Revealing mistake: Throughout the movie closeups of Enik's eyes reflect the lights and set around him that aren't part of the movie. During the scene when he's talking to Dr. Marshall about how the crystal controls the sleestack, you can see the white ceiling of the soundstage and lights which instead should be the sky.
Continuity mistake: The fossil of the lighter shown at the beginning of the film does not match how the lighter is pushed by the T-Rex into the mud later on as the text is face up. Since the lighter was pushed INTO the mud - the resulting fossil would have been flat with the words reversed on it.
Other mistake: Due to the gait of the T-Rex, its head moves rather significantly when it walks as seen throughout the movie. However when it approaches Dr. Marshall with the laser in its teeth, the laser is steady and able to pinpoint a line up his head in a very steady manner which would not have been possible.
Continuity mistake: When the mosquito is sucking on Dr. Marshall's neck, it keeps changing positions from higher up on his shoulder to more towards the front between shots. This is clear by watching the legs of the bug going from in front of his shoulder to being over the strap even when his head isn't moving.
Continuity mistake: When the team lands on the pile of bones, there is some sort of yellow stuff holding it together. The pile is also flush up against the sides of the cave. When the Vines grab them and its a far away show, the yellow stuff disappears and is now a loose pile of bones that's no longer flush against the cave sides.