1. Geologic Eras

2. Earth’s Birthday The Earth is very old, 4.6 billion years old!
Humans have been around for a tiny slice of that time

3. If the earth’s history was compressed into a 24 hour day…

4. Another cool fact
A book with one page for every year of earth’s history would be 145 miles long and take you 17,500 years to read.

5. The earth can be divided into four main geologic eras
The earth can be divided into four main geologic eras. An era is a span of time in the earth’s history where significant geologic events occurred.

6. The four eras include:
Precambrian
Paleozoic
Mesozoic
Cenozoic

8. Precambrian- “The oldest and longest”
Began 4.6 billion years ago and lasted for 4 billion years
Accounts for 87% of the earth’s history
The Bedrock of Canada was formed
Only part of Canada that existed was the Canadian Shield
By the end of this era the first complex organisms had appeared (eg bacteria, 4 billion yrs ago, algae, 3 billion yrs ago)

9. Stromatolites (The oldest known fossils on earth)
The section of river near the Champlain Bridge has one of the best known displays of fossil stromatolites in the country – and certainly in any urban area. At low water periods at the end of dry summers and early fall large slabs of sedimentary rock appear along the river to expose the stromatolites and other ancient creatures. More stromatolites are visible in the transitway walls from the pedestrian bridge at the endof Roosevelt Avenue in Westboro.

11. Palezoic
The Paleozoic had two of the most important events in the history of animal life. At its beginning, multicelled animals underwent a dramatic “Explosion” in diversity, and almost all living animals at the time appeared within a few millions of years.
At the other end of the Paleozoic, the largest mass extinction in history wiped out approximately 90% of all marine animal species. The causes of both these events are still not fully understood

12. Paleozoic- “Age of the Fish/Amphibians”
Last 345 million years
North America was located near the equator
Shallow seas covered the now, Interior Plains of Canada
Swamps produced coal and natural gas
Appalachian mountains were formed
Fish, insects first appeared in the beginning of this era and amphibians were found at the end of the era
Simple plants appear on land

14. Mesozoic- “Age of the Dinosaur”
Lasted 180 million years
Rocky Mountains were formed
Seas covered large parts of North America
Dinosaurs and other reptiles roamed through huge swamps and forests
First swamp plants appear
First birds and mammals appear
Innuitian mountains are formed
Mass Extinction marks the end of the Mesozoic era

15. fyi
Canada was home of the first ever found dinosaur. They called it Albertasaurus because it was found in the badlands of Alberta.

16. fyi
Dinosaurs are not extinct. Technically. Based on features of the skeleton, most people studying dinosaurs consider birds to be dinosaurs. This shocking realization makes even the smallest hummingbird a legitimate dinosaur. So rather than refer to "dinosaurs" and birds as separate groups, it is best to refer to the traditional, extinct animals as "nonavian dinosaurs" and birds as, birds, or "avian dinosaurs.”
It is incorrect to say that dinosaurs are extinct, because they have left living descendants in the form of cockatoos, cassowaries, and their pals

17. fyi The “raptors” (Dromaeosauridae)
According to current thinking, birds are hypothesized to have shared a common ancestor with the dromaeosaurs sometime in the Jurassic period; Dromaeosauridae is thus termed the sister group of the clade Aves (which includes all birds).

19. Cenozoic- “Age of Humans”
Current geologic era
Ice sheets covered much of North America
“Ice Age”=Glaciers
Formation of Rocky Mountains continues
Human beings develop
Mammal forms of life evolve into species we know today

22. Clip from “Walking with Beasts” BBC Documentary