Plot hole: When George stops the machine for the first time, the candle burned down to about half of its size, which took according to his observations 98 minutes. But as the trip continues it takes seven hours for it to burn down completely. (00:25:45)
Plot hole: The morning of the final battle, the sun rises behind the mission, silhouetting a sentry. When the ending credits roll, the sun sets behind the mission.
Plot hole: In the arial shot of the plateau, it's obvious its just a mesa. It's not at all large enough to support such big animals like those dinosaurs, who would have to eat great amounts of food. All small animals would be hunted into extinction, and all of the trees would have been cleared out long ago. Plus, there would be no place for the dinosaurs to hide, so the team should have seen the monsters right away.
Plot hole: How did Glabrus know about Silesian pirates aiding the slave army's escape? He informed the senate of this and yet was not made aware of it at the time of his capture.
Plot hole: When the cop comes back after making the phone call, he's just missed Norman. He heads over to the office and calls out for Bates. He's in there around 45 seconds. Then he leaves and heads towards the big house. How can Norman be at the house ready to kill him in his mothers clothes, when he had no idea the cop was back and he would not have had time to get there from where he was, right at the far end of the cabins?
Suggested correction: Because Norman heard/saw him coming up the road. Norman hesitates before he goes into a cabin or behind one, it's not clear which. He has seen Arbogast's car before and recognizes it. He goes the back way between the two buildings of cabins (just like Vera miles does later when she goes to the house) and up to the house to put the dress/wig on and be ready for Arbogast when he gets to the top of the stairs.