A pregnant Tuarangisaurus is in distress-and her young calf can sense it-as she travels waters that are home to the ocean's deadliest predators.

Above the deserts of North Africa, aerial combat ensues as male Barbaridactylus pterosaurs fight for the attention of females below.

With its feathered body and duck bill, the eight-ton Deinocheirus wades through an Asian wetland in search of relief from pesky biting flies.

Within the snow-covered forest, a tense standoff develops between ancient rivals, Pachyrhinosaurus and Nanuqsaurus.

A journey through an underground cave in North America turns perilous when a young Triceratops is separated from its mother.