Name the time in Earth's history: Clue #1: 251 million years ago Clue #2: Age of Reptiles Clue #3 ended by asteroid colliding with Earth
What is the Mesozoic era?
Name the time in Earth's history: Clue #1: 65 million years ago up until today Clue #2: fossils are in the top layer
What is the Cenozoic era?
This states that the oldest layers of rock are at the bottom and that layers get newer as you reach the top?
What is the Law of Superposition
Name the time in Earth's history: Clue #1: Humans first appeared
What is the age of mammals?
Cenozoic Era
Earth is approximately how old?
4.6 billion years
The law of croscutting states that the diagonal layers that cut through sedimentary rock are __________ than the horizontal layers that they cut through
What is younger?
The first trace of life on earth can be traced back to how many billions of years ago?
3.8 billion years ago.
What is it called when a layer of sedimentary rock is missing from the fossil record?
What is an uncomformity?
What are the characteristics that make a good index fossil?
only found in one layer/found in many different areas