Run Dino Run

The dinosaurs are getting smarter.

The people are getting stupider.

A lot stupider.

But really, what did you expect? This is “Jurassic Park III,” not Henry James, and after two previous films detailing the unstoppable savagery of what grumpy paleontologist Dr. Alan Grant calls “genetically engineered theme park monsters,” who with even a trace of sense would wander anywhere in their vicinity?

As if getting themselves onto the restricted Isla Sorna off Costa Rica wasn’t doltish enough, these new Jurassic Parkers yell when they should be quiet and move when they should be still. They wander into lairs, steal eggs and act so obtusely that when one of them says, “You have to believe me, this was a stupid decision,” no one will care to object.

Thank heavens for the dinosaurs, like the massive T. rex and our old friends the raptors, which Dr. Grant has discovered are not only “smarter than we thought” but also “socially sophisticated.” We don’t exactly see them air-kissing and eating peas with a knife, but that doesn’t mean they couldn’t if they had to.

New beasts even fiercer than these make their film debut as well. There’s the predatory spinosaurus, so enormous and powerful that it uses an airplane fuselage as a hacky sack. And the flying pteranodon, strong enough to carry a human in its claws and no less impressive for being, well, imaginary. The sheer physical presence of these creatures is much more believable and convincing than what can be generously characterized as the film’s plot.

As written by well-regarded newcomer Peter Buchman and the sharp “Election” team of Alexander Payne & Jim Taylor, “Jurassic III” has more amusing lines than you might be expecting. But it can’t escape its obvious Buck-Rogers-in-the-21st-century story line, can’t stop being the kind of film that, when someone says “no force on heaven or earth will get me on that island,” you know he’ll be on the ground inside of 10 minutes.

That someone is our Dr. Grant, back on screen after an eight-year hiatus and played by veteran Sam Neill with an appealing irritated geniality. With his beautiful colleague Ellie (a cameo for Laura Dern) now a happily married woman, he makes do with the handsome Billy (Alessandro Nivola) for his assistant.

It’s Billy, in fact, who pushes for the doctor to meet with Paul Kirby of Kirby Enterprises (William H. Macy) and his wife, Amanda (Tea Leoni). They say they’re adventure travel junkies who want to fly over Isla Sorna for their anniversary. Dr. Grant may know a lot about bones, but a great judge of people he’s not, and the flight is on.

Once the group lands on the island (did you really think it wouldn’t?), all kinds of paper-thin shenanigans transpire. Because encounters with the more predatory dinosaurs are distinctly one-sided --they chase, humans flee like it was a sequel to “Run Lola Run”--it’s a tribute to the action skills of director Joe Johnston (“Jumanji” is the relevant credit) that this film is as brisk and involving as it is.

And don’t forget those dinosaurs (as if). Once again, we’re the beneficiaries of state-of-the-art special effects of the computer-generated and animatronic variety, combined with physical stunts supervised by Michael Lantieri.

Jim Mitchell oversaw the ILM visual effects team, which did an exceptional job with herds of moving beasts, as well as with the immense and lordly brachiosaurus. And gifted veteran Stan Winston built remarkable models, such as the 44-foot, 13-ton spinosaurus replica.

Some of the film’s creatures, such as the flying pteranodons, are noticeably chilling, while the raptors, fierce as they can be, have a tendency to occasionally look like demented chickens on steroids. But it matters not. Humans may be stupid and fragile, but dinosaurs, dinosaurs are forever.

‘Jurassic Park III’

Sam Neill: Dr. Alan Grant

William H. Macy: Paul Kirby

Tea Leoni: Amanda Kirby

Alessandro Nivola: Billy Brennan

Trevor Morgan: Eric Kirby

Michael Jeter: Udesky

Laura Dern: Ellie

Universal Pictures presents an Amblin Entertainment production, released by Universal Pictures. Director Joe Johnston. Producers Kathleen Kennedy, Larry Franco. Executive producer Steven Spielberg. Screenplay by Peter Buchman and Alexander Payne & Jim Taylor. Cinematographer Shelly Johnson. Editor Robert Dalva. Costume designer Betsy Cox. Music Don Davis. Original themes John Williams. Production designer Ed Verreaux. Art director Doug Meerdink. Set decorator Kate Sullivan. Running time: 1 hour, 32 minutes.

In general release.

MPAA rating: PG-13, for intense sci-fi terror and violence. Times guidelines: frightening scenes of a child in peril, but overall the action is more suggested than graphic.