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
Increasing carbon dioxide and decreasing oxygen make it harder for deep-sea animals to 'breathe'
Space & Earth / Earth Sciences
Apr 17, 2009 |
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(PhysOrg.com) -- New calculations made by marine chemists from the Monterey Bay Aquarium Research Institute (MBARI) suggest that low-oxygen "dead zones" in the ocean could expand significantly over the next ...
Chicago Installs Solar Powered Charging Station for Electric Vehicles
Apr 10, 2009 |
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(PhysOrg.com) -- One of the biggest arguments that some have made against plug-in electric vehicles is that they still promote the use of fossil fuels. When you have to plug in a car for a charge, the electricity ...
Going green: Entire Swedish city switches to biofuels to become environmentally friendly
Mar 08, 2009 |
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Though a fraction of Chicago's size, this industrial city in southeast Sweden has plenty of similarities with it, including a long, snowy winter and a football team the town's crazy about.
House Democrats unveil sweeping plan to reshape energy in America
Apr 01, 2009 |
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Democrats in the House of Representatives on Tuesday announced a sweeping plan to change how the nation produces and uses energy in order to reduce the risk of dangerous climate change.
Solar Roadways Awarded DOT Contract to Pave Roads with Solar Cells
Sep 07, 2009 |
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(PhysOrg.com) -- In a first step toward turning highways into energy-generating solar panels, the Sagle, Idaho-based startup Solar Roadways has recently received a $100,000 grant from the US Department of ...
To meet climate goal, only quarter of fossil fuels can be used: study
Apr 29, 2009 |
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Meeting a widely-supported goal to tackle global warming means that humanity will be able to burn less than a quarter of the proven reserves of fossil fuels by 2050, a study released on Wednesday said.
Paleontologists brought to tears, laughter by Creation Museum
Jun 30, 2009 |
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For a group of paleontologists, a tour of the Creation Museum seemed like a great tongue-in-cheek way to cap off a serious conference.
How a Solar-Hydrogen Economy Could Supply the World's Energy Needs
Aug 24, 2009 |
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(PhysOrg.com) -- As the world's oil supply continues to dry out every day, the question of what will replace oil and other fossil fuels is becoming more and more urgent. According to the World Coal Institute, ...
Before 'Lucy,' there was 'Ardi': Oldest hominid skeleton provides new evidence for human evolution (w/ Video)
Other Sciences / Archaeology & Fossils
Oct 01, 2009 |
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In a special issue of Science, an international team of scientists has for the first time thoroughly described Ardipithecus ramidus, a hominid species that lived 4.4 million years ago in what is now Ethiop ...
Extinction risk to plant biodiversity may occur at lower levels of atmospheric CO2 than previously considered
Jun 29, 2009 |
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(PhysOrg.com) -- Scientists have traced a sudden collapse in plant biodiversity in ancient Greenland, some 200 million years ago, to a relatively small rise in atmospheric carbon dioxide which caused a rise in the Earth’s ...
$21 Billion Orbiting Solar Array will Beam Electricity to Earth
Sep 15, 2009 |
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(PhysOrg.com) -- The Japanese are preparing to develop a two trillion yen (approximately $21 billion USD) space solar project that will beam electricity from space in the form of microwaves or lasers to around ...
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 ...
New ancient fungus finding suggests world's forests were wiped out in global catastrophe
Space & Earth / Earth Sciences
Oct 01, 2009 |
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(PhysOrg.com) -- Scientists beleive extinct fungus species capitalised on a world-wide disaster and thrived on early Earth.
Shifting the world to 100 percent clean, renewable energy as early as 2030 -- here are the numbers
Oct 19, 2009 |
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Most of the technology needed to shift the world from fossil fuel to clean, renewable energy already exists. Implementing that technology requires overcoming obstacles in planning and politics, but doing so ...
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 ...
