Geologic time might not register the mere decade that has elapsed since the first Ice Age movie, but in that interval, the animated-franchise world has widened, and now delight dissipates. What keeps this improbably extinction-resistant series alive must be the Sisyphean tenacity of its mascot, the acorn-chasing prehistoric squirrel, Scrat. As is revealed in a Looney Tunes–worthy prologue (formerly the freestanding short Scrat’s Continental Crack-Up), it’s thanks to this one dotty varmint that the supercontinent Pangaea first went to pieces. Thereafter, filler: a family divided by tectonic upheaval, with mammoth Manny (Ray Romano), smilodon Diego (Denis Leary), and sloth Sid (John Leguizamo), plus Sid’s feisty grandma (Wanda Sykes), adrift and imperiled on an iceberg, while on land, Manny’s wife, Ellie (Queen Latifah), monitors their teenage daughter, Peaches (Keke Palmer), newly more into fellow-mammoth cool kids (Drake, Nicki Minaj, Heather Morris) than her doting mole hog pal (Josh Gad). And because that’s not yet plotty enough, Diego, too, gets a love interest, a big kitty with the voice of Jennifer Lopez. Directors Steve Martino and Mike Thurmeier do up the stuff of oceanic epic — pirates, sirens, perfect storms — and seem attuned to their performers, not least an aptly knavish Peter Dinklage as the pirates’ primate captain. But the best bits are basic and all but voiceless: those Scrat-intensive set pieces, still inspiredly squirrelly if much too far apart. Poignant, then, to see Continental Drift preceded by a Simpsons short that’s also dialogue free — and more dolefully funny and narratively controlled than that series has been in years.