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
Solar power generation around the clock
Nov 05, 2009 |
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(PhysOrg.com) -- A Californian company, SolarReserve, is developing a solar power system that can store seven hours' worth of solar energy by focusing mirrors onto millions of gallons of molten salt, allowing ...
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 ...
Oceans' uptake of manmade carbon may be slowing
Space & Earth / Earth Sciences
Nov 18, 2009 |
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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 ...
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, ...
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. ...
INL develops safer, more efficient nuclear fuel for next-gen reactors
Nov 30, 2009 |
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As the nation ponders its energy choices, Americans keep asking themselves: how can the country make better use of its resources and emit fewer greenhouse gases without hurting U.S. industries? A research ...
Tesla Roadster Goes 313 Miles on a Single Charge
Nov 09, 2009 |
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(PhysOrg.com) -- Tesla is becoming synonymous with high performance electric cars. Indeed, the Tesla car company has been making efforts to create a brand of sports car that runs on electricity, and does so ...
Argonne 'homegrown' hybrid solar cell aims for low-cost power
Nanotechnology / Nanomaterials
Nov 10, 2009 |
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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 muscle tissue extracted from 18 million year old fossil
Other Sciences / Archaeology & Fossils
Nov 05, 2009 |
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(PhysOrg.com) -- Scientists have extracted organically preserved muscle tissue from an 18 million years old salamander fossil. The discovery by researchers from University College Dublin, the UK and Spain, ...
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 ...
BoarCroc, RatCroc, DogCroc, DuckCroc and PancakeCroc
Other Sciences / Archaeology & Fossils
Nov 19, 2009 |
4.9 / 5 (8) |
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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. ...
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.
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 |
3.9 / 5 (8) |
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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.
Antarctica served as climatic refuge in Earth's greatest extinction event
Space & Earth / Earth Sciences
Dec 02, 2009 |
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A new fossil species suggests that some land animals may have survived the end-Permian extinction by living in cooler climates in Antarctica. Researchers have identified a distant relative of mammals that apparently survived ...
