The dinosaurs of “Terra Nova” have been put out to pasture.

After weeks of deliberation, Fox suits were unable to figure out how to evolve the befuddled, money-gobbling, time-traveling dino-drama into anything that could survive on its prime-time lineup. So they’ve canceled it.

As word got out, TV critic began calling out to TV critic, like mastodons bellowing across the primeval woodlands. It is the end of ambitious TV, they hollered. Cross your fingers that some other network picks it up, they yowled.

Back in January, after its first short season had aired (and averaged a middling 8 million viewers — including 3 million in the 18- to 49-year-old age bracket that the network sells to advertisers), Fox programming chief Kevin Reilly said noncommittally that “Terra Nova” “looked fantastic” but had been “hunting” creatively all season.

Reilly insisted that the show — which is produced by the Fox network’s studio cousin, 20th Century Fox TV — had made money for the company, thanks to ancillary markets such as overseas sales. He added that “if we had more holes in our network, we’d be thrilled to lock that right in.”

He noted that the network would soon have to make a decision on the show’s future, given the longer lead time needed to produce all its special effects.

In the end, special effects killed “Terra Nova,” sources say. After hearing the producers’ plans for next season, network execs still weren’t ready to commit to another round of the costly drama, which had not found its voice.

Speaking of time travel, it was way back in May 2010 that Fox execs first announced they would air a new “epic family adventure” set in 2149 but featuring dinosaurs, which could only mean — Steven Spielberg!

“Terra Nova” would follow an ordinary family living in a future in which Earth is overpopulated and horribly polluted — unlike today. The family members would join a band of settlers that travels in time to prehistoric Earth to fix problems that cropped up in the future — though the runaway cost of producing dino-dramas in the year 2010 was not on the list. The “Terra Nova” pilot alone cost upward of $20 million, according to press reports.

But by August, Fox execs conceded that things hadn’t gone as expected and that the network would instead air the two-hour pilot of its highly hyped orgy of special effects right after the final performance night of “American Idol” in May — after which it would launch the series in fall 2011.

“We got into it knowing it was going to be ambitious — knowing that we had enormous . . . groundbreaking digital effects we were bringing to it,” Reilly said back then.

“We had to create an entire world and mythology. But frankly, even locking in a location has had a unique set of challenges. . . . [blah, blah, blah] . . . It really became apparent, to do this show right, we were going to need the time. So we decided to make a virtue of out of it, slow it down. . . . [blah, blah, blah] . . . The two advantages of doing the spring [sneak peek] are [blah, blah, blah].”

But when May rolled around, Fox had scrubbed “Terra Nova” from its dance card and announced that it now intended to simply launch the show in fall 2011 — one year after the network began promising the series to America.

“ ‘Terra Nova’ is one of the most ambitious television series ever produced,” Reilly said that time.

“The cutting-edge visual effects used to create the world of ‘Terra Nova,’ which is of massive scope and scale, require more time to be realized,” Reilly added.

The night “Terra Nova” finally opened, only 9.2 million people tuned in.

With Fox having canceled “House” — which will end after this season — this week’s “Terra Nova” news opens up a second hour on the network’s prime-time slate.

Next up for consideration: J.J. Abrams’s spooky new time-traveling prison drama, “Alcatraz” — two episodes of which aired Monday and got trounced by NBC’s “The Voice,” ABC’s “The Bachelor” and even fell behind CBS’s comedy reruns.

Looks as if Fox could wind up with those “more holes” on its schedule thanReilly hoped for.