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)
Revealing mistake: Dr. Shannon identifies the skeleton as being a middle-aged male, but the skull is female. A male skull has a more pronounced ridge over the eye orbits, a sloping forehead, a longer mastoid process, and the skull widens at the back, unlike a female's that is more parallel.
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 ★