Count down the five most fascinating fossil finds in this X-Book about monster birds! Kids learn about this Ice Age animal's features, behaviors, and hunting tactics, as well as how it went extinct. Xciting facts and xtraordinary pictures bring history back to life with bite-sized text portions that are perfect for reluctant readers. Includes plentiful sidebars and a graphical design to captivate visual learners along with nonfiction features like a table of contents, index, glossary, and xtra resources.