ESCI 402 6 Biostratigraphy

  1. Fossil
    any remains, impression, or trace of a living thing of a former geologic age

    Tell us about past environment – can be used to date rocks
  2. Porifera
    – sponges, spicules w/ distinctive spikes
  3. Protezoa
    single cell eukanyote
  4. Bryazoa
  5. Cridaria
    Corals, jellyfish, have radial symmetry
  6. Brachiopoda
    lamp shells, left/right symmetry, shells not symm to each other
  7. Mollusca
    clams, gastropods (slugs,snails) cephalopods
  8. Arthropoda
    • Insects, crustaceans,
    • Trilobites (early cambrian to late permian)
    • segmented exoskeleton, bilateral symm.
  9. Echindermata
    crinoids, sea urchins, sea star - 5 way radial symmetry
  10. Cordata
    notochord, aka nerve cord, bilateral symmetry
  11. Required factors for fossilization
    fast complete burial, anaerobic environment
  12. Unaltered Remains
    encased in amber, bog people (anaerobiv env.), frozen
  13. Replacement
    original biological tissues are replaced by new mineral
  14. Permineralization
    (petrified wood) – fluids fx. dissolved quartz may precipitate though wood, filling in voids
  15. Carbonization
    thin carbon film left behind after compression, can record detailed microstructure
  16. Mold & Cast
    • internal and external casts- tracks, burrows, tunnels, footprints (trace) fossilized dung
    • (copralites)
Card Set
ESCI 402 6 Biostratigraphy
Biostratigraphy and fossils