The story focuses on Rick Marshall (Ferrell), a somewhat pompous paleontologist whose career was waylaid after a disastrous TV interview where his theories of time warps were ridiculed, to which he now works as a lowly job at a Tar Pit tourist attraction. However, he's approached by a college student, Holly Cantrell (Anna Friel), who believes his theories could be right after showing him proof via a fossil of a cigarette lighter, and a crystal that gives off tachyon energy. After building an amplifier for it, they head for a cave that gives off the same energy. Joined by Will Stanton (Danny McBride), the gift shop owner where the cave is located, the three venture in and discover a time warp which they fall into. Winding up in the alternate world where objects of various cultures and periods litter the land and populated by primate-like beings (such as their friend, Cha-ka), dinosaurs and lizard people. It's the find of a century! But can the group survive the world's dangers and more importantly, find a way back to their world.
The film is more comedic and slapsticky than the series, but also includes drug-use sequences and plenty of sexual humor, making the marketing campaign's partial targeting of children highly confusing. It's more a parody (described as such by Ferrell himself) than actually bearing any relation to the series.
Land of the Lost provides examples of:
- Action Dress Rip: Holly, after they arrive in the jungle, rips her pant legs off and turns them into short shorts.
- Adaptational Heroism: The Zarn is a good guy in the movie and was murdered by Enik while giving a warning against him.
- Adaptational Villainy: Enik in the show, while a bit of a jerk, was one of the Marshalls' allies. The same can't be said for his incarnation in the movie, who wants to Take Over the World.
- Advertising by Association: When the film came out in 2009, Universal Studios released the 1970 movie adaptation of H.R. Pufnstuf, on DVD, which contained a blurb on top of the front cover stating, "From the Producers of Land of the Lost" (Even though Sid & Marty Krofft completely created both series).
- Alien Sky: The Land has three moons.
- Animal Nemesis: Grumpy becomes this to Marshall after he insults the dinosaur's "walnut-sized brain".
- Artistic License Biology:
- How Marshall escapes after being eaten by Grumpy.
- There's also Marshall dumping hadrosaur urine on himself. Dinosaurs are reptiles, which do not urinate.
- Berserk Button: Marshall learns this the hard way after saying Grumpy has a "walnut-sized brain".
- Better Than a Bare Bulb: The movie has a lot of Lampshade Hanging, played for laughs.
- Book-Ends: Marshall's confrontational Today Show appearances with interviewer Matt Lauer.
- Chekhov's Gun: Two major ones — the fossil of a lighter is a perfect fit for Marshall's lighter, which he will drop later in the movie. The tachyon crystal Holly's wearing also becomes important.
- Cloudcuckoolander: Rick Marshall is a serious hardcase, though all three main characters qualify.
- Comedic Sociopathy: Some moments of in the movie rely on this. When an ice-cream vendor end up on The Land and is attacked by dromaeosaurs, our heroes just watch (and film), not showing the slightest bit of empathy. Likewise, when Rick is drained of blood by a giant mosquito, his companions just stare, never making a move to help him.
- Composite Character: Enik is one of the original Enik and the Sleestak Shung from the 1991 series, fulfilling the latters role as the primary antagonist with plans of domination.
- Dressing as the Enemy: Done by Marshall and Will with molted Sleestak skins. It's not as Squicky as it sounds, though.
- Dumb Dinos: Parodied. When a Tyrannosaurus rex attacks the protagonists, but they outwit it by crossing a log bridge, Marshall notes as it walks away that it only has a brain the size of a walnut. The T. rex takes it as a personal insult and attacks the protagonists again. Later it drops a gigantic walnut in front of the cave where the protagonists are hiding, just to prove a point. Seeing as real tyrannosaurs actually did not have brains the size of walnuts, he's right to be offended.
- Giant Enemy Crab: A giant crab appears during one scene in which it tries to attack the protagonists while they are stoned. However, it is killed by a geyser and is then eaten by the protagonists instead.
- Flanderization: The Sleestaks are little better than shambling zombies in the film while in the series they were slow-moving and technologically primitive but still had a society and used tools such as arrows.
- It Can Think: Grumpy doesn't take well to having his brain compared to a walnut. He even dumps a giant walnut outside their cave, just to prove a point.Stanton: Yep, this is definitely between him and you...
- Jerkass: Rick Marshall — not that his companions are much better. The only time they show any kind of camaraderie is when they're stoned out of their minds.
- Only Sane Man: Holly to an extent, though she appears at times to not utilize the sense she has been bestowed with.
- Plot Hole: It's hard to believe that some of the things that obviously went missing from the present weren't missed by anyone.
- Tears can happen at any point in space and time. The Golden Gate Bridge probably will be missed when it goes missing some time in the future (The 1930's ocean liner is a bigger question.)
- Proportionately Ponderous Parasites: giant blood sucking insects that swell greatly when drinking blood.
- Swallowed Whole: Doctor Marshall is eaten by Grumpy (briefly).
- Take That!: "Matt Lauer can suck it!"
- Tempting Fate: Dr. Marshall does it so often that it's lampshaded.
- Super-Persistent Predator: Grumpy the T. rex. Very slightly justified in that Marshall dumped urine of an herbivorous dinosaur on himself, thinking it would camouflage him. Doesn't explain why the T. rex was chasing them so much earlier in the movie, though. That was just... spite.Stanton: He's looking at you.
Marshall: He's looking at all of us!
Stanton: No... he's looking at you!
- Tyrannosaurus rex: Grumpy, the Animal Nemesis of Marshall, is a T. rex.
- Urine Trouble: At one point, Marshall dumps dinosaur urine on himself to disguise his scent.