Continuity mistake: The telephone on Scrooge's desk briefly disappears after his maid delivers an invitation to the archaeological society ball. (00:19:05)
Continuity mistake: When Sam points his gun at Bugs at Fort Knox, he says "But I can't take any chances!" and throws away the gun. In the next shot, the gun is back in his hand again.
Continuity mistake: In the second scene where we first meet ranger Smith he is shuffling with some information pamphlets. When Ranger Jones yells his name he is startled and drops some of the pamphlets, but we can see that the last ones he put in were on their side. When the camera changes shots there appears to be some pamphlets sticking out. Then in the next shot they are gone. The pamphlets change locations between shots.
Revealing mistake: When Alex says they should go find the penguins, he says "To home" and Marty, Melman, Gloria and Julien place their hands on top of his hand. In the next shot it shows all of them together. But due to the position of Julien and his arm length, it would have been impossible for Julien to have his hand fully placed on Alex's hand. (00:05:05)
Continuity mistake: When the delegates assemble in the Great Hall, it is first shown that Canada is sitting to the left of Morocco. But shortly afterwards, Morocco is suddenly sitting to the left of Iceland, and Canada has mysteriously vanished.
Continuity mistake: When Speedy rushes out to take all the cheese in the trap that George and Benny have put out for him he is seen wearing a sombrero; however, for the rest of cartoon he is hatless, repeat, hatless.
Continuity mistake: When Petri fell into the tar pit, there were two dinosaur skeletons, one on each side. When Spike, Ducky and Littlefoot went to rescue him, the skeletons were gone.
Audio problem: The chairman talks to the mayor, and says that "no one supports you." When he says "supports", his lips look nothing like it.
Other mistake: In the first dining room scene, Courtney is reading, but her book is invisible.
Continuity mistake: When they jump in the pool, they drop the guitar. When they jump out their guitar is no longer in the pool.
Continuity mistake: In the scene when Mike is at the school door lab. When he swipes the access card the door swings out. But when the campus police try to get in it is blocked from the inside, indicating the door opens inwards.
Suggested correction: If you look carefully, you will see, that those are actually two different doors, which even have hinges on different sides. There's some space between them in the entrance to the lab, it can be seen just before Mike enters.
Other mistake: In the intro to the Pastoral Symphony, the narrator identifies the deity who cloaks the world with Night to be Morpheus, who is the Greek god of sleep and dreams. However, the character in the animation is fairly obviously female, with long hair, eye shadow, and lipstick. My theory is that the character was intended by the art team to be Nyx, the Greek goddess of Night. Night would be a more likely candidate to be making it nighttime across the world, while Morpheus would be more likely to put people to sleep or send them dreams.
Suggested correction: Without further evidence/proof, this theory remains just that. A theory.
Continuity mistake: When the Once-ler is drifting down the river in his bed, he puts his foot in the water, which makes the bed turn. When he puts his foot back onto the bed, it is dry and so is the bed sheet.
Other mistake: Duke is running through the city while dragging Max by his leash. A close-up shows Max being pulled between the bars of a metal fence, but the gap is much too small for Duke to have passed through.
Revealing mistake: After Chuck steps on the toy duck, he looks up to see the alien family and their house behind them. However, there is no reflection of this on his visor, just an empty field and the trees beyond.
Continuity mistake: In the carnivorous plant scene, Manny grabs the fruit (the bait), which is sitting in the middle of the plant. In the next few shots, the bait disappears and then is replaced with a bulb that housed the red and blue "wires".
Factual error: In the scene where the fireflies light the fireworks there is one problem: The chemical that creates light wouldn't ignite the wick on a firework.
Factual error: When Brendan Fraser comes out of the Louvre, the Eiffel Tower is right in front of it. The Louvre and the Eiffel Tower are miles away from each other.
Deliberate mistake: Manny refers to the pirate rabbit as the Easter Bunny, even though Easter never existed in prehistoric times. (00:33:55)
Suggested correction: And mammoths didn't hang out with sloths and smilodons either. It's creative license.
Factual error: During the plague when the fire and rocks are falling from the sky, they fall behind a statue of Rameses and are seen through its hollow eye holes. It makes for a great image, but that would mean that the statue's eyes were punched out like a mask, even though before they were just carved into the stone.