Chapter 12
Earth and Life History
There was a time when Earth had a warm, tropical climate
all over. Dinosaurs roamed Earth, and giant plants called
cycads grew everywhere. Earth’s land masses formed one
giant continent. This might sound like science fiction, but it
is actually a simple description of what geologists call the
Mesozoic era in Earth’s history. How do geologists know what
Earth and its life forms were like millions of years ago?
Explore this chapter to find out!
- What do rock layers tell us about Earth’s
history? - How is Earth’s surface like a giant jigsaw
puzzle? - How long ago did dinosaurs live on Earth, and
what happened to them?