- By carefully analyzing landforms, rocks and fossils - A fossil of an animal that was around on earth at a particular time in history

The history of the earth from its formation to the present. The earth’s history maybe divided into several major time periods, called ERAS. - A time of major sediment deposition and earth movement

“Before history” 4, 600 m.y. Lasted 4 b.y.

Birth of Earth 4.6 b.y

- Moon forms 4.5 b.y. when a large asteroid hits earth causing pieces to fly out into space

- Earth’s surface solidifies 4.4 b.y. and cools - Over time the earth’s core gets hot and starts the process of “Plate Tectonics”

- Gases released from volcanoes condenses into clouds and it rains on earth. - Rainwater created the oceans (formed 4.4 – 4.2 b.y)

- Early atmosphere forms 4.0 b.y. (no living organisms on land)

- Formation of the Canadian Shield m above sea level - About 1.2 b.y. continents assembled into“Rodinia”

- First life 4.0 b.y. in the oceans

- First Cyanobacteria - Stromatolites (living reefs) released O2 into the atmosphere

- Oxygenated atmosphere forms 2.4 b.y. - 1 st single celled organisms (algae) in water environment

- 1 st mutli-celled organisms - Jellies 580 m.y - Primitive life forms

“old”“life” 570 m.y. 325 m.y.

- Age of fish and amphibians - 1 st insects - Large swamps (coal formed from this vegetation)

- 1 st plants & animals appear on land

- Arthropods 535 m.y.(80% of all living species - means “jointed legs”)

- Trilobites 525 m.y. - Cambrian explosion (appearance of many new species)

- Echinoderms 525 m.y.

- Ordovician m.y.a - True land plants arise, leafless at first 470 m.y.

- Jawed fish 425 m.y.

- Horseshoe crabs 400 m.y.(1 st to leave the sea)

- Amphibians 370 m.y.

- Carnifers 315 m.y.

- Reptiles 310 m.y. - Scales and skin protect reptiles. Spikes serve as camouflage and defence

- Great change rocks the earth; continents go dry, results in mass extiniction 250 m.y.

- N.A covered by shallow seas - Appalachians formed (300 million years ago)

“middle” “life” 245 m.y. 180 m.y.

- Age of reptiles – “dinosaurs”

be.com/watch? v=OfHdYcKDh6 A&feature=rela ted “Planet Dinosaur”

- 1 st flowering plants - 1 st birds & mammals (warm-blooded)

- 1 st birds 150 m.y.

- Cretaceous 146 – 65 m.y.a. - Ants 130 m.y Co-evolution entwines insects and birds with plants forever

- - Formation of the rocky mountains begin - - Innuition mountains formed - - Shallow seas in the interior of N. America at various times

- - Formation of the rocky mountains begin - - Innuition mountains formed - - Shallow seas in the interior of N. America at various times

“recent” “life” 66 m.y

- Modern forms of life evolve - Age of mammals - Human being develop

- Primates evolve in jungle 55 m.y - Tarsiers believed to be linking links to a branch of early primates who evolved in the rainforests 50 m.y.

- Whales 50 m.y. - Long-bodied land mammals with hoofed feet turned into marine creatures

- Elephants 50 m.y. - Last of the great mega-herbivores that once roamed the earth on all continents except Antarctica

- Sea Lions 20 m.y.

Quaternary 1.8 mya - today - Homo-erectus 2 my –

Ice Age 100, 000 – 10, 000 yrs

Modern Humans 0.2 m.y

- Ice sheets cover much of N.A - Formation of rocky mountains complete - Coast mountains form and complete - Continents take their present shape