GEOL 303 Lecture 6: Geology 303 Lecture 6
Document Summary
Two major division in the geologic time scale. Life existed but were simple, single form organisms, did not evolve. Organisms did not rely on photosynthesis but relies on oxygen. Older the rock is, the more difficult it is to reconstruct the history. 543 million years ago was the explosion of life on earth. 2 of those form the boundaries between paleozoic and mesozoic (252 million years ago), and the mesozoic and cenozoic (65 million years ago) Name comes from cretaceous (k) and tertiary (t) One object was very large that collided with our planet, and threw material into space, creating the moon. Trilobite - genera broken down into numerous different species. Paleozoic is known as the age of the fishes. Sharks survived both mass extinctions, which is unusual. Amphibians evolved into reptiles, capable of living on land. Plants started growing on the periphery of the planet because they needed water.
