Hyolitha is a class of extinct marine animals that were abundant during the Paleozoic era. The term Hyolitha comes from the Greek word "hyle" (meaning wood) and "lithos" (meaning stone) because their fossilized remains looked like little wooden pegs. In modern times, scientists have come up with several synonyms for Hyolitha, such as the Phylum Hyolithozoa or the Class Hyolithida. However, these terms are not commonly used in scientific literature, and Hyolitha remains the most popular name for this fascinating group of creatures. With their cone-shaped shells and tentacle-like protrusions, Hyolitha played an important role in the ecosystem of early oceans, and studying their fossils can give us valuable insights into how life evolved on our planet.