Title: Exceptionally Well-Preserved Fossils Reveal Oldest Swimming Jellyfish Species
Subtitle: Burgess Shale in Canada Unveils Prehistoric Jellyfish with 505m-Year-Old Fossils
By Nabiha Ahmed
In a groundbreaking discovery, scientists have identified the oldest species of swimming jellyfish ever recorded through fossils dating back 505 million years. Named Burgessomedusa phasmiformis, this newly unearthed species was found exceptionally well preserved in the renowned Burgess Shale region of Canada.
Resembling a large, swimming jellyfish with a bell-shaped body that reached heights of up to 20cm, Burgessomedusa phasmiformis boasted approximately 90 tentacles, enabling it to capture larger prey. Jellyfish belong to the medusozoans, a subgroup of cnidaria, which is the oldest group of animals ever known to exist.
Jellyfish fossils are exceedingly rare due to their composition, as they consist of 95% water and rapidly decay. However, the specimens discovered in the late 1980s and early 1990s in Burgess Shale were remarkably well preserved, offering a unique glimpse into the ancient past.
Dr. Jean-Bernard Caron, a curator of invertebrate palaeontology at the Royal Ontario Museum and co-author of the study published in the journal Proceedings of the Royal Society B, expressed awe at the discovery. He described the finding of such delicate animals preserved in the rock layers atop the mountains as a “wondrous discovery”.
To understand the evolutionary history of jellyfish, scientists have traditionally relied on microscopic fossilized larval stages and molecular studies from living jellyfish. Unearthing the Burgessomedusa phasmiformis sheds new light on their evolutionary lineage and reveals the complexity of the Cambrian food chain.
Joe Moysiuk, a palaeontology student at the University of Toronto and co-author of the study, explained that jellyfish fossils have been elusive in the Cambrian fossil record despite belonging to one of the earliest groups of animals. However, the discovery of Burgessomedusa phasmiformis leaves no doubt that jellyfish were actively swimming during that era.
The significance of the find extends beyond the realm of jellyfish. Caron remarked, “This incredible discovery adds yet another remarkable lineage of animals to the already impressive roster that the Burgess Shale has preserved, chronicling the evolution of life on Earth.”
The findings of this study challenge previous assumptions about the complexity of the Cambrian food chain and provide invaluable insights into the origin and diversification of jellyfish species. As researchers continue to unlock the mysteries of Burgess Shale, the ancient past of our planet becomes clearer, offering a window into the vast and diverse evolutionary journey of life on Earth.