posted by Anonymous .
Very few fossils of jellyfish or their close relatives have been found. This makes it hard to trace the evolutionary history of jellyfish using the fossil record. What explains this?
A. Jellyfish fossils are buried deep under the ocean floor, not in land areas where scientists look for fossils.
B. Jellyfish have soft bodies that decay completely before fossilization can occur.
C. Jellyfish are a relatively new species in the history of living things on Earth and do not have ancient ancestors.
D. Jellyfish fossils are likely more fragile than other types of fossils and so they degrade before they can be examined.