Watch marbles zoom through a prehistoric adventure! GraviTrax Junior Dinosaur Starter Set S brings the dino world to life with awesome T-Rex and Sauropod figures plus all the track pieces kids need to build right away. Perfect for ages 3+, this wooden bioplastic set lets little builders create their own themed worlds while developing motor skills and spatial thinking. As marbles roll and tumble, kids discover cause and effect in action—all while imagining epic dinosaur adventures. Mix, match, and rebuild again and again with expandable pieces for endless creative fun!