Presentation on theme: "The remains or evidence of a"— Presentation transcript:
1The remains or evidence of a FossilsThe remains or evidence of aliving thing
2Fossils: Remains, Imprints, Traces, or Evidence of Once Living Organisms. Tells us what , where, when, how organisms lived.Tells us the history of life on earth.Tells us about climates and environments of the past.
3Conditions Necessary to Create Fossils. Organism quickly buried to avoid decay.Hard parts which are less likely to decay.Usually occur in Sedimentary rock.
4Types of Fossils Carbonaceous Films Mold & Cast Trace Fossils Petrified RemainsOriginal Remains
5Carbonaceous Films Like a picture of the organism. Thin layer of carbon often left behind forming image.
6Mold and CastBuried hard parts in rock dissolve or decay leaving a MOLD (empty space in rock).Mold later fills with sediments that harden forming a CAST (filled in mold).
7Trace Fossil Evidence of animal activity. Examples: Footprints Worm holesBurrows
8Trace FossilsMarks or evidence of animals but show no part of the animalEx: footprints, droppings, burrows
9Petrified Remains Hard and rock like Original material replaced by mineralsWater flows through removing material and carrying minerals that crystallize in their placeMost bones found are petrified.
10Original Remains Actual parts of organism found Examples: Insect in amberAnimal frozenAnimal trapped intar
11Preservation Freezing Amber: when sap fossilizes with trapped organismsTar Pits: trap animals and preserve them
12Fossil Interpretation Fossils are arranged according to age, so they show a progression of developmentFossils indicate past surface conditionsFossils give evidence of past climatesFossils tell appearance and activity of plants and animals
13Index Fossils From species that Existed for a short period of timeWere abundantWere wide spreadUsed to determine the age of rock layers that contain them.Rock layers that contain the same index fossil are thought to be about the same age.