Swimming jellyfish, dating back 505 million years, have been astonishingly unearthed in the Canadian Rockies’ renowned Burgess Shale fossil site. The fossils belong to a previously unknown jellyfish species, Burgessomedusa phasmiformis, providing a glimpse into the advanced evolution of these creatures during ancient times. Despite being composed of 95% water, these soft-bodied animals have been remarkably preserved, with the fossils measuring approximately 8 inches (20 centimeters) in length. The findings, detailed in the journal Proceedings of the Royal Society B, offer a fascinating insight into the evolution of these ancient creatures.

Jellyfish, classified as medusozoans, possess umbrella-shaped bodies and stinging tentacles. They belong to the Cnidaria group, which includes some of the oldest animal species on Earth, such as corals and sea anemones. The discovery of Burgessomedusa phasmiformis fossils at the site indicates the early existence of large, bell-shaped jellyfish that could swim freely more than 500 million years ago. The Burgess Shale, where the fossils were found, is a treasure trove of well-preserved specimens, including soft-bodied animals and intricate details of their internal anatomy. These fossils provide valuable insights into the ancient marine ecosystem and how various species coexisted. While the origins of free-swimming jellyfish have been challenging to trace, these newly discovered fossils shed light on their evolutionary history. Burgessomedusa phasmiformis, with its distinct features like 90 finger-like tentacles for catching prey, likely played a significant role in the ancient marine food chain. The discovery adds a remarkable lineage to the Burgess Shale’s collection of preserved species, contributing to our understanding of Earth’s evolutionary journey.