This is the longest unit of recorded time and lasted over 4 billion years.
What is Pre-Cambrian Time?
100
The Paleozoic Era consists of this number of time periods.
What is 6?
100
These Mesozoic organisms ruled the earth for over 60 million years and were predecessors to many reptiles species still in existence.
What are Dinosaurs?
100
The time period in which we currently live.
What is the Quaternary Period?
200
The earliest forms of life on Earth lived here.
What is the ocean?
200
This time period is highlighted by an "explosion" of invertebrate life forms in the oceans.
What is the Cambrian Period?
200
Dinosaurs Dominate during this Mesozoic time period as flying reptiles and snakes emerge on land.
What is the Jurassic Period?
200
This Cenozoic time period is known as the "Age of Mammals".
What is the Tertiary Period?
200
An organism without a backbone.
What is an Invertebrate?
300
These Pre-cambrian marine organisms were responsible for producing huge amounts of Oxygen.
What are Stomatolites?
300
This time period lasted approximately 41 million years and is noted for the largest mass extinction in the earth's history.
What is the Permian Period?
300
This specific time period is called "The Age of the Reptiles".
What is the Triassic Period?
300
This mountain range was formed during he Tertiary Period when the Eurasian and African continents collided.
What is the Himalaya's?
300
An organism that can live in both aquatic and land environments.
What is an Amphibian?
400
Early in Earth's development, this planet collided with earth breaking off debris which eventually became its moon.
What is Thea?
400
During this time period earth was covered with massive wetlands and swamps which eventually became buried and led to the formation of "Coal Forests" and crude oil.
What is the Carboniferous Period?
400
Towards the end of this Mesozoic time period, a mass extinction occurred eliminating over half of all life forms including dinosaurs.
What is the Cretaceous Period?
400
The Theory presented by Alfred Wegener explaining the movement of the continents to their present locations from used to be Pangaea.
What is Continental Drift?
400
A gradual change in living organisms over a long period of time.
What is Evolution (or Adaptation)?
500
During a meteor shower lasting 20 million years, these 3 essential elements theoretically were deposited on to earth leading eventually to living organisms.
What is Water, Minerals, and Amino Acids?
500
These are the names of the 6 time periods within the Paleozoic Era in order from most distant to most recent.
What are the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian time periods?
500
When the reign of Dinosaurs ended, their "Niche" was filled by these newly evolved organisms.
What are Mammals?
500
Two important events which allowed grass-eating mammals, flowering plants, and insects to thrive.
What is a stabilized atmosphere, 24-hour days, and a warm climate?
500
Most fossils are formed when organisms die are are buried in this type of earth crust.