Fossil
hideFossils (from Latin fossus, literally "having been dug up") are the preserved remains or traces of animals, plants, and other organisms from the remote past. The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous (fossil-containing) rock formations and sedimentary layers (strata) is known as the fossil record. The study of fossils across geological time, how they were formed, and the evolutionary relationships between taxa (phylogeny) are some of the most important functions of the science of paleontology. Such a preserved specimen is called a "fossil" if it is older than some minimum age, most often the arbitrary date of 10,000 years ago. Hence, fossils range in age from the youngest at the start of the Holocene Epoch to the oldest from the Archaean Eon several billion years old. The observations that certain fossils were associated with certain rock strata led early geologists to recognize a geological timescale in the 19th century. The development of radiometric dating techniques in the early 20th century allowed geologists to determine the numerical or "absolute" age of the various strata and thereby the included fossils.
Like extant organisms, fossils vary in size from microscopic, such as single bacterial cells only one micrometer in diameter, to gigantic, such as dinosaurs and trees many meters long and weighing many tons. A fossil normally preserves only a portion of the deceased organism, usually that portion that was partially mineralized during life, such as the bones and teeth of vertebrates, or the chitinous exoskeletons of invertebrates. Preservation of soft tissues is rare in the fossil record. Fossils may also consist of the marks left behind by the organism while it was alive, such as the footprint or feces (coprolites) of a reptile. These types of fossil are called trace fossils (or ichnofossils), as opposed to body fossils. Finally, past life leaves some markers that cannot be seen but can be detected in the form of biochemical signals; these are known as chemofossils or biomarkers.
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News tagged with fossil
Burning coal worse for climate than clearing rain forests
Nov 26, 2009 |
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Deforestation has had a big influence on the increase of carbon dioxide (CO2) emissions in the past three centuries, but its impact is tapering off relatively. Nowadays, the burning of fossil fuels is a more crucial factor. ...
Climate experts debate strategies for reducing atmospheric carbon and future warming
Nov 25, 2009 |
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(PhysOrg.com) -- Reducing carbon dioxide to safe levels may require extracting carbon from the air, says Cornell climate researcher.
Oceans absorbing carbon dioxide more slowly, scientist finds
Space & Earth / Earth Sciences
Nov 24, 2009 |
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The world's oceans are absorbing less carbon dioxide (CO2), a Yale geophysicist has found after pooling data taken over the past 50 years. With the oceans currently absorbing over 40 percent of the CO2 emitted by human activity, ...
Intensive land management leaves Europe without carbon sinks
Space & Earth / Earth Sciences
Nov 23, 2009 |
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A new calculation of Europe's greenhouse gas balance shows that emissions of methane and nitrous oxide tip the balance and eliminate Europe's terrestrial sink of greenhouse gases.
Bioengineers succeed in producing plastic without the use of fossil fuels
Nov 23, 2009 |
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A team of pioneering South Korean scientists have succeeded in producing the polymers used for everyday plastics through bioengineering, rather than through the use of fossil fuel based chemicals. This groundbreaking research, ...
BoarCroc, RatCroc, DogCroc, DuckCroc and PancakeCroc
Other Sciences / Archaeology & Fossils
Nov 19, 2009 |
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A suite of five ancient crocs, including one with teeth like boar tusks and another with a snout like a duck's bill, have been discovered in the Sahara by National Geographic Explorer-in-Residence Paul Sereno. ...
Oceans' uptake of manmade carbon may be slowing
Space & Earth / Earth Sciences
Nov 18, 2009 |
3.8 / 5 (23) |
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The oceans play a key role in regulating climate, absorbing more than a quarter of the carbon dioxide that humans put into the air. Now, the first year-by-year accounting of this mechanism during the industrial ...
Fighting climate change by turning CO2 to stone
Nov 17, 2009 |
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(PhysOrg.com) -- While politicians debate the best ways to cut global carbon dioxide emissions, researchers at Idaho National Laboratory's Center for Advanced Energy Studies are charging ahead on a strategy ...
Fossil fuel CO2 emissions up by 29 percent since 2000
Nov 17, 2009 |
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The strongest evidence yet that the rise in atmospheric CO2 emissions continues to outstrip the ability of the world's natural 'sinks' to absorb carbon is published this week in the journal Nature Geoscience. ...
Japanese researchers film rare baby fish 'fossil'
Nov 17, 2009 |
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Japanese marine researchers said Tuesday they had found and successfully filmed a young coelacanth -- a rare type of fish known as "a living fossil" -- in deep water off Indonesia.
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Study Pits Man v Machine in Piecing Together 425-Million Years Old Jigsaw
Other Sciences / Archaeology & Fossils
Nov 16, 2009 |
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(PhysOrg.com) -- A new study pitting academic expertise against a computer in recreating a 425 million-year old jigsaw puzzle has discovered that there is no substitute for wisdom born out of experience.
New fossil plant discovery links Patagonia to New Guinea in a warmer past
Other Sciences / Archaeology & Fossils
Nov 10, 2009 |
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Fossil plants are windows to the past, providing us with clues as to what our planet looked like millions of years ago. Not only do fossils tell us which species were present before human-recorded history, ...
Argonne 'homegrown' hybrid solar cell aims for low-cost power
Nanotechnology / Nanomaterials
Nov 10, 2009 |
4.3 / 5 (12) |
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(PhysOrg.com) -- Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have refined a technique to manufacture solar cells by creating tubes of semiconducting material and then "growing" ...
Ancient penguin DNA raises doubts about accuracy of genetic dating techniques
Nov 10, 2009 |
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Penguins that died 44,000 years ago in Antarctica have provided extraordinary frozen DNA samples that challenge the accuracy of traditional genetic aging measurements, and suggest those approaches have been ...
Scientists seek safe carbon dioxide storage for 'greener' power generation (w/ Video)
Nov 09, 2009 |
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The U.S. Department of Energy (DOE) has announced plans to fund research at the University of Alabama at Birmingham (UAB) School of Engineering on technologies that would help reduce greenhouse gas emissions through the capture ...
