Ice Age 3: Dawn of the Dinosaurs (commonly known as Ice Age: Dawn of the Dinosaurs) is a 2009 computer-animated comedy adventure film and the third installment in the Ice Age franchise. It was produced by Blue Sky Studios and released by 20th Century Fox.
It was released in July 1, 2009 with a sneak preview shown nationwide at selected theaters on Father's Day in the USA. It is the first Ice Age movie to be released in digital 3D and is by far the most popular movie in the Ice Age franchise so far.
Despite receiving mixed reviews from critics, the film was warmly-received by the general public. The film was also a massive blockbuster success, grossing $886 million worldwide against it's $90 million budget. It is the third highest-grossing film of 2009 (behind Avatar and Harry Potter and the Half-Blood Prince), the highest-grossing animated film of 2009, and the 14th highest-grossing animated film of all time.
After the events of Ice Age: The Meltdown, life begins to change for Manny and his friends: Scrat is still on the hunt to hold onto his beloved acorn, while finding a possible romance in a female saber-toothed squirrel named Scratte and his new wife Ellie are expecting a baby, which leaves Manny anxious to ensure that everything is perfect for when his baby arrives. Diego is fed up with being treated like a house-cat and ponders the notion that he is becoming too laid-back. He eventually leaves the herd. Sid begins to wish for a family of his own, and so steals some dinosaur eggs which leads to Sid ending up in an underground world where dinosaurs roam free, and where his herd must rescue him, while dodging dinosaurs and facing danger left and right, and meeting up with a weasel known as Buck who hunts dinosaurs intently and has a mammal chauvinism.
Sid's New Family
One year after the events of Ice Age: The Meltdown, Ellie and Manny are expecting their first child, and Manny is obsessed with making life perfect and safe for the family. He is shown bringing a shell full of water to Ellie believing that she is giving birth, although this is just a false alarm. At the same time, Diego finds himself unable to catch an antelope he has been stalking. The antelope starts to taunt him. Believing that he is losing his predatory as a tiger, he decides to leave the herd after a talk with Manny. Sid grows jealous of Manny and Ellie and “adopts” three apparently abandoned eggs that he finds in an icy underground cavern. Manny tells him to put them back, but Sid instead looks after the eggs, which hatch into baby Tyrannosaurus the next morning.
The Journey Begins
Although Sid tries his best to raise the three dinosaurs, their rambunctious behavior scares away all the other animals’ young and ruins a playground Manny built for Ellie’s baby. The mother dinosaur soon returns and carries both Sid and her youth underground, with Diego in pursuit. Manny, Ellie, Crash, and Eddie follow as well and discover that the icy cavern leads to a vast jungle populated by dinosaurs thought to be extinct. Here, an Ankylosaurus threatens the herd despite Diego’s efforts to fend it off. Ellie gets a Brachiosaurus to lean down at the ledge and they slide down the dinosaurs neck. On the ground, they are saved from a further crowd of angry dinosaurs (including Kentrosaurus, Brachiosaurus, Iguanodon, and Pachycephalosaurus) by a one-eyed, slightly crazed weasel named Buckminster, or Buck.
Buck has been living in this jungle for some time and chasing Rudy (the younger brother of the mother dinosaur and the dinosaur world's terrorist), intending to avenge the eye he lost to it. He agrees to lead the herd through the jungle’s perils to Lava Falls, where “Momma” has taken Sid and her babies. Soon Manny and Diego are captured by a carnivorous plant, but thanks to Buck, they are freed. In the meantime, Sid and the mother try to outdo each other in feeding the offspring; Sid loses this contest, but is soon welcomed into the family regardless. Suddenly, Momma hears a loud roar off in the distance and nudges her kids to go forward. This makes Sid wonder "What on Earth could be bigger than Momma?" After the group leaves you see Rudy's foot come down on one of Momma's footprints, which was about the size of Rudy's middle toe.
That night, Buck tells the story of how his eye was taken by Rudy, and was nearlly swallowed by him, but Buck launched himself out of his mouth, knocking one of his teeth out in the process, which he then proceeded to use as a weapon.That night, while the herd was resting Manny had a bad dream of Ellie all alone in a jungle and being killed by Rudy. After he wakes up, Ellie was still sleeping; however, she woke up, too, and Manny explains to her about his nightmare. Because Ellie was in the nightmare, she explains the most dangerous place in the world is bigger than her and Manny. Buck hears that if Manny was nicer to Sid, they wouldn't be searching for him. Buck says that Manny risked his own life and his unborn baby. That makes Manny a friend and a hero.
The next day, however, Rudy attacks Sid, who was knocked off of Momma's tail by a rock. Rudy proceeds to chase Sid to the shore of Lavafalls, where one of Rudy's feet cracks the rock that makes up the shore and the slab Sid is on begin to float off. Sid is relieved that he escaped Rudy, but then realizes that the lava leads to a fall.
The Final Battle
As the herd moves toward Lava Falls, Ellie goes into labor and a Guanlong pack strikes, causing a rock slide that separates her from Manny and Diego. Manny doubles back to protect her and Diego fends off further attacks, while Buck takes Crash and Eddie ahead to rescue Sid. Just as the sloth goes over the falls, the trio swoops in on a commandeered Roger and saves his life (after being chased by some Quetzalcoatlus). Manny reaches Ellie just as their baby is born, a girl they decide to name Peaches (the codeword they had chosen for Ellie to use if she went into labor during the trip). Sid is saddened at the fact that he never had a chance to say goodbye to "his" children as he is reunited with the herd.
Before they can exit the jungle, Rudy (who is revealed to be a giant albino Baryonyx that is this world’s biggest dinosaur) is hiding in the cave the group entered through; his rough, grey skin ressembling rock in the darkness. Buck is saying his goodbye's to the group when Rudy exhails, which moves bucks fur when he realizes that they are not alone. Buck draws him away from the herd by showing off his knife, being made from Rudy's tooth, and Rudy licks the scar that was left behind. Buck helps the others ensnare him briefly, but he escapes and resumes his onslaught. The herd is saved by the timely arrival of Momma, who charges at Rudy and knocks him off a cliff.
As she and her children wish Sid well, Buck – now without a purpose in life since Rudy is gone – decides to join the herd and live on the surface. However, a distant roar tells him that Rudy is still alive; he changes his mind and sends the herd home, he destroys the path to the underground jungle at the same time so that no one can go down there. Buck said goodbye to the herd and promises them that he'll see them again someday. Manny and Ellie welcome Peaches into their frozen world and admit that Sid did a good job looking after Momma's children. Diego decides to remain with the herd. Buck remains underground, foreshadowing his appearance in Collision Course.
In the end, Scrat, who had fallen in love with the female squirrel, decides to stay in the jungle down there with her. Unfortunately, Scrat's greed for his precious acorn overcomes his newfound romance with the female squirrel, and he ultimately chooses the acorn over her. The angry female squirrel and Scrat battle once more for the acorn, resulting in Scrat being repelled to the surface while the female squirrel is trapped in the jungle. The movie ends with Scrat celebrating with his acorn, however, once again, loses it, much to his frustration.