This is the second book in the Kittysaurus series. It is the story of 2 children, Clara and Zeke, who want to be paleontologists. In this book, they are trying to figure out how to hatch the Kittysaurus egg they found in the first book. They travel back to the zanyzoic time to see if they can spy on Kittysaurus to see how she hatches her egg. They meet up with Cynodonts (the first mammals) who have some secrets about time-traveling of their own. Will they find out how to hatch the egg? Will Miles Vulture find out about the time-traveling? Will they get eaten by Kittysaurus?

This book is a children's adventure story, and while it contains some relevant facts, it is a fantasy adventure series. Clara and Zeke take risks that children of that age would not in real life. These two are quite smart and are able to outsmart the adults in many cases that would entertain the reader. There is a bit of an antagonistic relationship at times, but I liked that they both realized that they wanted to be together. I did not like this book as much as the first one, perhaps it was the ending. It ends in a cliff-hanger, which is not the problem, but that it just ends rather quickly. The other thing that I wish the book had were illustrations. Considering the age group this book is aimed it, illustrations would add a lot to the story and help to maintain interest.