The prehistoric beasts of Ice Age (2002) deal with thawing glaciers in this sequel, which is, appropriately, warmer than the original. Improved CGI renders the animals’ bodies in greater detail, but the laughs aren’t as sharp, largely because Diego the saber-toothed tiger (voiced by Denis Leary) has been defanged (so to speak) as part of a cozy domestic circle organized by the goofy sloth Sid (John Leguizamo). The new villains—early ancestors of the shark and crocodile—are poorly developed, perhaps so as not to impede the movie’s lessons about overcoming fear and redefining family. Carlos Saldanha directed. PG, 90 min.