Geologic Time Line Organisms

Precambrian TimeBefore 570 mybp

• Bacteria• Algae• Worms?

Paleozoic Era570-225 Million Years Before Present

Common Organisms• Jellyfish• Sponges• Corals• Worms• Crinoids• Brachiopods• Trilobites

Corals

Trilobites

More Trilobites

Crinoids

Brachiopods

Horseshoe Crabs

Mesozoic Era – Age of Dinosaurs225-65 Million Years Before Present

Common Organisms

• Ammonites – Dominated the Mesozoic seas• Dinosaurs – Dominated the Land• Archaeopterix – First bird

Ammonites

Archaeopteryx

Cenozoic Era – Age of Mammals65 Million Years Before Present to the Present

Australopithecus afarensis 3.85-2.95 million years ago

• Australopithecus afarensis is an extinct hominid that lived between 3.85 and 2.95 million years ago.[1] A. afarensis was slenderly built, like the younger Australopithecus africanus. It is thought that A. afarensis was more closely related to the genus Homo (which includes the modern human species Homo sapiens), whether as a direct ancestor or a close relative of an unknown ancestor, than any other known primate from the same time.

• The most famous fossil is the partial skeleton named Lucy (3.2 million years old) found by Donald Johanson and colleagues.