It seems that the imminent parenthood of woolly mammoths Manny and Ellie (Ray Romano and Queen Latifah), threatens to break up the old gang that includes saber-toothed tiger Diego (Denis Leary) and sloth Sid (John Leguizamo).
Although until now the Ice Age creatures have been happily heterogeneous, Manny and Ellie seem as though they might retreat into a mammoths-only universe, leaving their pals in the cold. So worried is Sid that Manny and Ellie are expecting and that he will be forever displaced that he adopts three eggs he finds in a cave. They become Tyrannosaurus hatchlings.
The visual idea behind the movie is to put the Ice Age creatures into an unfamiliar Jurassic landscape. The film's plot, if one can call it that, involves the return of the Tyrannosaurus Regina to reclaim her hatchlings and take Sid to a lush, tropical underworld so different from Sid's familiar icy territory.
Though there are chases galore and stampeding dinos aplenty, Dawn of the Dinosaurs is a nicely rendered travelogue without storytelling. There is little to bring an audience along for the ride.
This said, the film's animation art is Seuss-imaginative. And it deploys its 3-D wisely, to show the depth of valleys, the crystalline texture of snow, and the molten glow of lava. The depth of these effects serves mostly to make the flatness of the story and indifferent voicework all the more obvious.
Director Carlos Saldanha did such an excellent job infusing the second installment with energy that it's a shame he was unable to do the same with Part 3.
The liveliest aspect to Yawn of the Dinosaurs is Buck (voice of Simon Pegg), a hyperkinetic, piratical one-eyed weasel reminiscent of the lemur voiced by Sacha Baron Cohen in Madagascar. Buck has the effect on the movie that a candy bar has on a hungry kid: First the sugar rush, then the crash.
Contact movie critic Carrie Rickey at 215-854-5402 or firstname.lastname@example.org. Read her blog, "Flickgrrl," at http://www.philly.com/philly/blogs/flickgrrl