While dinosaurs patrolled the lands, massive prehistoric sharks, giant scorpions, and colossal squid cruised the ancient oceans -- most with just one thing in mind: eat or be eaten. Pop-up masters Robert Sabuda and Matthew Reinhart explore the prehistoric underwater world where monsters like megalodon ruled the waves. Full of captivating facts and more than thirty-five breathtaking pop-ups, this incredible volume is sure to astonish and amaze everyone from budding marine biologists to confirmed landlubbers.