geology final exam interlude E & Chapter 10 cards

fossils

the preserved remains or traces of ancient organisms, often found in sedimentary rocks, providing insights into past life and environments.

Requirements of fossilization

• Must be Dead (there are NO living fossils!) 

• Must have hard parts: bones, teeth, shells, etc. 

• Rapid burial: to prevent being eaten by scavengers or others. 

• Remain undisturbed: not be exposed or dug up by erosion processes or avengers.

Methods of fossilization

Various processes, including permineralization, cast and mold formation, and amber preservation, that lead to the preservation of organic remains.

Types of fossils

• Preserved remains 

• Trace fossil 

• Mold fossil 

• Cast fossil 

• Petrified fossil 

• Carbon film

Original remains

Fossils that include the actual tissue of the organism, preserved in its original form, such as insects in amber or frozen mammoths.

Replacement

A form of fossilization where the original organic material is replaced with minerals, preserving the structure of the organism.

Carbonization

only a thin organic film remains of organism, usually preserved in shale; remainder of flesh & bone has decayed away.

Permineralization

A process of fossilization where minerals fill the spaces within the organic tissues, preserving the internal structure of the organism.

Recrystallization

A fossilization process in which original minerals of a shell or skeletal structure dissolve and re-form into new crystals, often making them more stable.

Trace fossils

Fossilized evidence of an organism's activity, such as footprints, burrows, or feces, rather than the organism itself.

Casts & Molds

external and internal impressions of the organism; most common type of fossil

Coprolites (dung)

fossilized feces that provide insight into an animal's diet and behavior.