Do you ever walk the beach, see a rock with holes in it and wonder how the rock got so holey? Pholadidae, also known as piddocks, are a marine mollusk that has a shell with a set of ridges or “teeth” which they use to grind away at clay or soft rock to create a tubular burrow. It will stay there for its entire eight-year lifespan, with only its siphon exposed to take in water that it filters for food. Although they didn't make an appearance in the movie, they have been around since the Jurassic period. I guess that's because the T-Rex is slightly more scary than a mollusk.