FossilsCommonly Preserved:Rarely PreservedTypes of FossilsPseudofossilsSlide 6A PseudofossilNatural or Sculpture?Johannes Beringer’s “Fossils”Beringer’s BookWhere Fossils OccurGood Index FossilsCorrelationPowerPoint PresentationSlide 15Slide 16Slide 17Slide 18Slide 19The Geologic Time ScaleFossilsRemains of Ancient Plants And Animals, Evidence of LifeCommonly Preserved:Hard Parts of Organisms:•Bones •Shells •Hard Parts of Insects •Woody MaterialRarely PreservedSoft or Easily Decayed Parts of Organisms:•Internal Organs •Skin •Hair •FeathersTypes of Fossils•Original Material •Casts & Molds •Replacement (Petrified Wood) •Carbonized Films (Leaves) •Footprints, Tracks, Etc. –“Trace Fossils” – Our only preserved record of behavior of fossil organismsPseudofossilsLook Like Fossils But Aren't•Dendrites •ConcretionsPseudofossilsA PseudofossilNatural or Sculpture?Johannes Beringer’s “Fossils”Beringer’s BookWhere Fossils OccurAlmost Exclusively in Sedimentary Rocks•Heat of Melting or Metamorphism Would Destroy Almost Every Type of Fossil •Rare Exceptions: –Some Fossils in Low-grade Metamorphic Rocks–Trees Buried by Lava Flow To Be Preserved, Organisms Have to Be:•Buried Rapidly After Death •Preserved From DecayGood Index Fossils•Abundant •Widely-distributed (Global Preferred) •Short-lived or Rapidly ChangingCorrelationCorrelationThe Geologic Time ScaleQuaternary Latin, “fourth” 1822Tertiary Latin, “third” 1760Cretaceous Latin creta, “chalk” 1822Jurassic Jura Mountains, Switzerland 1795Triassic Latin, “three-fold” 1834Permian Perm, Russia 1841Carboniferous Carbon-bearing 1822Devonian Devonshire, England 1840Silurian Silures, a pre-Roman tribe 1835Ordovician Ordovi ces, a pre-Roman tribe 1879Cambrian Latin Cambria, “Wales”