NEW YORK (AP) — With Batman lurking, the prehistoric critters of Ice Age: Continental Drift ran off with the box office, earning US$46 million in their opening weekend, according to studio estimates yesterday.

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 instalment, The Meltdown, which opened with US$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 US$95 million internationally, bringing its overseas total to US$339 million.

"Scrat rules the world," said Chris Aronson, head of distribution for Fox, referring to the films' rat-squirrel mascot, whose wordless, futile pursuit of a nut is a mainstay of the movies.

The Ice Age franchise has now surpassed US$2.2 billion worldwide, and the studio expects "Continental Drift" to equal the global total of the last instalment, 2009's "Dawn of the Dinosaurs," which took in US$886.7 million.

"There's really not very many animated franchises that have had three sequels," said Aronson. "The performance of 'Ice Age' has been remarkably consistent."

The weekend was inevitably shadowed by two superheroes, coming a week after the debut of Sony's Spider-Man reboot, "The Amazing Spider-Man," and one week before the highly-anticipated Batman sequel, "The Dark Knight Rises."

In its second week of release, "Spider-Man" earned $35 million, pushing it past $200 million domestically. It earned nearly $67 million overseas over the weekend, bringing its worldwide gross is now $521.4 million.

Seth MacFarlane's R-rated comedy hit, "Ted," which stars Mark Wahlberg and a talking teddy bear, added $22.1 million in its third week for a total of $159 million for Universal Pictures.

But the weekend belonged to family films, which had three of the top 10 films at the box office.

"Ice Age" is the third animated blockbuster to debut at No. 1 this summer, and the previous mega-cartoons — Pixar Animation's "Brave" and DreamWorks Animation's "Madagascar 3: Europe's Most Wanted" — also padded their totals. In fourth place, "Brave" added $10.7 million to its $195.6 million domestic total, and the 10th place "Madagascar 3" added $3.5 million to its $203.7 million domestic total.