Stan and Jan Berenstain invite readers to help solve a mystery in this beloved Beginner Book. When a dinosaur bone goes missing from the Bear Museum, it's up to the Berenstain Bears to help crack the case. From the Mummy Room to the Hall of Famous Bears, the detectives seek every possible hiding place. Can Brother and Sister Bear find the culprit in time for the museum's grand opening? Beginner Books are fun, funny, and easy to read! Launched by Dr. Seuss in 1957 with the publication of The Cat in the Hat , this beloved early reader series motivates children to read on their own by using simple words with illustrations that give clues to their meaning. Featuring a combination of kid appeal, supportive vocabulary, and bright, cheerful art, Beginner Books will encourage a love of reading in children ages 3-7.