TORONTO - The filmmakers behind the new 3-D animated feature "The Croods" admit they didn't exactly stick to palaeontology records when crafting the story of a primitive family's first trip away from home.
For one thing, they set the DreamWorks comedy in a fictional "Croodaceous Period" filled with fantastical landscapes.
And the creatures depicted don't come from history books. Rather, they're hybrids — from a Crocopup to Piranhakeet and Mousephant.
As for the Croods themselves, well, they're more a blend of both Homo sapien and Neanderthal, says co-writer and co-director Chris Sanders.
"Warning: do not base your book report on this film," he said with a laugh during a recent telephone interview.
Opening Friday, "The Croods" features Nicolas Cage as the voice of stubborn and fearful prehistoric father Grug, whose strict rules for keeping his family safe around their cave has teenage Eep (Emma Stone) feeling trapped.
When Eep sneaks out one night, she meets smart and free-spirited Guy (Ryan Reynolds), who warns that a disaster is about to befall the area and they should flee to a place called "Tomorrow."
The two manage to convince the clan — which also includes wife Ugga (Catherine Keener), son Thunk (Clark Duke), and Gran (Cloris Leachman) — to embark on an adventure filled with fun and dangerous seismic shifts.
The story idea began in 2005, when co-writer and co-director Kirk DeMicco began penning a stone-age comedy with "Monty Python" star John Cleese.
At the time, the project was more a buddy comedy featuring a technological inventor and a luddite caveman.
"It was really about the fear of technology and invention," said DeMicco, who also co-penned with Cleese an adaptation of the Roald Dahl book "The Twits" that's in development for Disney.
"John has a healthy fear of technology, that it might ruin the world, so it was something of interest to him."
When Sanders joined the project a few years later, they continued that theme of the fear of change but made it more about changes in a family.
"Especially for a father who has to witness the changes of his teenage daughter about to leave and possibly be with a man or a boy that he doesn't agree with," said DeMicco.
Vancouver native Reynolds was perfect for the voice of adventurous Guy because he could inject him with emotion and intellect that doesn't "come off as being elitist or looking snotty," said DeMicco.
"It felt like Ryan figured out a way, you know, he can be charmingly superior," he added.
"Like a lot of his stuff, especially the comedy stuff, he comes across as still very warm but he's slightly above."
Another key character is Belt, Guy's sloth-like furry friend.
DeMicco and Sanders were inspired by a real sloth they used in a comical short video for their final presentation to DreamWorks staff.
"We wrote this little story about how we actually didn't make the film, it was a sloth that wrote the entire thing and directed the actors," said Sanders, whose other animated film credits include "The Lion King," "Beauty and the Beast" and "Mulan."
With that, they filmed a real, 38-pound sloth named Lola, who came from a wild animal movie rental business.
"She is such a sweet girl and all she did was fall asleep," said Sanders. "We'd put her in a chair for a shot and she would fall right to sleep and then we'd give her Hibiscus to wake her up."
Lola's sweetness was slightly offset by her huge fangs, though.
"That are honestly the most razor-sharp things I've ever seen, because her lower and upper fangs as she closes and opens her mouth rub against each other," he added.
"It's like a pair of scissors. Every times she closes and opens her mouth, she sharpens those teeth, and so if she did mistaken you for a leaf and grabbed you and put your finger in her mouth, she would bite right through your finger like it was nothing."