A rapid increase in life forms at the beginning of the Paleozoic Era.
What is the Cambrian Explosion?
The Mesozoic is also known as the age of *blank*.
What is the Age of Reptiles?
The two Eons included in Precambrian time.
What is Archean and Proterozoic?
The study of life that existed in prehistoric times.
What is Paleontology?
The first mass extinction.
What is the Ordovician extinction?
The supercontinent that broke apart at the end of the Triassic Period.
What is Pangaea?
The Archean Eon began with the formation of Earth's first *blank*.
What are rocks?
Is formed when minerals fill a mold an organism has left behind in hardened sediment.
What is a cast?
A period in the Paleozoic era that had an ice age and the beginning of the great dying extinction event.
What is the Permian Period?
The periods of the Mesozoic Era in the order they occurred.
What are the Triassic, Jurassic, and Cretaceous periods?
The Archean and Proterozoic eons cover around *blank* years of earth's history.
What is 4 billion?
A mountain range that began in the Ordovician period.
What is the Appalachian mountains?
The area where the asteroid that struck the Earth at the end of the cretaceous period.
What is the Yucatan Peninsula?
An exposed area of a craton is called *blank*.
What is a shield?
An example of replaced remains, where organic material is gradually replaced by rock-forming minerals into a hard copy of the original.
What is petrified wood?
The approximate length of the Paleozoic Era.
What is 543 million years? (500-550)
This group of seed plant was very dominant in the Mesozoic Era.
What is a Conifer?
Layered mats of Cyanobacteria and trapped sediments create these layered dome or column-shaped fossils that make up the greatest number of Precambrian fossils.
What are Stromatolites?