Patzer

When the Neanderthal is scared by the woman wearing a face mask and jumps into a bush, he is wearing big white shorts under his loin cloth.

When Bart chases after Julio in the storm, it alternates between a clear day and night time. It is not a "day for night" shot, it was obviously shot on a sunny day.

When the musicians are playing the steel pan drums, a guy wearing an orange shirt at the bar moves to the beat as the waitress serves Bart and Betty at the table. The scene immediately cuts to another angle at the table and the guy at the bar has stopped (it was just another angle of the same scene, not another action.)

When the power goes out in the cantina (with no backup), everyone is in the dark with only a few candles and lanterns for illumination; but shortly thereafter, when they evacuate the place, the normal lights have come back on: which no one mentions.

In the movie it states that the two dinosaurs are from about a million years ago, and that the Neanderthal man is also from a million years ago (i.e. the same time period). In reality the last of the dinosaurs went extinct around 65 million years ago while the Neanderthals existed between 400,000 to 40,000 years ago. The same huge anachronistic mistake (dinosaurs and cave men existing together a million years ago) was made in the 1966 movie 'One Million Years B.C.' staring Raquel Welch.

The two Marx dinosaur toys that Julio says he got from sending in box-tops were never giveaways with any product. They were only sold in stores, a part of a set of Dinosaur toys by Marx.

Only a fuse was inserted into the dynamite, no blasting cap. The dynamite would not have gone off without a blasting cap.

When the caveman is found on the beach by Hacker, he is frozen solid. Yet less than an hour or two later he is fully thawed and alive. It would take at least a day to thaw completely even in the tropical climate.

Correction: He is not completely frozen. He's been in the water and wet conditions for quite some time, which is a quick way to thaw meat. His joints are stiff from being in that position for eons.

Obvious stunt double as Julio runs away from cantina. Actor Alan Roberts is much shorter and smaller in stature.

When the caveman hears the ham radio screech and starts to swing his ax at it, there is no soldering gun on the table left of the radio. When the ax actually hits the radio, the soldering gun magically appears.

When the boy and caveman meet in the kitchen, the oven changes to a refrigerator when the boy looks for food.

Mike Hacker (apparently a Spanish-speaker from his accent) calls Chica his "little tamale". The correct Spanish singular is "tamal"; "tamale" is an incorrect Anglophone singular made from the plural "tamales".