Talking dinosaurs are almost never a good idea. Even the makers of "The Flintstones" figured that one out.

The Cretaceous-period inhabitants never shut up in "Walking With Dino­saurs," a misguided 3-D dinosaur romp created by BBC Earth. They yammer on and on with their poop jokes and romantic missteps until cynical parents in the audience start hoping for an asteroid strike. A tight 87-minute running time is small consolation.

The decision to anthropomorphize the main characters ruins what should have been a nice little prehistoric travelogue. After a short present-day framing sequence, viewers are sent back to 70 million B.C., where a herd of Pachyrhinosaurs embark on a danger-filled migration, hunted by a pack of carnivorous Gorgosaurs.

‘WALKING WITH DINOSAURS’ Rated: PG Opens today

The scene is set scientifically, with a short introduction to the species of the time and the fragile state of life. It’s just 4 million years before the mass extinction event (so close …), and the dinosaurs looked and behaved in a way that’s slightly less alien than their Jurassic forefathers. There’s potential for educational value here.

Instead, they start talking. A runt of the Pachyrhinosaur litter named Pachi (Justin Long) provides much of the comic relief, and his walnut-size brain is reflected in the writing. Pachi is dumped upon by excrement in the first 10 minutes of his life, and later talks like a preteen who is texting his lines. ("Worst. Migration. Ever," he mutters at one point.) A mating ritual with a female named Juniper plunges the script to new depths, with odd parallels to the love triangle in "The Karate Kid."

It’s hard to imagine that BBC Earth scientists wanted to make "Cretaceous Period 90210," so let’s assume the misguided dialogue decisions came from the top. In any case, "Walking With Dinosaurs" doesn’t give kids enough credit.

No doubt animated dinosaurs would have been enough to keep the children in their seats. Projecting human feelings on herd animals just adds confusion — especially later in the film, when the juxtaposition of human emotions with the pack’s alpha male ascension rules makes the Pachyrhinosaurs seem like a brainwashed cult.

The movie is well paced, with a diverse array of obstacles for the herd to overcome. The cinematography and use of 3-D is better than average; a prehistoric bird (also talking) provides an excuse for sweeping overhead views.

And to the credit of the filmmakers, the dinosaurs’ mouths don’t move when they talk. Apparently, they’re communicating telepathically. They should cut all the dialogue for the DVD, and add a few lines of Sam Elliott’s narration to keep the story straight. The resulting film would be easy to recommend.