Rhinos in Nebraska: The Amazing Discovery of the Ashfall Fossil Beds

Three-toed, dog-size horses; four-tusked elephants; and barrel-bodied rhinos are just some of the creatures that dotted the grasslands of Nebraska 12 million years ago, revealed in this accessible nonfiction tome by Stevens. Drawn to a seasonal water hole, the animals became fossilized after a supervolcano erupted and covered the landscape in ash, remaining undisturbed until 1953, when a rhino skull was found, and then the 1970s, when geologists revisited the Ashfall Fossil Beds. Stevens skillfully narrates the journey dozens of scientists undertook to excavate, identify, and preserve the fossils, unpacking concepts in simple prose, as in this explanation of modern horses’ lack of three toes: “Growing toes (or any other body part) takes energy. When animals no longer need the body part, it often gets smaller or disappears completely.... It’s a slow process that takes place over many generations.” B&w photographs and folk art–style brush-and-ink illustrations by Huynh lend atmosphere. The book’s second half, describing the less dramatic scientific work of ground-penetrating radar and electron microscopes, feels perhaps overly long, but this is an intriguing primer on lesser-known paleontological subjects. Back matter includes a glossary, author’s note, and resources. Ages 8–12. (July)