Credit: Blue Sky Studios

The bar for 3-D animated movies has been set high. This year alone, the skewed demonic fairy tale Coraline, the pop-up-book clever Monsters vs. Aliens, and the wondrous and heart-lifting Up make tough acts to follow. So maybe that explains why Ice Age: Dawn of the Dinosaurs has a little trouble measuring up. After a sensational opening few minutes, in which Scrat the saber-toothed squirrel does high-flying battle with the squirrel he loves (all for a tasty acorn), the movie settles into a mode of nice, sweet, safe, and — sorry, I have to say it — slightly dull family fun.

Our glacier-happy regulars have been hanging out for so long now that they seem a bit jaded. Manny and Ellie (Ray Romano and Queen Latifah), the woolly mammoths, are set to have a baby, and Diego (Denis Leary), the saber-toothed tiger, is still a freelance grouch. Leave it to Sid (John Leguizamo), the lisping sloth, to discover three cuddly baby T. rexes, who lead them all to a viny green prehistoric jungle packed with dinosaurs. A fight with a massive carnivorous plant is neatly executed, and the whole trippy-fauna look of the movie is lost-world magical, but Dawn of the Dinosaurs just isn’t very funny. It lopes and slogs where the first two Ice Age movies popped. B-