Oceanhouse Media has released a number of apps based on the Smithsonian 'Prehistoric Pals' print series. Mosasaurus is the latest. If your patrons and students are keen on prehistoric creatures, take a look at some of the other apps from this developer as well as March of the Dinosaurs produced by Touch Press. A few familiar dinosaurs appear—and suspense builds—as viewers dive into a prehistoric ocean moments before Mosasaurus, Mighty Ruler of the Sea (Oceanhouse Media, iOS, Android, Nook, all $2.99; PreS-Gr 2) attacks a pterosaur. The app, based Karen Wagner’s book by the same title (Palm Publishing/Smithsonian, 2008), follows a typical day in the life of its subject animal, a marine reptile with “massive jaws” that “expand for swallowing large prey.” In this story, the creature attacks and eats a crocodile, snacks on ammonites, and wrestles with a larger, territorial Mosasaurus while avoiding a shark. At dusk, viewers get another glimpse of a few other prehistoric animals, as the reptile settles down to rest, still "alert to danger."

Interior screen from 'Mosasaurus' (Oceanhouse Media) Carr

Each screen includes one or two sentences of text against the brilliant blue ocean and detailed images of animals illustrated by Karen Carr. Astute viewers might wonder about the size of the “mighty” Mosasaurus in the app. While endnotes indicate it could reach 55 feet in length and weigh 20 tons, as depicted here it is hard to tell if it comes close to that size. Three listening and reading options are available from the home screen: “Read To Me,”  “Auto Play,” and “Read It Myself.” The first two offer clear narrations, and the opportunity to replay text and listen to names and labels voiced. Children can also record their own reading of the text. Sound effects and music provide added texture. An interactive tale for avid fans of prehistoric creatures.—Debbie Whitbeck, West Ottawa Public Schools, Holland, MI For additional app reviews, visit our Touch and Go webpage.