Question

Compare the horseshoe crab that lives today with the fossil that is millions of years old. What kind of habitat do you think its fossilized ancestor lived in? Explain your answer.

Answer 1

Answer: Horseshoe crab fossils have been estimated to be 445 million years old. They co-evolved with other primitive arthropods called trilobites, a long-extinct close relative of the horseshoe crab, in the shallow seas of the Paleozoic Era (540-248 million years ago).