phylogeny (e.g. 24, 28). Simpson (52, p. 83), for example, argued "fossils provide tl?,e soundest basis for evolutionary classification." Although phylogenies of many groups have been reconstructed using morphological or chemical characters of extant organisms alone, it is often noted that fossils would have been...
Developing a detailed estimate of plant phylogeny is the key first step toward a more sophisticated and particularized understanding of plant evolution. At many levels in the hierarchy of plant life, it will be impossible to develop an adequate understanding of plant phylogeny without taking into account the additional diversity provided by fossil plants. This is especially the case for relativ...
* CSIC, Museo Nacional de Ciencias Naturales, c. José Gutiérrez Abascal 2, 28006 Madrid. [email protected] Abstract The fossil deer (Cervidae, Mammalia) from Cueva Victoria are described and compared to the other Pleistocene deer from Europe. These fossils belong to a large and a mid-sized species. The large species, represented by 153 fossils, including antlers, teeth and limb bones, is di...
PREMISE OF THE STUDY Fossilized seeds similar to Cissus (Vitaceae) have been recognized from the Miocene of Kenya, though some were previously assigned to the Menispermaceae. We undertook a comparative survey of extant African Cissus seeds to identify the fossils and consider their implications for the evolution and biogeography of Cissus and for African early Miocene paleoenvironments. METHO...
—Because of the fragmentary preservation of the earliest Cooksonia-like terrestrial plant macrofossils, younger Devonian fossils with complete anatomical preservation and documented gametophytes often have received greater attention concerning the early evolution of vascular plants and the alternation of generations. Despite preservational deficits, however, possible physiologies of Cooksonia-l...
The Talbragar Fish Bed is one of Australia's most important Jurassic deposits for freshwater fishes, land plants and aquatic and terrestrial insects. The site has yielded many well preserved fossils, which has led to the formal description of numerous new species and higher taxa. The excellent preservation of many fossils has allowed detailed anatomical studies, e.g. of the early teleost fish C...
New ages for flowstone, sediments and fossil bones from the Dinaledi Chamber are presented. We combined optically stimulated luminescence dating of sediments with U-Th and palaeomagnetic analyses of flowstones to establish that all sediments containing Homo naledi fossils can be allocated to a single stratigraphic entity (sub-unit 3b), interpreted to be deposited between 236 ka and 414 ka. This...
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