num_pages: 80
description: Details the evolutionary and geologic changes that occurred during the Mesozoic era, including the presence of dinosaurs and the breakup of Pangaea into separate landmasses.
language: English
title: When Dinosaurs Ruled
titlecomplete: When Dinosaurs Ruled (Prehistoric North America)
genres: Nonfiction
ratings_count: 6
publisher: Heinemann-Raintree