Kristen Rajczak Nelson 
Amphibians [PDF ebook] 

All amphibians spend part of their life on land and part in the water. What part and for how long varies between species. In this engaging and colorful text, readers learn the main characteristics that make an animal part of the amphibian group and the many unique adaptations that can occur within the bounds of that characteristic. With main content supporting the Next Generation Science Standards core ideas of adaptation, ecosystems, and biodiversity, this book is a great introduction to one of the many animal groups on Earth.