Not even 3D can save this third entry in the Fox animation franchise about a motley crew of prehistoric creatures. This time they face threats from beneath the earth’s frozen crust, as Sid the sloth discovers a trio of dinosaur eggs, adopts the hatchlings, and earns the wrath of their mama, a Tyrannosaurus rex. Simon Pegg provides the voice of a buccaneer weasel that leads the gang through one chase after another; the manic pace quickly grows tiresome, as does the influx of cloying baby animals. Carlos Saldanha and Mike Thurmeier directed; among the other voice talent are Ray Romano, Queen Latifah, Denis Leary, and John Leguizamo. PG, 87 min.