In the game, players play in both the present and the far past. In the past, players are moving around dinosaurs and trying to place them so that their present-day paleontologists can find the fossils they leave behind. Ultimately, the paleontologists are looking to get specimens to attract people to their museums. Perhaps a touch morbid, as you're trying to get your dinosaurs killed in "just the right spot" but hey, it's supposed to be a more light-hearted sort of game.
From the campaign:
Each turn, players will move on both boards. On the Dinosaur Board, they will be controlling the destiny of the dinosaurs. As these giant (yet fragile) creatures stumble around the island, they will succumb to tar pits, landslides, meteors, hunger, temptation, and all sorts of other devilish prehistoric traps. As they die, their remains appear on the island of the future as fossils, ready to be excavated.
On the Paleo Board, playing as paleontologists, players will race to explore the jungle, expand their territory, and dig up as many fossils as they can get their brushes and pickaxes on. As you assemble these fossils, you send them off to a museum on the mainland where children will hopefully be spilling over the velvet ropes to view the dusty old bones. The better your fossils, the more visitors will come streaming through your door. Have enough visitors to your museum and you will be crowned the victor! You brave paleontologist, you.