Science Focus Topic 8 Notes: Fossils | Print |
Fossils are preserved impressions in rock that tell us when, where, and how living organisms lived and behaved millions of years ago.

Types of Fossils

Remains of dead plants and animals that have been protected from scavengers can become fossilized in a number of ways:
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petrified (rock-like) fossils preserve the bones of dead animals by using silica
- an outline or impression from the carbon residue on rock surfaces can provide a
carbonaceous film
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original remains may be preserved in tar, amber or peat bogs
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trace fossils are evidence of animal activity, like worm holes, footprints, and burrows

Dinosaur Finds

(Dinosaur Provincial Park is a world UNESCO Heritage site, where over 36 species of Dinosaur have be found - nearby, Burgess Shale in B.C. is also renowned because of the rich deposits of fossilized marine animal soft-body parts)
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Trilobites date back before the dinosaurs roamed the Earth
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Ammonites are common fossils found in Alberta
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Oviraptor (when a clutch of eggs were found with a fossil of this dinosaur, it was thought it was a scavenger, but further evidence indicates it was likely an overprotective parent)
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Gigantosaurus, found in Argentina is heavier than Tyrannosaurus Rex, a carnivore.
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Seismosaurus, a huge plant eater, was found in Mexico (its tail could move faster than the speed of sound)
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Bambiraptor, a dinosaur, found by a 14 year old boy in Glacier National Park, Montana, may help to provide the link between birds and dinosaurs

Fossil Mould and Cast Formation

An animal dies in mud and gets covered by more sediment. The body dissolves, leaving a mould, which is then filled with more sediment and hardens into rock, making a cast of the original animal.