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 on 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. There has now been a decade of Ice Age films, allowing the characters voiced by Ray Romano, Queen Latifah and John Leguizamo to become increasingly familiar to audiences, particularly international ones. The film had already done robust overseas business ahead of opening in the U.S. This weekend it earned *95 million internationally, bringing its overseas total to *339 million.