"Over the millennia many creatures have come and gone, but six unusual animals have survived and changed very little. From numerous possibilities, Hirsch has chosen six examples of animals that could be called 'living fossils,' although she makes clear that, like other life on Earth, they've evolved over time. In choosing, she also looked for animals with uncommon traits, highlighted in her descriptions. Her selections--horseshoe crabs from the Atlantic coast, chambered nautilus from the Indian and Pacific oceans, West African lungfish, tuatara from New Zealand, duck-billed platypus from Australia, and selenodon from Hispaniola--are a combination of familiar and surprising. Each animal gets two or three spreads, including a full-page photograph, a nicely written introduction, and a box with fast facts. Photos are nicely captioned, but they don't always indicate magnification. An introductory chapter introduces the theories of evolution and natural selection and discusses the way a living fossil, such as the velvet worm, still so like Aysheaia from the Cambrian era, actually has evolved. It includes a timeline.

A final spread reminds readers that living fossils, who've survived major extinctions, are threatened again by a human-caused sixth. Well-organized, clearly written, nicely designed, and including new research, this will be welcomed in libraries, even those already owning Caroline Arnold's Living Fossils: Clues to the Past, illustrated by Andrew Plant (2016), which describes some of the same intriguing creatures. (This book was reviewed digitally with 8.875-by-20.5-inch double-page spreads viewed at TK% of actual size.) A satisfying selection of nature's survivors for readers intrigued by the animal world."--Kirkus Reviews.