GLGY 209 Lecture Notes - Lecture 23: Trace Fossil, Trilobite, Arthropod
3 May 2019
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Document Summary
Represent fragments of the original body of the organism (hard parts and/or soft parts which in some cases can be preserved) Preserve a trail of a certain activity (eg. walking, feeding, flying) Pigments interact with substance in the surrounding environment to form stable substances. Chemical analysis must be used to identify these as well as time of evolution. If they consists of minerals, they can be preserved very well. But at some point, see in the fossil record that when they occur, they are already so complex that they indicate a long period of evolution before. Microorganisms of the same group before the fossilized organism might not have had protective structures. However, chemical analysis can allow us to identify the existence of these pre-historic organisms. In most cases (microorganisms), palaeontologists do most of the study. In old rocks, 300-500 million years old.
