'Ice Age' debuts at No. 1 at box office

With Batman lurking, the prehistoric critters of "Ice Age: Continental Drift" ran off with the box office, earning $46 million in their opening weekend, The Associated Press reports.

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 movie, "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.

"Scrat rules the world," said Chris Aronson, head of distribution for Fox, referring to the films' rat-squirrel mascot.

The weekend was shadowed by two superheroes, coming a week after the debut of Sony's "The Amazing Spider-Man," which fell to No. 2 at $35 million, and one week before the highly anticipated "The Dark Knight Rises."