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.
Revealing mistake: When Scrat removes the giant acorn in Scratlantis the city is immediately flooded. Everyone in the background is blown away by the sudden rush of water. However, both Scrat in the background and Scrat's host (slightly off-camera) in the foreground don't move and don't seem to be affected by extremely strong flow. (01:18:50)
Continuity mistake: When Scrat arrives at Scratlantis, it is shown that the acorn-shaped island is formed by 3 land masses lined up. However, when Scrat causes the island to sink, a full solid acorn-shaped island is shown sinking. (01:17:00 - 01:18:50)
Continuity mistake: When Sid and Manny are chasing the boat, Manny lifts up Sid and he is hit by a branch. However, in the next shot the branch is gone. (00:52:15)
Continuity mistake: Fleeing from the giant crab, Sid runs to the leading edge of the huge ice float. Two shots later, the camera displays the leading edge of the ice float as it begins to go downhill, but Sid isn't there anymore. (00:18:00)
Continuity mistake: In the shot when Granny talks about her dead pet and the young male sloth complains about it, the uncle sloth can not be seen between them, but instead appears between them in the following shot. (00:05:25)
Continuity mistake: When the pirates sing their shanty they throw sea stars at Sid on each side of him. In different shots, there are three on one side. (00:29:40 - 00:30:40)
Deliberate mistake: Some of those branches would definitely not have been able to support Peaches' weight. (00:04:00)
Other mistake: The way Sid interacts with the whale's blowhole is illogical in relation with the manner the water is being discharged. When viewing Sid up close, it is seen that the water stream is divided and outspread due to Sid's manner of blocking parts of the blowhole with his body. Despite that, when viewed further away the water stream is intact and traveling straight ahead. Once the water stream is seen doing just that, the following shot shows a boar getting hit by it as if it somehow hadn't already occurred, not only that, but the stream of water that was displayed in that shot was delimited, despite the water discharge never being paused and Sid never changing positions. When Sid starts rotating, delimited streams of water are seen traveling in various directions one at a time, when there should have been multiples at a time according to what is viewed when close to Sid. (01:07:05)
Continuity mistake: In the shots of Scrat getting flung away after tripping and then bouncing between the inner and outer core, the distances between the inner end of the outer core and the inner core are completely different. (00:02:10)
