Fifth Grade
Worksheets
The Mesozoic Era
When we talk about time, we have many words to use to talk about different times in our lives. Summers, mornings, months, afternoons, years, and weekends are just a few of them. When you think back over your lifetime, you may remember blocks of time like the summer you were five or your second grade school year.
When scientists talk about time, they need words to name the exact time they are talking about, too. Earth was formed about 4.6 billion years ago. That's the same as 4,600 million years. That's a very big chunk of time! So, those millions of years have been divided up into large chunks that have something in common. Then names have been given to each large chunk of Earth's history.
The first dinosaurs lived about 225 million years ago. This was in the Mesozoic era, also called the Age of Dinosaurs. The Mesozoic is divided into smaller chunks of time.
