This book lacked something. It seemed dully presented, even though the facts were interesting. Maybe it could have been organized better or differently. I think a large part of my reaction to the book was due to the pictures, which I felt that, nice though they were, lacked dynamism. On some pages the pictures needed have been more detailed, or there should have been sidebars, for additional information, to match or illustrate what was in the text. For example, on page 17 the text mentioned More...

This book is another book by the same author of Pterosaurs: Rulers of the Skies in the Dinosaur Age.
This book would also be difficult for third graders.
It talks about the dinosaurs that lived in the ocean. It has when they lived, where they lived, various types, sizes and body composition, lifestyle and habits, people who found their fossils, where you can go in the United States and Canada to see fossils.
It also has an index.