The animated adaptation of a beloved children's book by Dr Seuss hit big screen this weekend in North America with an elephant-sized box office, and became the strongest-opening movie this year.

"Dr Seuss' Horton Hears A Who" is on track to sell US$45.1 million in tickets at US and Canadian theaters over the three-day-period, according to preliminary figures released yesterday by box office tracking firm Media By Numbers.

The 20th Century Fox release, with voices of famous comedians like Jim Carrey and Steve Carell, is the third big-screen Seuss adaptations, after 2000's "How the Grinch Stole Christmas" and 2003's "The Cat in the Hat."

The new film was earlier expected to have a huge weekend, possibly breaking the US$55-million, but its performance of over US$11,000 per theater was nothing to sneeze at.

Its opening was still a good 10 percent higher than thriller "Cloverfield," the surprise box office hit that opened with a US$40-million weekend earlier this year, according to Media By Numbers.

Fox officials now expect Horton's box office appeal would extend through the coming Easter weekend and beyond, as students are out of school for the spring break.

Two other movies that debuted in the top ten this weekend were "Never Back Down," in third place with US$8.6 million, and number-seven "Doomsday," with US$4.7 million.

Last week's box office leader, "10,000 BC" slipped to No. 2 with US$16.4 million over the weekend, while Disney comedy "College Road Trip" and Sony Pictures' anti-terror thriller "Vantage Point" were at No. 4 and No. 5, with US$7.9 million and 5.4 million respectively.

Meanwhile, overall box office revenues in North America were estimated at 127 million dollars over the weekend, up some 8.5 percent from the same weekend last year.