Part 5: Spirits of the Ice Forest ("of the Silent Forest" in the book)

Time: 106 million years BCE

Place: "Antarctica," part of a giant continent made up of present-day Antarctica, South America, and Australia

Actual Locations: New Zealand

The setting and cast of this episode are the most unfamiliar for the veteran dinosaur watcher. Most of the action takes place in a silent forest a few hundred miles from the South Pole, a locale that simply didn�t exist in past popular saurian narratives. It�s a cold, harsh world that is dark for months on end; everything shows up in a washed-out grey-green. But it�s not a wasteland or an ice sheet: it�s a dense forest of ferns, conifers, swampy pools � and the huge flat head of what looks like a bullfrog pops out to snatch at the corpse of a small dinosaur on the shore!

The star of this show is Leaellynasaura (sounds like "Lianna-saura"; was it discovered and named by a Welshman?), an elegant 7-foot biped with�wait for it�huge eyes "and an enlarged optic lobe that enabled it to see in the dark." There�s plenty of animatronic action with these creatures, who warn one another of predators and scatter; build nests of rotting leaves to incubate eggs whose temperature they monitor with sensitive beaks; and chase off an egg-snatching mammal called Steropodon, a secondary cuddly hero who looks like a cross between an opossum and a raccoon.

Koolasuchus is the heavy: 16 feet long but only 1 foot high, it looks like a giant, squashed salamander with an outsized arrow-shaped head. It�s actually a throwback to a time before the dinosaurs: an amphibian that survived only in the polar regions because it was too cold for crocodiles. Koolashuchus hibernates in the swamp during the winter, and makes a laborious 200-meter crawl to its summer quarters in the river. A Dwarf Allosaur, "only" 20 feet long, provides some additional threat to our cuddly heroes as well.

The big dumb-guy role is taken by Muttaburrasaurus, an herbivore whose enlarged snout (the head looks like a camel�s with yellow balloons on its nose) may have been useful for making distinctive calls. We get a closeup of blood-sucking insects on its ears and eyes. A lizard known as the Tuatara, another reptile that predates the dinosaurs but will live on into present-day New Zealand, makes an appearance, as does the Weta, a giant brown cricket-like insect.

As the lighter part of the year winds down, plant photosynthesis stops, Southern Lights dance across the sky, there�s a time lapse sequence of ice crystals and creamy ice forming on various objects, and the scene turns almost pitch black under the trees. "But with image-enhancement, it is possible to get a Leaellynasaura�s-eye view of the clan," says Branagh, and the visuals of frozen ground and pools, of the clan gone into suspended animation, resemble infrared photography.