Corrected entry: Kate finds a Graboid fossil and explains that the rock is from the Precambrian era (which ran from about 4.5 billion years ago through about 500 million years ago), thus making them literally the oldest complex life-forms in the history of Earth. Cool idea, but it makes no sense. Life in the Precambrian era was mostly bacterial or simplistic organisms such as sea-sponges and jellyfish late in the era. Something like the Graboids just couldn't have existed, both because they're too complex to have existed in that time-frame and also (and more importantly) because there wouldn't be an adequate food source for them to thrive. Sure, maybe they could have existed during the time of dinosaurs, but that only started about 250 million years ago, way after the end of the Precambrian era.
Corrected entry: After killing a Graboid, Grady says, "That makes $300,000," meaning they only killed six, but they actually killed, including the most recent one, eleven.
Corrected entry: When Grady leaves the radio playing on the ground, a graboid eats it. The next day, when foolish Grady steps on the ground, he hears the radio playing in the graboid's mouth. Don't you think that from running non-stop for that period of time, the batteries would've died?
Corrected entry: In the scene where the graboid is pulling the truck, Grady tries to shoot the graboid to make it release the chain. Wouldn't it have been easier to shoot the chain?
Corrected entry: While the graboid is pulling the truck across country, look at the ground between the graboid and the truck and you will see tire tracks on the ground.
Corrected entry: In the scene where the monster is pulling the truck, the truck has a rifle on its gun rack. The rifle gets into the hands of Brady who is in the truck bed, then back into the gun rack a few scenes later while Brady is still in the bed.
Corrected entry: According to Kate, every time the walking graboids eat, they reproduce. If this is so, how come they didn't reproduce when they ate Pedro or Julio?