I wish I had seen it in 3-D. It was hilarious. Sid and Mother Dinosaur echoed Donkey and Dragon in Shrek although no long term relationship was going to happen here. The flying sequence involving a flock of pterosaurs was outstanding. The aerial flight sequences of standard movies had nothing on this one.
The story begins with the impending birth of Manny and Ellie's bundle of joy. Sid and Diego are feeling left out and lonely, so Diego decides to take off for the life of a bachelor while Sid manages to become the surrogate parent to a trio of eggs, that hatch out little dinosaurs. Mother Dinosaur comes looking for her offspring and takes off with them, and Sid, to a veritable dinosaur haven under the ice. The rest come looking for Sid and we are off to the races and the real story. Once again the value of relationships is stressed as the 'herd' commences on their adventure to find Sid. And what an adventure! We meet the crazed weasel Buck (Simon Pegg) (who sounds Australian to me) who becomes the unlikely leader, with Crash and Eddie worshipping the ground he walks on. Buck lost an eye to the king of the dinosaur land, which he has named Rudy. Rudy hasn't forgotten Buck but you can't keep a good weasel down when he's in the middle of a death defying struggle. Whether he is piloting a pterosaur for the first time or swinging through the vines a la Tarzan, Buck is a character that can't be held back.
Children of a certain age will surely appreciate Crash and Eddie, their surrogates on film, most especially in a scene where noxious gases result in high pitched voices and the equivalent behavior of folks on nitrous oxide (laughing gas).
If you need a few belly laughs, this movie will make them happen.