نتایج جستجو برای: plant fossils
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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...
A new species of aquatic plant, Scutifolium jordanicum gen. et sp. nov., Taylor, Brenner & Basha, is described from the Albian of Jordan. The leaves are microphyllous with a symmetrical, elliptical to suborbiculate shape, convex to rounded apex and base, and actinodromous to palinactinodromous primary venation. The peltate, centrally attached petioles are narrow, elongate, and alternately arran...
In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: a b s t r a c t a r t i c l e i n f o Exceptional fossil preservation may require not only exceptional places, but exception...
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
At a symposium honoring the 50th anniversary of University Chicago, Gilbert Cady introduced concept phyterals as means distinguishing actual plant fossils from macerals composed fossils. In this sense, vitrinite and fusinite, while distinct macerals, are viewed same phyteral. contrast to such process-induced in vs. phyterals, funginite, regardless rank, age, or type fungus producing structure, ...
Most implementations of molecular clocks require resolved topologies. However, one of the Bayesian relaxed clock approaches accepts input topologies that include polytomies. We explored the effects of resolved and polytomous input topologies in a rate-heterogeneous sequence data set for Gnetum, a member of the seed plant lineage Gnetales. Gnetum has 10 species in South America, 1 in tropical We...
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...
* 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...
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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