Time Scales

Question 1

Number of time measurement systems & acronym

Answer 1

• MYA (millions of years ago)

Question 2

Major geological events using a timescale relating to rocks

Answer 2

• Earth formed – 4700 mya
• Oldest rocks – 4300 mya
• Oldest life – bacteria 3800 mya
• First vertebrates – 500 mya
• First mammals – 200 mya
• First primates – 65 mya
• First Homo – 2 mya

Question 3

Eon

Answer 3

Several hundred millions of years

Question 4

Era

Answer 4

Tens to hundreds of millions of years

Question 5

Period

Answer 5

Millions of years to tens of millions of years

Question 6

Epoch

Answer 6

Thousands of years to millions of years