1. Evolution of Multi-cellular Life

2. Precambrian Time
Almost 90% of the Earth’s history fits in Precambrian Time
Simple anaerobic life appear
Oxygen appeared after photosynthetic organisms appeared.
Aerobic life appeared.
Simple multi-cellular life appeared.

3. Paleozoic Era
Begins with simple invertebrates; ends with fish, amphibians, reptiles and seedless plants and a mass extinction
Cambrian Period
Ordovician and Silurian Periods
Devonian Period
Carboniferous and Permian Periods

4. Cambrian Period 1st examples of shells and outer skeletons
1st example of many animals evolved
Invertebrates – jellyfish, worms and sponges
“Cambrian Explosion” – rapid diversification of life forms

5. Ordovician and Silurian Periods
Ancestors of squid, octopus and lobster appeared.
The first animals moved onto land – arthropods similar to modern insects.
1st vertebrate animals – jawless fish- appeared.
Low growing plants appeared in wet areas.

6. Devonian Period Plants were able to move into drier areas.
Invertebrates were more numerous in the ocean
Bony fishes and sharks appeared during this period.
Vertebrates began to leave the ocean, but insects were more numerous on land.

7. Carboniferous and Permian Periods
Reptiles appeared.
Insects continued to evolved; included winged forms.
Giant ferns formed large forests.

8. Mesozoic Era
Marked by the appearance of flowering plants and increasing dominance of reptiles in the form of dinosaurs
Triassic Period
Jurassic Period
Cretaceous Period

9. Triassic Period
Fish, insects, reptiles and cone-bearing plants survived the extinction.
1st dinosaurs appeared 225 million years ago.
Small mammals – size of a mouse – appeared during this time.

10. Jurassic Period
Large plant-eating dinosaurs were the dominant life-form.
The 1st bird evolved from dinosaurs during this period.

11. Cretaceous Period Meat-eating dinosaurs dominated the land.
Flying reptiles appeared.
Flowering plants appeared

12. Cenozoic Era
Marked the rise of the mammals after the dinosaurs became extinct
Tertiary Period
Quaternary Period

13. Tertiary Period
Warm mild weather encouraged the growth of large, herbivorous animals.
Whales and dolphins evolved.

14. Quaternary Period The current period of time
Began with the advance of the glaciers
Mammals are the dominant species of this time.