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
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 |
4.2 / 5 (11) |
3
(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 |
4.8 / 5 (22) |
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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 |
not rated yet |
1
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 ...
Tesla Roadster Goes 313 Miles on a Single Charge
Nov 09, 2009 |
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2
(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 ...
Ancient muscle tissue extracted from 18 million year old fossil
Other Sciences / Archaeology & Fossils
Nov 05, 2009 |
4.7 / 5 (10) |
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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, ...
Airborne nitrogen shifts aquatic nutrient limitation in pristine lakes
Space & Earth / Earth Sciences
Nov 05, 2009 |
3.3 / 5 (4) |
3
The impact of airborne nitrogen released from the burning of fossil fuels and wide-spread use of fertilizers in agriculture is much greater that previously recognized and even extends to remote alpine lakes, ...
Male sabertoothed cats were pussycats compared to macho lions
Nov 05, 2009 |
4.2 / 5 (6) |
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Despite their fearsome fangs, male sabertoothed cats may have been less aggressive than many of their feline cousins, says a new study of male-female size differences in extinct big cats.
The last European hadrosaurs lived in the Iberian Peninsula
Other Sciences / Archaeology & Fossils
Nov 05, 2009 |
4.5 / 5 (2) |
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Spanish researchers have studied the fossil record of hadrosaurs, the so-called 'duck-billed' dinosaurs, in the Iberian Peninsula for the purpose of determining that they were the last of their kind to inhabit ...
Solar power generation around the clock
Nov 05, 2009 |
4.5 / 5 (28) |
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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 ...
3 Questions: Sergey Paltsev on the costs of climate-change legislation
Nov 05, 2009 |
2.3 / 5 (6) |
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Sergey Paltsev, a principal research scientist in MIT’s Joint Program on the Science and Policy of Global Change, was the lead author of a recent report that analyzed the costs of climate legislation currently ...
T.rex's oldest ancestor identified
Other Sciences / Archaeology & Fossils
Nov 04, 2009 |
4.5 / 5 (2) |
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(PhysOrg.com) -- Remains of the oldest-known relative of T.rex have been identified, more than 100 years after being pulled out of a Gloucestershire reservoir, according to research published in the Zoological Jo ...
Portable 3-D laser technology preserves Texas dinosaur's rare footprint
Other Sciences / Archaeology & Fossils
Nov 04, 2009 |
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Using portable 3D laser technology, scientists have electronically preserved a rare 110 million-year-old fossilized dinosaur footprint that was previously excavated and built into the wall of a bandstand at a Texas courthouse ...
Mapping nutrient distributions over the Atlantic Ocean
Space & Earth / Earth Sciences
Nov 03, 2009 |
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Large-scale distributions of two important nutrient pools - dissolved organic nitrogen and dissolved organic phosphorus (DON and DOP) have been systematically mapped for the first time over the Atlantic Ocean in a study led ...
The terrible teens of T. rex
Other Sciences / Archaeology & Fossils
Nov 02, 2009 |
4.3 / 5 (4) |
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We all know adolescents get testy from time to time. Thank goodness we don't have young tyrannosaurs running around the neighborhood.
