Elli refers to the fossil as "coming from a reptile, like a frog." Frogs are amphibians, not reptiles.
Elli says that the fossil had "never been found in this hemisphere" and goes on to say that it has been found in China and the Amazon. As the movie is set in North America, her statement had to be false. China is in the Northern Hemisphere and the Amazon is in the Western Hemisphere, which are the two hemispheres occupied by North America.
As Kelly catches a fish early in the movie he winds his reel repeatedly, but the bobber on the fishing line never moves.
At minute 58:00 Elli stumbles and finds what is later identified as a skull. The skull however still has an intact eyeball in it. The eyeball being soft tissue would not survive whatever process turned a human head into a skull.
At minute 1:05:00 young Kelly Jr tells his dad "the logger stole all your guns, at which point his dad reaches into a full gun cabinet and takes out a rifle.