Factual error: At the start of the movie you can see the Flag of Great Britain on Solomon's ship. The film is set in 1600 and the Union flag didn't exist until 1606.
Factual error: At the start in 1989, when Mike is dancing with the cheerleaders and also just before he goes after Scarlet, in close-ups of the crowd cheering there is a man (with a white baseball cap) wearing a Paramore t-shirt. However, Paramore (a Grammy-nominated American pop rock band) formed in 2004. The style of t-shirt he is wearing is actually one of the officially licensed Paramore merchandise. (00:02:45)
Factual error: When Wolverine is being chased after the explosion of the barn, there's a Humvee chasing the motorcycle. The movie is supposed to take place in the late 70's - the Humvee started production in 1984 and started service in the late 80's.
Factual error: The sheriff mentions that they don't have a license plate on the front of their vehicle, but according to the aliens' map device, they're located in Michigan, where a front plate is not required.
Factual error: The alligator mentions wanting a Bananas Foster. This dessert was invented in 1951 but this movie takes place in 1926.
Factual error: Another problem with Speckles the star-nose mole. Star-nose moles live in "wet lowland areas" (Wikipedia) but in the film, Speckle's history is shown and his home used to be a field with undulated small hills.
Factual error: The "US Lead Destroyer" attacked by the megladon is the Iowa class battleship USS Missouri (BB63). (00:29:00 - 00:31:20)
Factual error: Despite the film building to a climax during a total solar eclipse, which requires a New Moon, the film constantly shows a Full Moon, which never changes phase over the weeks the film takes place.
Factual error: At the beginning Scrooge is seen signing Jacob Marley's death certificate in the year 1836. English Birth, Marriage & Death certificates didn't come into being until 1837.
Factual error: In the scenes on Mars, two spherical moons can be seen in the background. However, in reality, the moons of Mars (Phobos & Deimos) are not spherical. Also they are so small, that they would only appear as moving dots in the night sky, not spheres like Earth's moon.
Factual error: The lead song, "Lollipop," wasn't written until 1958, seven years beyond the chronological order of the movie.
Factual error: There is a poster of Shaun Cassidy hanging on Susie's bedroom door - not only was Sean Cassidy only 15 years old at the time, but he hadn't even had a hit single yet.
Suggested correction: If you're talking about the poster visible at the 16-minute mark, I'm pretty sure that is Shaun's half-brother David Cassidy who was at the height of his popularity in 1973.
It's definitely David Cassidy.