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Unlock the wild world of mammals—now in paperback!


Fuzzy, scaly, clawed, and finned—mammals can be found in the depths of the ocean and the heights of the mountains. Mammals Unlocked and the bilingual edition, Mammals Unlocked / Mamíferos descubiertos, illuminate the vastness of the mammal world in a simple, interactive question-and-answer format.


These first paperback editions of the Open Earth / Tierra Abierta series are a dynamic introduction to class Mammalia, perfect for any kid who’s fascinated by mammals big and small. Discover all the facts you need in order to wow your friends, impress your teachers, and dazzle your dog! Mammals Unlocked is sure to stimulate and challenge even the most knowledgeable animal lover.

Book details 

English Paperback (ISBN 978-1-958629-13-0)

Bilingual Paperback (ISBN 978-1-958629-15-4)

Age range 
8 - 12 years 

Grade range
3rd - 7th Grade



Get the book in Hardcover

Available now!


"★★★★★ This resource, with its engaging questions and introduction to diverse mammalian members followed by its clearly explained answers, provides an arousing and intriguing introduction to basic science and an awareness of the adaptations nature provides for the survival of the species."

—Manhattan Book Review

"Find all of what you didn’t know about mammals in this engaging and thought provoking new series. The chapters take you around the world visiting many of the over 6,400 mammal species... Mammals Unlocked  is perfect for upper elementary and beyond. The level of curiosity is enhanced with each fact unlocked. A great gift for this upcoming holiday season."

—Always In the Middle, Middle Grade Book Reviews

Praise for Mammals Unlocked



Dia L. Michels is an award-winning science and parenting writer who has authored or edited over a dozen books for both children and adults. While her topics include science and math books for middle grade students, her passion is promoting attachment parenting and supporting breastfeeding. A popular speaker, she lectures frequently at conferences, universities, libraries, and schools around the country. The mother of three grown children, she lives in the Capitol Hill neighborhood of Washington, D.C., with five cats and a dog. She can be reached at

MEET THE Illustrator


Bonnie Hofkin's first picture books and early readers, growing up in the home of a physician, were medical journals and anatomy texts. With her interest in the human body thus igniting a lifelong love of art, she first obtained a BA in commercial illustration, followed by a master's degree in medical illustration. Subsequently, she embarked on a 40+ year career as a freelance illustrator. Still going strong, her unique style, in which an eye for accuracy and visual appeal is combined with a classical look reminiscent of the great Renaissance masters, is instantly recognizable.

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