Walker (Seahorse Reef, 2001, etc.) imbues a still-ongoing scientific treasure hunt with all the suspense and excitement it deserves. Drawing information from both published sources and private interviews with research scientists, she chronicles the modern rediscovery of this lumpish, rugged-looking fish, once thought extinct for 70 million years. Her account covers its chance 1938 appearance in a fisherman’s net to finds within the last five years that have extended its range to Indonesia and several spots along Africa’s eastern coast. Enhanced by lucid art and sharp color photos, and backed up with helpful book and Web site lists, she produces an engrossing tally both of what we know about coelacanth anatomy and behavior, and what remains mysterious. No captured specimens have yet survived more than a few hours, no young have ever been observed, and the purpose of certain organs is still unknown. She makes it easy to understand why, though “it’s usually people that catch coelacanths, something about coelacanths also ‘catches’ people.” Science-writing at its finest, sure to net plenty of young readers. (Nonfiction. 11-13)