ALA Booklist (Tue Jun 01 00:00:00 CDT 2021)

Young fossil enthusiasts will be fascinated by this story of the Ashfall Fossil Beds, which begins with the 1953 discovery of a skull and jaw of a rhino in Nebraska. More amazing was geologist Mike Voorhies' 1971 discovery of an entire baby rhino fossil and, in 1977, of dozens more rhino skeleton fossils. This book describes the scientific research that Voorhies and others conducted to confirm that the fossil remains were from almost 12 million years ago, when Nebraska was a savanna ecosystem. They discovered that these animals suffocated from ash after a supervolcano erupted thousands of miles away. The book recounts the efforts of Voorhies and others over the past 50 years to preserve these amazing fossils at the dig site for future generations to enjoy. As of 2021, more than 350 fossil animals and 250,000 bones have been found. Huynh's strikingly bold black-and-white illustrations supplement black-and-white photos and solid back matter. Ideal for fossil hunters and readers interested in observing how scientists prove theories based on scientific evidence.

Horn Book (Sun Aug 01 00:00:00 CDT 2021)

For many years, people in northern Nebraska found fossilized bones so often around a certain hillside that they called it Bone Hill. Over the course of several decades, multiple teams of scientists came to discover a treasure trove of complete animal skeletons fossilized in the ashy ground surrounding Bone Hill. But the fossils were so delicate that, instead of transferring them to a lab somewhere, workers built a lab around the hill, creating the space that would become the Ashfall Fossil Beds, a state park where visitors can still view scientists at work. Stevens starts by describing the ancient creatures that roamed Ashfall, then discusses the supervolcano whose ash was the animals' demise. With this intriguing hook in place, she moves on to the scientists' work to discover the mysteries behind the abundant fossil remains at Ashfall. Black-and-white photos alternate with Huynh's comic-style spot- and full-page art to bring the scenes to life. Stevens's light tone ("How did the researchers know the young rhinos' ages? They couldn't very well ask them. But they could [and did] check their teeth"), short chapters, and plenty of white space should appeal to many young fossil-hounds, although excessive detail in some places may leave less-enthralled readers in the dust. Words in bold appear throughout, defined in a glossary at the back; an author's note, resources for further study, and an index are also appended. Sam Bloom

Kirkus Reviews

Scientific investigation of a quarry in Nebraska reveals that 12 million years ago it was a very different world.Science writer Stevens describes the process of finding and identifying a treasure trove of extinct animals-full skeletons-buried in volcanic ash from an eruption in today's Idaho. There were rhinos, horses, camels, saber-toothed deer, birds, turtles, and even bone-crushing beardogs. She recounts the ways scientists have worked together and separately since 1953 to excavate specimens, date ash layers, deduce animal behavior, figure out their environment, and identify the volcano. Poison Ivy Quarry became Ashfall Fossil Beds State Historical Park, where fossils continue to be revealed but are left in place; visitors can observe the ongoing research. Realistically, she includes some of the hiccups and dead ends. She introduces scientists, interns, and students from various fields. Her clear exposition includes examples of the clues that inform their deductions about the animals and their environment, helping readers understand how these researchers arrive at their conclusions. She explains less-familiar techniques, concepts, and equipment such as topographic maps, radioactive dating, convergent evolution, scanning electron microscopes, plate tectonics, and ground-penetrating radar. Specialized vocabulary is printed in boldface and defined both in context and in a glossary. Huynh's brush-and-ink paintings are an inspired addition to this account of the work of re-creating a long-distant history; there are also helpful black-and-white photographs.Welcome evidence that paleontology is about more than dinosaurs. (author's note, resources, acknowledgments) (Nonfiction. 9-14)

Publishers Weekly (Fri Oct 06 00:00:00 CDT 2023)

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)

School Library Journal (Thu Jul 01 00:00:00 CDT 2021)

Gr 5 Up-This title explores the surprising discoveries made at Nebraska's Ashfall Fossil Beds over a 50-year span, including information about new species, geological events, and animal behavior. At the same time, Stevens provides fascinating insights into the techniques scientists use to reconstruct the ancient past. The writing is lively, clear, and sometimes conversational. Fluid nonfiction storytelling presents the research in terms of mysteries to be solved, and readers gain an increasingly fuller picture of the work and its results with each new revelation. The author does a nice job of introducing material, then building upon it in subsequent chapters. The process of pinpointing the dates of the fossils, for example, involves three different methods over time, each one further solidifying theories. Explanations of key concepts such as evolution or fission tracks are clear and supported neatly by examples. The logistics of this huge, multiyear project emerge in different ways, such as the careful methods used to avoid damaging specimens and the need to bring in experts in various fields to uncover the full truth. Short, well-organized chapters help to break up the wealth of information into sections without overwhelming readers. The chronologically arranged narrative conveys the passage of several decades, but dates are usually not provided for specific events. Visual support is provided with black-and-white drawings of the ancient creatures, along with occasional diagrams and photographs of fossils. VERDICT Engaging science content for older readers who love paleontology. Steven Engelfried, Wilsonville P.L., OR