It was a weekend of firsts at the box office.
The No. 1 spot went to the first cave-man family in "The Croods," and "Olympus Has Fallen" star Gerard Butler had his first strong showing at the multiplex in years.
The 3-D animated family film beat out the competition, grossing a solid $44.7 million, according to an estimate from distributor 20th Century Fox. "Olympus Has Fallen," a White House-set action thriller, exceeded industry expectations by about $10 million, debuting with a healthy $30.5 million.
Meanwhile, the Tina Fey-Paul Rudd comedy "Admission" started off with an underwhelming $6.4 million. And...