"Unveiling the Astonishing Secrets of a 500-Million-Year-Old Marine Invertebrate Fossil"

Researchers have discovered a 500-million-year-old fossil of a tunicate, a strange marine invertebrate, shedding light on the ancestral lifestyle and evolutionary origins of these creatures. The fossil, named Megasiphon thylakos, reveals that ancestral tunicates were stationary, filter-feeding adults that likely underwent metamorphosis from a tadpole-like larva. Tunicates are the closest relatives of vertebrates, making their study crucial for understanding our own evolutionary origins. M. thylakos is the oldest definitive tunicate fossil with soft tissue preservation, providing valuable insights into the anatomy and early evolutionary history of these enigmatic creatures. The discovery was made in the middle Cambrian Marjum Formation in Utah, which has the potential to reveal more secrets about ancient animal groups.