Wednesday, September 2, 2020

Fossil

Any evidence of ancient life is called fossil. A fossil may be an organisms remains, such as plant, shells, teeth or bones. A fossil record can also be of the activity of an organism such as footprints, burrows and faeces. Some major way of fossil formation are,


  • Permineralization occurs when dissolved minerals carried by ground water fill the cellular spaces of plants and animals. The dissolved minerals crystalise and produce rocks in the shape of the animal or plant. This is the most common type of fossil preservation and examples include teeth, bones, shells and wood.
  • Natural casts form when flowing water removes all of the original bone or tissue, leaving just an impression in sediment. Minerals fill in the mold, recreating the original shape of the organism. these are commonly marine invertebrates like shells.
  • Amber preserved are organisms that become trapped in tree resin that hardens into amber after the tree gets buried underground. Examples include insects, pollen, lizards and frogs.
  • Trace fossils record the activity of an organism. They include nests, burrows, imprints of leaves, footprints and poo.
  • Preserved remains record intact remains of animals, often including preserved skin, muscle, bone, hair and internal organs. Fossils form when an entire organism becomes encased in material such as ice or volcanic ash or buried in peat bogs. This is a much rarer form of preservation than the other forms above. Examples are mammoths.
Identification of fossil
  • Whole body or the part of an organism is trapped on sedimentary rock which can be found, identified and the age of fossil can be calculated.
  • The buried parts of organism sometime come out on erosion, landslide etc and can observed easily
  • Sometime hard bone, teeth of animal and hard wood of plant are found inside rock and easily identified

Importance of fossil

  • Fossil provide fossil fuel
  • Study of evolution of life is made easier
  • Relation between time and organism is determined
  • Age of fossil and hence age of rock is determined
  • Study of ancient organism is easier


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