Which term refers to a hollow area in sediment shaped like an organism?

Which term refers to a hollow area in sediment shaped like an organism?

• A. Cast
• B. Petrified Fossils
• C. Mold
• D. Extinct

Answer: (C)

Think of how fossils form when an organism leaves an impression in sediment. The hollow space that mirrors the organism’s outer shape is a mold. It captures the negative image of what was there. If minerals later fill that hollow and harden, a cast forms, which is a positive replica of the organism’s shape. Petrified fossils involve the original material being replaced by minerals, not just a hollow impression, and extinct simply describes a species that no longer exists. So the hollow impression shaped like the organism is the mold.

Think of how fossils form when an organism leaves an impression in sediment. The hollow space that mirrors the organism’s outer shape is a mold. It captures the negative image of what was there. If minerals later fill that hollow and harden, a cast forms, which is a positive replica of the organism’s shape. Petrified fossils involve the original material being replaced by minerals, not just a hollow impression, and extinct simply describes a species that no longer exists. So the hollow impression shaped like the organism is the mold.