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.

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.

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

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

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

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

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

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

On a small island, a monumental display takes place as the giant Hatzegopteryx reveals his gentler side to woo a mate.

On a small island, a monumental display takes place as the giant Hatzegopteryx reveals his gentler side to woo a mate.