Trudging through a scorching desert, two young Tarchia find relief at an oasis and encounter an adult twice their size, ready to lay claim.

In a drought-stricken basin where much has perished, an old Pachycephalosaurus bull defends his leadership against a young challenger.

Deep beneath the water's surface, the world's largest predator—the Mosasaurus—lies in wait to ambush unsuspecting prey.

Not many can intimidate North America's top predator, T. rex, whose size and bite are a deadly combo—except for a giant winged foe.