Paleontology “How to become a fossil without really trying.”

Fossils Remains or traces of ancient life Remains or traces of ancient life Includes: Includes: Bones Bones Teeth Teeth Shells Shells Tracks, trails, footprints Tracks, trails, footprints Rarely – soft tissues Rarely – soft tissues

How does an organism become a fossil? Rapid burial is essential Rapid burial is essential Protection from scavengers, decomposers, physical deterioration Protection from scavengers, decomposers, physical deterioration

What helps? Hard or durable tissues, such as: Hard or durable tissues, such as: Shells Shells Bones Bones Teeth Teeth Exoskeleton Exoskeleton Woody tissue Woody tissue

What conditions favor preservation? Rapid burial is most likely in ocean Rapid burial is most likely in ocean Sea creatures with shells are fairly easy to preserve Sea creatures with shells are fairly easy to preserve Conclusion: Marine organisms with hard parts are most likely to become fossils Conclusion: Marine organisms with hard parts are most likely to become fossils Extension: Other organisms are less easy to preserve. Extension: Other organisms are less easy to preserve. Further extension: Fossil record is biased. Further extension: Fossil record is biased.

Types of Preservation Original shell, bone or teeth Original shell, bone or teeth Altered hard tissues (replaced by different mineral material) Altered hard tissues (replaced by different mineral material) Molds and Casts Molds and Casts Trace fossils: burrows, tracks, trails Trace fossils: burrows, tracks, trails Soft Tissues Soft Tissues Carbon film Carbon film Amber Amber Mummified Mummified Frozen Frozen

Original Hard Material

Altered Hard Tissue

Molds and Casts

Carbon Film

Amber

Impression and Carbon film

Carbon Film - Plants

Microfossils

Utility of Fossils History of Life on Earth History of Life on Earth Evolution – appearances of new species Evolution – appearances of new species Extinction – disappearances of species Extinction – disappearances of species Framework for other events in Earth’s History Framework for other events in Earth’s History Guide in exploring for fossil fuels Guide in exploring for fossil fuels