• Taphonomy
• Taphos = burial/death, nomos = laws
• Transition from the biosphere to the lithosphere
What are fossils?
• Definition: The remains or trace of organisms preserved from the geologic
past........
• Antiquity
• Fossils = sedimentary particles or fabric
How do fossils form?
• a very small fraction of organisms that have lived on Earth represented
as fossils......Why?
Taphonomic Loss
• Taphonomic processes - food webs, chemical cycling, decay, scavengers,
currents, waves, etc
• Taphonomic Loss = Bias in the fossil record……….
• Taphonomic signature = gain of environmental information
– Behrensmeyer and Kidwell (1985)
Bias in the Fossil Record
• With the people next to you discuss the following.
• Which realm has the more complete fossil record
– Terrestrial or marine? Why?
Rules of Taphonomy
• The probability of preservation is enhanced by
1. Hard parts
2. Rapid burial - removal from TAZ
Types of preservation...
Typical Fossils
• Unaltered Skeleton
• Petrification/Permineralization
- pores filled with silica
- light material becomes much heavier
• replacement (pyrite and quartz)
- atom for atom replacement
• molds and casts
- shell dissolved away - mold
- space filled with sediment -cast
• Carbonization
- organics in plant preserved as carbon film
- similar process to forming coal
* exceptional preservation
- most of organism preserved - including soft parts
1) freezing
2) mummification
3) amber
Exceptional Preservation of Communities
= Lagerstätten (“mother lode”)
- Burgess Shale (Cambrian)
- Mazon Creek (Carboniferous)