{Paleontology ˌpālēənˈtäləjē/ noun noun: palaeontology; noun: paleontology the branch of science concerned with fossil animals and plants.
What is a fossil? The preserved remains of living things or traces of living things. These are often found in sedimentary rock.
How do fossils form? Organism dies and sinks to the bottom. Sediments cover the organism. The sediments become rock, preserving parts of the organism.
Millions of years pass…. Only the hard parts of the organisms may fossilize. Soft parts decay too quickly. Geologic events like uplift, weathering, and erosion bring the fossil closer to the surface. Fossil is exposed at the surface.
What are the types of fossils? molds/casts trace petrified impressions carbon films
What is a trace fossil? Traces of an organism’s activities burrows nests poop tracks trails footprints
mold An imprint left behind when an organism is covered by sediments before it decays
cast Water and sediment fills a mold and makes a copy of an organism
mold cast
Mineralization or Petrification Petrified fossils are created when water containing minerals seeps into the open spaces found within an organism. After millions of years, these minerals crystallize and form an almost glass-like copy of the organism.
Impression Commonly made in clay or silt, trace fossils will fall into this category. Plant leaves are commonly found as impressions.
Carbon Films All organisms are made of carbon. Sometimes, when an organism rapidly decays, the carbon in their bodies remains. This leaves a perfect “shadow” of the creature in carbon.