Having lost his edge and stamina in hunting down prey, Diego thinks it's time for him to move on, while Sid feels he's losing his unorthodox family and longs to have one of his own. When he ends up falling through a layer of ice down into a hidden cave, he "adopts" three eggs, unaware that they're about to hatch into baby T-Rexes.

Yet, rather than eat him, the three baby dinos (that are bigger than him) view Sid as their mother, a development that doesn't sit well with their real and significantly larger mom who carries them and Sid back into her underground tropical world where all manners of other dinosaurs exist.

Despite Ellie being near labor at any moment, she, Manny and Sid, along with possums Crash (voice of SEANN WILLIAM SCOTT) and Eddie (voice of JOSH PECK), set out on a rescue mission. Their unexpected guide into this prehistoric world is Buck (voice of SIMON PEGG), a one-eyed swashbuckling weasel who wants to get his revenge on an enormous T-Rex he's nicknamed Rudy.

While saber-toothed squirrel Scrat continues his obsession with getting his paws on the ever-elusive acorn and must contend with competition from female saber-toothed squirrel Scratte, the unlikely group of mammals set out to find and rescue Sid, all while trying to avoid the monstrous carnivore that would like to make lunch of all of them.

Yet, as much as children enjoy chatty critters, they really love dinosaurs, so it's something of a surprise that it took the filmmakers responsible for the "Ice Age" flicks three installments before they got around to including them. Granted, the first two films were, natch, set millions of years after their extinction. Even so, and save for various sorts of birds that mimic human speech, animals generally don't talk, so that sort of previous and continued artistic freedom allows for the addition of "thunder lizards" to the mix in "Ice Age: Dawn of the Dinosaurs."

Alas, their inclusion, as well as the addition of 3-D imagery (in select theaters, probably at a higher admission price) can't do much to lift this film out of the sort of mediocrity that started last time around (in 2006's "Ice Age: The Meltdown") and continues here.

Oddly enough, the filmmakers -- co-directors Carlos Saldanha and Michael Thurmeier, working from a screenplay by Michael Berg, Peter Ackerman, Mike Reiss and Yoni Brenner -- have made the dinos mute while just about everyone else (in mammal form) can't keep their yaps shut.

The result is that the dinosaurs are relegated to prop status, be that in the form of a trio of baby ones, their none-too-happy momma T-Rex, an even larger version of her, and a smattering of others, all of which mostly lack the sort of new infusion personality this sort of film needs.

The latter does arrive in the form of Buck, a swashbuckling, Captain Ahab type weasel who's fairly deranged in his quest to tangle with the biggest T-Rex in the land. As voiced by Simon Pegg, he's a breath of fresh air in what's otherwise a fairly stale environment where even the highlight of the past two films -- Scrat the saber-toothed squirrel and his "silent comedy" sort of quest for the ever-elusive acorn -- feels recycled and repetitive this time around.

Although there's seemingly more action in this outing (although, to be honest, I barely remember much of anything about the general plot let alone any sort of specific details regarding the first two flicks, a testament, I suppose to their general mediocrity), that material is more akin to viewing segments of a video game than complementing the story.

Save for some point of view chase material and simply adding depth to the overall proceedings, the 3-D doesn't add much either, and while the computer-generated visuals are (if memory serves me correctly) seemingly better than before, they're still not up to snuff with the best of what this genre can deliver.

Granted, they don't have to be if the story can take up the slack and keep us engaged and enamored with the characters. Sadly, there's little here to do that, and the pic clearly pales in comparison to the imaginative plots, characters and adventures that Pixar routinely kicks out, including in the recently released "Up."

Instead, this one plays much, much younger (although some of the humor might raise some parental eyebrows) and without any degree of sophistication. In the end, such children might enjoy their reunion with these characters and their related new adventures, but there's little here to engage adults, let alone make this any sort of classic that will endure the passage of time.

The addition of dinosaurs might have seemed like a good idea on paper, but that (and the 3-D) seems like something of a desperate ploy to keep this film series from heading toward extinction (or at least the inevitable and eventual straight to video route). Yet, while it will likely be highly profitable once again, these offerings are feeling ever more stale with each subsequent release.

Energetic at times along the lines of a video game but nothing more than superficially engaging as a storytelling experience, "Ice Age: Dawn of the Dinosaurs" wastes its newly added titular subjects and rates as just a 4 out of 10.