Australopithecus are shown without any clothes, making them somewhat nude. However, they are covered by fur like chimpanzees and bonobos, the closest living relatives of humans.

Two large animals mate. Male genitalia is shown briefly and from a distance.

A lot of prehistoric animals die on and off-screen. It is also stated by the narrator that some surviving prehistoric animals have died out to extinction.

A species of pig-like animals are occasionally referred to as "Hogs from Hell"

The Entelodonts and Hyaenodons may terrify children, with the Entelodonts looking like real life monsters and the Hyaenodons hunting a baby Indricothere at night.

The Brontothere (Embolotherium) mother's calf dies and is eaten by a pair of Andrewsarchus. This scene may be distressing to many children and/or parents.

The predatory Gastornis kills an early horse (Propalaeotherium). This could scare kids. Despite the fact that real Gastornis was proven to be purely herbivorous or mostly herbivorous, the show was made before the discovery.

A Deinotherium (an extinct giant elephant relative) charges at a group of Australopithecus and nearly tramples the infant Australopithecus to death in dramatic slow motion, which could scare and/or sadden viewers thinking the infant Australopithecus was killed. However, the infant Australopithecus survives the encounter.

This series contains frequent scenes of animals hunting, though it is presented in much the same way as in other nature documentaries. Dramatic music accompanies these scenes which may increase anxiety for some viewers.