The earliest Egyptian pyramid was erected circa 2630 BC. The film doesn't show the Giza pyramids as completed, which may be an effort to satisfy both those who believe the Giza pyramids are relatively recent, and those who believe they are substantially older.
Several scenes show mammoths galloping. Mammoths were closely related to modern elephants, and couldn't gallop because of their physiology. At best, they could move at a fast trot, like elephants do. They were also never domesticated as pack animals.