An engaging introduction to an animal family that's found its niche in the slow lane.There are six types of sloths living today, Shreeve writes, but many more used to roam the Americas-from ground sloths like the elephant-size Megatherium to the marine forager Thalassocnus. In this populous family gallery, various species extinct and otherwise pose in leafy settings, often looking up to make eye contact with viewers. The author surrounds their shaggy figures with specific details of their ranges, diet, distinctive characteristics, and (for the modern exemplars) unique physical adaptations for living in trees. Modern sloths' leisurely ways turn out to be just the ticket, she explains, for an efficient, low-energy lifestyle and for avoiding the notice of predators. Considering they've survived for more than 40 million years, they can't be quite the "slackers" their common moniker implies. Along with all the scientific grist, she also notes that while prehistoric sloths "weren't all that cute," modern ones are totally adorable, with babies "hardwired for hugging" and three-toed adults bearing "peaceful smiles" beneath bandit-like masks. "And now…it's time for a sloth slumber party!" she concludes, beneath a final image of a smiling snoozer comfortably sacked out in a leafy bower.Fetching and informative. (timeline, author's note, resource list) (Informational picture book. 6-8)

Gr 2–5— This informational book about sloths is full of fascinating information about these peculiar creatures. Shreeve introduces each of the six species in the sloth family tree, and key elements such as habitat ("tree huggers"), eating habits ("leaf munchers"), and physical characteristics ("adorable"). Additionally, she describes the range of prehistoric sloth species, comparing them to their modern counterparts and going back and forth in time in a repeated pattern. Fun tidbits—such as the fact that due to their slow metabolism, sloths only poop once a week—and playful language—like comparing the size of a pygmy sloth to a "slightly chubby chihuahua"—appear throughout. Illustrations demonstrate a clear study of the sloth, as each of the depictions is unique, expressive, and lifelike. Their faces are particularly compelling and draw readers into the page. The texture of the intricate etchings making up the sloth's fur stands out against the blurred and smudged trees and foliage. VERDICT An engaging and informative inquiry into the world of sloths, past and present. Recommended for purchase for animal collections.— Clara Hendricks