What is cast fossil?

Cast fossils are formed when an organism's remains are buried and compressed by sediment. Over time, the organic material decomposes and leaves a void in the rock, creating a mold. This mold can then be filled by minerals, forming a cast that replicates the shape of the original organism. Cast fossils can provide important information about the physical characteristics of ancient organisms, such as their size, shape, and texture. They are particularly useful for studying organisms with hard body parts, such as shells or bones. Cast fossils are often found in sedimentary rocks, such as sandstone or limestone, and can be billions of years old. They are an important source of information for paleontologists and help us understand the evolution of life on Earth.