LOS ANGELES (AP) ― “Dr. Seuss’ The Lorax’’ raked in all kinds of green, earning $70.7 million in its first weekend to score the biggest box-office debut of the year by far.

The 3-D animated family film from Universal Pictures, featuring the voices of Danny DeVito, Zac Efron and Taylor Swift, is based on Seuss’ cautionary fable about the importance of preserving the environment. Of its opening haul, $5.4 million, or 8 percent, came from IMAX screens, which is on the high side for a family film.

Coming in second place with a strong debut of its own was the R-rated “Project X,’’ about a trio of high school misfits who throw a raging party in hopes of becoming popular. The Warner Bros. comedy made about $20.8 million, according to Sunday studio estimates.

“The Lorax’’ comes from the makers of “Despicable Me,’’ ― Illumination Entertainment, led by producer Christopher Meledandri ― and director Chris Renaud. It actually had a bigger opening than that film, which debuted with $56.4 million in July 2010. It also scored the biggest opening for a Dr. Seuss adaptation, topping the $55.1 million that “How the Grinch Stole Christmas’’ made in 2000.

Before this, “The Vow’’ had the best debut of 2012 with $41.2 million.

“I was stunned from Friday,’’ when “The Lorax’’ made $17.4 million, said Nikki Rocco, Universal’s president of domestic distribution. It then made a huge leap on Saturday, earning $31.3 million. “Who would have expected a result like this?’’

Rocco attributed the movie’s success to “a combination of a) a great film, b) an incredible marketing campaign and b-plus) the need for another family film in the marketplace. I think that has a lot to do with it. ...

“People love Dr. Seuss,’’ she added, “and audiences now know about Illumination and Chris Meledandri, what he delivers.’’

The strong showing for “The Lorax’’ continues a trend of movies overperforming so far this year, said Paul Dergarabedian, box-office analyst for Hollywood.com. Revenues are up 19 percent from this point in 2011.

“It’s so different from what we were seeing last year and especially the end of last year. Now it’s like a box-office bonanza,’’ Dergarabedian said. “What a great turnaround from where we were last year with the down-trending week after week and the lowest attendance in 15 years. If we keep up this pace, we’re going to be looking at a massive summer.’’

Some huge sequels are coming out this summer, Dergarabedian pointed out, including “The Avengers,’’ “The Dark Knight Rises’’ and “The Amazing Spider-Man.’’