With Batman lurking, the prehistoric critters of "Ice Age: Continental Drift" ran off with the box office, earning $46 million in their opening weekend, according to studio estimates Sunday. The animated film from 20th Century Fox is the fourth in the "Ice Age" series and the first in 3-D. The North America performance of "Continental Drift" was on par with previous "Ice Age" movies but well below the opening weekend of the second installment, "The Meltdown," which opened with $68 million in 2006.
