Continuity mistake: When Indominous Rex has the gyrosphere in its mouth and is smashing it, the seats are facing up. When the passengers release their safety belts and fall to the ground, they are facing down. (00:59:20)
Continuity mistake: When the movie begins, a group of kids are watching a documentary. The employee holding the iPad lowers his right arm, then it's raised again in the following shot.
Continuity mistake: When running towards the Pteradons, Claire is with a group of ACU units. Camera changes and she's not in shot. In the reverse angle, she does run to the side, but even from the front angle she should have been visible. (01:22:00)
Continuity mistake: When the boys enter the old visitors centre, they open both doors and leave them open. When Owen and Claire come out through the doors, one of them is closed. (01:08:00 - 01:14:45)
Continuity mistake: When the ACU finds the I-Rex tracker, the way it's held between the first shot of it and the live feed is different. (00:45:45)
Continuity mistake: When the big flying bird comes down, its beak is pointing at one of the brothers in one shot and at the other in a different shot. (01:22:40)
Answer: And what about just digging for bones for the Mosasaurus? I think this was said somewhere-although I can't remember where so apologies if I'm wrong-but I think Dr. Wu mentioned something about it, so I'm sure they could've gotten DNA WITHOUT getting the blood from a mosquito. It sounds possible in my opinion.