Twenty thousand years ago, when glaciers covered the earth’s surface, our ancestors roamed the plains, holding stone-pointed spears and stalking colossal mammals—sloths as tall as trees, saber-toothed tigers with shearing bites, the mastodons, and mammoths. Blue Sky Studios and 20th Century Fox focus on this ferocious period of prehistory in their first full-length digitally animated film, Ice Age. The director, Chris Wedge, won an Oscar for his animated short "Bunny" and played a big part in developing the company’s lighting software, which gives the setting an organic realism. The studio consulted a slew of archaeologists and researched at New York’s Museum of Natural History. The result is a digital tour-de-force with a complex look and feel. Unlike the hard plasticine sheen of earlier CGI efforts, best suited for talking robots and bugs, Ice Age follows an unlikely "herd" of furry misfit mammals (as in Shrek). On the morning of the southern migration, Sid (voiced by John Leguizamo), the lazy, wisecracking sloth, oversleeps and his family leaves without him. He hitches a ride with Manfred (Ray Romano), a compassionate mammoth who has lost his wife and child to human hunters. Meanwhile, a pack of vengeful saber-toothed tigers are seeking payback on the tribe’s chief, a brawny warrior who wears their skins on his back. The cats plan to snack on the warrior's son, but Sid and Manny spoil their plans and protect the child. Soon a saber-toothed scout, Diego (Dennis Leary), talks our reluctant heroes into delivering the baby back to the human tribe, so long as he can guide them. Of course, the sly cat has his own selfish motivations. The film opens with the usual dose of slangy, lowbrow humor but thankfully settles into a more thoughtful mode, a welcome change from the breakneck speed of most kiddy fare, unless your attention span rivals the scrat’s, a jittery saber-toothed squirrel/rat who makes cameos throughout the movie as an ongoing punchline. Like Sisyphus, the doomed champion in Albert Camus’s absurdist retelling of the myth, the tiny scrat rolls his acorn to the top of an ice-encrusted mountain, whence his prize tumbles back of its own weight. There is no more dreadful punishment than hopeless labor. The casting is perfect, especially Leguizamo, who adopts a lisp and a sputtering tick to complement the sloth’s penchant for slapstick. Blue Sky proves itself a formidable rival to DreamWorks and Disney. When we watch an animated movie, whether hand-drawn or computer-generated, we shouldn’t think, "That’s good animation." We should think, "That’s a good film." Each individual whisker casts a shadow. Flowing waterfalls and falling snow also lend a credible atmosphere. Although these bumbling creatures shouldn’t share anything in common except the food chain, the moral of the story is cooperation. We get a glimpse of each character’s needs, whether they munch on meat or opt for a vegetarian plate, so no particular animal, not even those who stand on two feet, comes across as a villain. Instead, the film accentuates familial love with a philosophical bent on the theme of perseverance. [rating: 3 of 4 stars] Distributor Web site: Twentieth Century Fox Movie Web site: Ice Age     Photo credits: © 2002 Twentieth Century Fox. All rights reserved.