Revealing mistake: At the end of the brachiosaurus scene, with the camera being high above the set already, one animal lowers its head to take yet another branch from Zoe's hands. Zoe holds nothing at the time and the dinosaur misses her entirely. (00:30:10)
Continuity mistake: After removing their rebreathers, they are again with them at 12:48, and then are sans the rebreathers and their jackets at 13:19.
Continuity mistake: Skye and Josh are swimming by the rocks with the geometric drawings. When they get out of the water they focus on Josh and it's sunny on both of them, and overcast when they focus on Skye, from shot to shot.
Chosen answer: Because that's where the rift led. They don't have a time-travel machine, capable of taking them wherever they please - all they have is a hole in time leading to one single time period.
Tailkinker ★