Ice Age: Dawn of the Dinosaurs

To answer the obvious question, the makers of “Ice Age: Dawn of the Dinosaurs” are well aware that the dinosaurs came and went long before the film takes place. What happened, though, is that some of the dinosaurs survived in a huge, cavernous world underneath the ice, and in this sequel our mammalian heroes stumble across them. So it’s not a “dawn of the dinosaurs” so much as an “accidental discovery of a few leftover survivors of the dinosaurs.” But that would have been too unwieldy a title.

The third film in the series isn’t as funny or inspired as its predecessors (which weren’t exactly brilliant to begin with) and occasionally feels desperate. The very premise — somehow the main characters find some dinosaurs! — sounds like a last resort, the kind of plot a sitcom resigns itself to using in its seventh or eighth season, after all the good stories have been used up. But the film serves its target audience well enough (as long as the several penis-related jokes go over their heads, anyway) and offers a series of pleasant smiles if not a lot of gut-busting laughs.

Manny the mammoth (voice of Ray Romano) is coupled with Ellie (Queen Latifah), the she-mammoth he met in the last film, and they are expecting a baby any day now. One assumes they are legally married and not simply living in sin. (Hey, if you’re going to anthropomorphize the animals, go all the way with it.) With motherhood in the air, Sid (John Leguizamo), the idiot sloth who functions as the mammoths’ wacky next-door neighbor, slips through a crack in the ice and finds three huge eggs that he believes to be abandoned, so he takes them home. When the baby Tyrannosaurus rexes hatch from the eggs, Sid is thrilled to be their surrogate mother. Less thrilled, obviously, is their actual mother, who comes a-callin’ soon enough.

As mentioned, the dinosaurs live under the ice, apparently unaware (or unconcerned; none of them talk) that mammals thrive above them. Theirs is a lush, tropical world that manages to sustain all manner of flora and fauna despite receiving no sunlight. Manny, Ellie, Diego the tiger (Denis Leary), and the possum brothers (Seann William Scott and Josh Peck) venture into the subterranean world when Sid is taken away by the angry T. rex, and are aided in their travels by Buck (Simon Pegg), an insane Rambo-ish weasel who lives down here like a survivalist enjoying his grand adventure. (“Let me tell you about the time I used a sharpened clam shell to turn a T. rex into a T. Rachel,” he says.)

Buck provides most of the film’s laughs simply by being its freshest, most out-there character. Manny and Ellie have lapsed into dull domesticity, Sid’s dumbness has worn thin, and Diego — well, poor Diego doesn’t even need to be in the movie. The screenplay (credited to five writers!) spends about 30 seconds suggesting he’s losing his edge being part of a “herd” and needs to strike out on his own, then abandons the subplot as if it never happened.

But the most inspired lunacy, as always, is courtesy of Skrat, the hapless squirrel-like creature who’s forever in search of an acorn. His misadventures, which this time involve a female of his species who competes with him for the nut, recall the slapstick glory of the Looney Tunes. At one point, there is a parody of “Alone Again (Naturally)” written from the point of view of the acorn. Yes, the acorn. If the rest of the movie — cheerful, bright, but not very memorable — were half as creative as that single idea, it would be something truly worth discovering.

B- (1 hr., 34 min.; PG, a few mildly naughty references, minor scariness.)