Creative restoration of a group of Burgessomedusa phasmiformis swimming in the Cambrian sea. Credit: Reconstruction by Christian McCall © Christian McCall.
505-million-year-old swimming jellyfish from the Burgess Shale highlights variety in Cambrian community.
The Royal Ontario Museum (ROM) has actually revealed the discovery of the oldest recognized swimming jellyfish in the fossil record, the freshly called Burgessomedusa phasmiformis. The discovery was released in the journal Proceedings of the Royal Society B.
Jellyfish become part of the medusozoans, a group of animals producing medusae, and consists of contemporary animals like box jellies, hydroids, stalked jellyfish, and true jellyfish. Medusozoans are part of the ancient animal group called Cnidaria, which likewise contains corals and sea anemones.Burgessomedusa is a definitive indicator that big, swimming jellyfish with a standard bell-shaped body had actually already evolved over 500 million years back.
The Royal Ontario Museum (ROM) has revealed the discovery of the oldest known swimming jellyfish in the fossil record, the newly named Burgessomedusa phasmiformis. The discovery was released in the journal Proceedings of the Royal Society B.
Jellyfish are part of the medusozoans, a group of animals producing medusae, and includes present-day creatures animals box jellies, hydroids, stalked jellyfish, and true real. Burgessomedusa fossils are remarkably well protected at the Burgess Shale thinking about jellyfish are roughly 95% made up of water. Field images of Burgessomedusa phasmiformis jellyfish specimens (middle ideal ROMIP 65789– see close up images) and of the leading arthropod predator Anomalocaris canadensis preserved on the same rock surface. Burgessomedusa includes to the complexity of Cambrian foodwebs, and like Anomalocaris which lived in the very same environment, these jellyfish were effective swimming predators,” stated co-author, Dr. Jean-Bernard Caron, ROMs Richard Ivey Curator of Invertebrate Palaeontology.
Burgessomedusa Fossils and Their Features
Burgessomedusa fossils are incredibly well preserved at the Burgess Shale thinking about jellyfish are roughly 95% composed of water. By comparison with modern-day jellyfish, Burgessomedusa would likewise have been capable of free-swimming and the existence of arms would have made it possible for catching large prey.
Piece showing one big and one small (rotated 180 degrees) bell-shaped specimens with conservation of arms. ROMIP 65789. Credit: Photo by Jean-Bernard Caron © Royal Ontario Museum
” Although jellyfish and their loved ones are believed to be one of the earliest animal groups to have actually progressed, they have been remarkably hard to determine in the Cambrian fossil record. This discovery leaves no doubt they were swimming about at that time,” said co-author Joe Moysiuk, a Ph.D. candidate in Ecology & & Evolutionary Biology at the University of Toronto, who is based at ROM.
The Significance of the Burgessomedusa Discovery
This research study, identifying Burgessomedusa, is based upon fossil specimens found at the Burgess Shale and primarily discovered in the late 1980s and 1990s under former ROM Curator of Invertebrate Palaeontology Desmond Collins. They show that the Cambrian food chain was far more intricate than previously believed, which predation was not restricted to big swimming arthropods like Anomalocaris (see field image showing Burgessomedusa and Anomalocaris preserved on the very same rock surface).
Field images of Burgessomedusa phasmiformis jellyfish specimens (middle right ROMIP 65789– see close up images) and of the leading arthropod predator Anomalocaris canadensis protected on the same rock surface area. Hammer for scale. Credit: Photo by Desmond Collins. © Royal Ontario Museum
” Finding such incredibly fragile animals preserved in rock layers on top of these mountains is such a wonderous discovery. Burgessomedusa adds to the complexity of Cambrian foodwebs, and like Anomalocaris which lived in the exact same environment, these jellyfish were effective swimming predators,” stated co-author, Dr. Jean-Bernard Caron, ROMs Richard Ivey Curator of Invertebrate Palaeontology. “This adds yet another exceptional family tree of animals that the Burgess Shale has actually preserved narrating the development of life in the world.”
Detail of previous image showing Burgessomedusa phasmiformis jellyfish specimens (middle right ROMIP 65789) and of the top arthropod predator Anomalocaris canadensis. Credit: Photo by Desmond Collins. © Royal Ontario Museum
The Elusive Origins of the Medusa Form
Cnidarians have complex life cycles with a couple of body types, a vase-shaped body, called a polyp, and in medusozoans, a bell or saucer-shaped body, called a medusa or jellyfish, which can be free-swimming or not. While fossilized polyps are understood in ca. 560-million-year-old rocks, the origin of the free-swimming medusa or jellyfish is not well understood.
Fossils of any kind of jellyfish are extremely unusual. As a repercussion, their evolutionary history is based upon microscopic fossilized larval phases and the results of molecular studies from living species (modeling of divergence times of DNA sequences).
ROM Burgess Shale fieldwork website in Yoho National Park, Raymond Quarry, in 1992. Credit: Photo by Desmond Collins. © Royal Ontario Museum
Some fossils of comb-jellies have likewise been discovered at the Burgess Shale and in other Cambrian deposits, and may ostensibly look like medusozoan jellyfish from the phylum Cnidaria, comb-jellies are really from a rather different phylum of animals called Ctenophora. Previous reports of Cambrian swimming jellyfish are reinterpreted as ctenophores.
Reference: “A macroscopic free-swimming medusa from the middle Cambrian Burgess Shale” by Justin Moon, Jean-Bernard Caron and Joseph Moysiuk, 2 August 2023, Proceedings of the Royal Society B Biological Sciences.DOI: 10.1098/ rspb.2022.2490.
Financing: NSERC Discovery Grant.
Display of Burgessomedusa phasmiformis in the Burgess Shale section of ROM Willner Madge Gallery, Dawn of Life. Credit: Photo by David McKay. © Royal Ontario Museum.
The Burgess Shale fossil sites are situated within Yoho and Kootenay National Parks and are managed by Parks Canada. Parks Canada is happy to deal with leading clinical scientists to expand understanding and understanding of this essential period of Earth history and to share these websites with the world through acclaimed assisted walkings. The Burgess Shale was designated a UNESCO World Heritage Site in 1980 due to its exceptional universal worth and is now part of the bigger Canadian Rocky Mountain Parks World Heritage Site.
Visitors to ROM can see fossils of Burgessomedusa phasmiformis on display screen in the Burgess Shale area of the recently opened Willner Madge Gallery, Dawn of Life.
