The 1974 TV series Land of the Lost, about a family that was sucked into a dimensional portal that dropped them into an alternate universe ruled by dinosaurs and cave people, was a Saturday morning children’s show that ran for three seasons. It later gained a sort of cult classic status despite (or maybe because of) its primitive clunky special effects and its naïve innocence. It was successful enough to have been revived with a different cast in 1991 and ran for two seasons.

The big-screen version of Land of the Lost has spiffy new computer-generated dinosaurs, but just about everything that made the TV series such a charmer 35 years ago has been lost in a torrent of gags that are not as funny as everyone in the cast seems to think they are, as well as a total loss of innocence in the way the characters leer at co-star Anna Friel and incessantly try to grope her.

In the original TV shows the characters were a father, Rick Marshall, and his two children — Will and Holly — who fell down a 1,000-foot waterfall on a camping trip and were pulled into the alternate dimension. In the big-screen version Rick Marshall is played by Will Ferrell as a goofy scientist whose theories about quantum paleontology and a parallel universe have been widely debunked. In a funny opening sequence, Rick is interviewed by Matt Lauer on the Today TV show, when an offhand remark turns it into a fist-swinging free-for-all. It’s the familiar boy-man character Ferrell has played many times in the past — whether it’s as a race car driver or an ice skater — and it’s a role that seems designed to appeal to boys between 10 and 12, which is who this entire movie seems to be aimed at.

But Rick is a never-say-die type. With the encouragement of a pretty biologist named Holly (Friel), he soon has his Tachyn Energy transporter — which also plays songs from A Chorus Line — up and running and ready to transport them, along with a redneck survivalist named Will (Danny McBride), to a place that sort of resembles Earth. But it has three moons, not to mention dinosaurs and cave people in the same era along with familiar earthly trappings that have been deposited in this place after falling into the dimensional portal — a drive-in movie screen, a motel, a Hummer limousine, the Golden Gate Bridge, a Viking ship, a Roman catapult and an ice cream truck among them. The dinosaurs love the ice cream truck, as well as its tasty driver.

One of the furry, orangutan-like Missing Link cave people is named Chaka (Jorma Taccone from Saturday Night Live), who becomes a sort of guide-mascot to the trio of not-so-intrepid travelers, although sometimes his motives are suspect.

There’s also a Tyrannosaurus Rex with a bad attitude that they name Grumpy, just like the TV show’s T-Rex, only this one looks real thanks to a bigger budget and an advance in special effects. (Some of the TV show’s dinosaurs were created using a mix of stop-motion photography and hand puppets.)

Also from TV are the lizard-like creatures called the Sleestak that move very slowly and look like men in rubber suits modeled after the Creature from the Black Lagoon, only bug-eyed.

In past films director Brad Silberling has shown he can do interesting things with fantasy — Lemony Snicket’s A Series of Unfortunate Events and City of Angels are his. But in Land of the Lost he’s saddled with a pompous, ridiculous lead character played overbroadly by Ferrell, along with a series of juvenile jokes and oddball situations that are at best only marginally amusing and at worst sophomoric.

I thought we’d hit bottom already with Night at the Museum: Battle of the Smithsonian. But if nothing else, Land of the Lost actually makes that film look not so bad after all.

*1/2Land of the Lost

Starring: Will Ferrell, Anna Friel, Danny McBride, Jorma Taccone, John Boylan. Matt Lauer.

Rated: PG-13, contains crude and sexual humor, brief profanity.