These are trying times for network programming czars, which helps explain why ABC Entertainment topper Robert Iger is looking for salvation in prehistoric beasts. He and the network have bet tens of millions of dollars that their new live-action sitcom, “Dinosaurs,” will become the gargantuan hit-that-ate-the-competition, boosting ABC to a first-place spot in next fall’s primetime race.

“I hope this doesn’t turn out to be our ‘Heaven’s Gate,’ “says Iger. “This may be the biggest effort we ever put behind a series monetarily.”

ABC, according to Iger, is paying an “above average” licensing fee for the show. In addition, the net has spent an astounding amount of publicity dollars: “If you costed out all the commercial time on our air, plus spots on cable and other media, you might be talking about a $25 million campaign,” says Iger.

If the show flops, it’s not only Iger who has plenty to lose. “Dinosaurs” co-producers the Walt Disney Co. and Jim Henson Prods. reportedly have invested $2.5 million in development costs for the show. Individual episodes are running as high as $1.5 million, more than twice the amount for an average sitcom, driven skyward by the complex lifesize Henson puppets. (“Dinosaurs” reportedly is being produced at a deficit that may be as high as $800,000 per episode, which will only be recouped if the show makes it into syndication.)

Also, while the show’s producers claim it’s not a factor, the acrimonious legal battle between the two companies over licensing rights to Henson’s Muppet characters can’t be helping matters any.

“Remember ‘Moonlighting’?” jokes “Dinosaurs” executive producer Michael Jacobs, comparing his reptilian sitcom to the ABC series plagued with production problems, star egos and cost overruns.

ABC badly needs its prehistoric gambit to work. If successful, the web would have an 8 p.m. hit to anchor its Tuesday or Wednesday night lineup next fall, making the difference between first and last place next season. Finding a breakout 8 p.m. hit is the web programmer’s Holy Grail, something that has proved elusive since last season’s “America’s Funniest Home Videos.”

“It’s so hard to find that 8 p.m. hit,” says Iger. “There’s so little to choose from…. There’s this feeling that it’s some kind of mindless enterprise. That’s why when we got the ‘Dinosaurs’ script and it was so strong we rallied the troops and decided to go all out.”

The ABC hype machinery has been both masterful and relentless. The first “Dinosaurs” teaser appeared on the Academy Awards, followed by promos in all the web’s primetime shows up to the week of its April 26 premiere.

The day of the premiere, virtually every ABC entertainment show had some “Dinosaurs” reference, ranging from a character on an ABC soap wearing a “Dinosaurs” t-shirt to “Match Game” celebrity panelist Sally Struthers displaying a photo of “Earl Sinclair,” the show’s Archie Bunkeresque “megalosaurus” dad.

To insure maximum audience sampling for “Dinosaurs,” the web hammocked it between “Full House” and “Family Matters,” ABC’s Friday night blockbusters. Starting with the second episode May 3, the web will “double pump” at least two of the six shows it will air in the coming weeks, running it a second time after “America’s Funniest Home Videos.” The web will save the remaining episodes of its 13-show order for next fall.

“I don’t know how it will ever live up to the hype,” says a Henson executive.

“Certainly there’s some trepidation that we’ve created an expectation level we won’t be able to sustain,” says Iger. “But we needed something to create some spark to take us into next season.”

And if “Dinosaurs” doesn’t have legs and is extinct before next fall?

“I started out in this business as a weatherman on a station in upstate New York,” says Iger. “And I’ve asked [CapCities/ABC prez and CEO] Dan Burke that if ‘Dinosaurs’ doesn’t work out, he could make a slot for me in at the company’s station in Raleigh/Durham.”