Hobbies And Interests
Significance
Fossils help teach us how long life has existed on earth and what earlier periods in our planet's history were like. Fossils provide a picture of many extinct species of plants and animals. By studying fossils, scientists learn how, when and where plants and animals lived in the past, giving clues to the evolution of species and the types of environment in which they lived.
Fossil Formation
Fossils can form in a variety of ways. An insect or small organism can be preserved in amber. Freezing or rapid drying can promote preservation of tissue in fossilized form. The La Brea Tar Pits in Southern California, where thousands of fossils have been found, demonstrate the preservative qualities of asphalt. Plant leaves are commonly fossilized through carbonization, which occurs when, after decomposition, carbon remains and makes an impression on surrounding rock. The most common type of fossilization is permineralization, in which minerals replace the decomposed cellular space and crystallize.
Identification
Fossils are divided into either body fossils or trace fossils. Body fossils show us what a plant or animal looked like. Shells, bones and leaves are types of body fossils. Trace fossils teach us about the activity of an organism. Trace fossils include footprints, nests, trackways and burrows. This type of fossil gives us an idea of how animals lived.