A bull Tyrannosaurus sculls across the shallow warm waters of an inland sea, a gang of fluffy chicks in tow. His great chest labors with powerful snorting breaths, his chin wavering with the effort of keeping his head above water. Some months previously, the bull courted a female who wandered into his territory, arching his chin in a coy welcome; now he’s got babies to care for as he leads them across dangerous waters in search of new opportunities. This is the image that opens Prehistoric Planet, an astonishing new five-part documentary miniseries airing this week on Apple TV+. Hosted by David Attenborough and filmed by members of the acclaimed BBC Studios Natural History Unit, the show offers a wide-ranging tour of the earth's landscape 66 million years ago, crossing the lush forests and polar crags of western North America, the baking deserts of Central Asia and South America, and the flooded islands of Europe. The Tyrannosaurus scene, rendered in remarkably crisp and...