Oldest adult jellyfish fossil ever found is over 500 million years old

A fossil unearthed in Canada is the oldest preserved grownup jellyfish discovered, relationship from over 500 million years in the past.

During the Nineteen Eighties and Nineties, scientists uncovered exceptionally preserved stays of a variety of marine organisms, together with jellyfish, within the Burgess Shale, a fossil-rich deposit within the Canadian Rockies.

“The Burgess Shale is known for incredible quality of preservation, including animals that still have their eyes, stomachs and guts, sometimes with the last meals still preserved inside,” says Joe Moysiuk on the University of Toronto in Canada.

In the years since being excavated, nevertheless, many of those fossils have sat untouched within the Royal Ontario Museum in Toronto.

Among them, Moysiuk and his colleagues have recognized the earliest file of an grownup jellyfish. The specimen belongs to a brand new species, which the crew named Burgessomedusa phasmiformis. “This means essentially the Burgess Shale jellyfish, with a ghost-like form,” he says. “That’s because of its general body shape, which we thought looked a little bit like the ghost from [the video game] Pac-Man.”

The historic animal appears fairly much like fashionable jellyfish, says Moysiuk, measuring 20 centimetres lengthy, with a big bell-shaped physique and greater than 90 tentacles across the edge. The jellyfish was caught in an undersea mud circulate round 500 million years in the past, which quickly buried it.

Jellyfish have a fancy life cycle through which they tackle two distinct varieties: polyps and medusas. In their polyp stage, which is likely one of the first steps in a jellyfish’s life, they dwell on the seafloor and reproduce asexually. They then mature into medusas, which may freely swim and mate with different jellyfish.

Previous excavations have revealed 560-million-year-old fossils of polyps. “But this is the first time that we have definitive evidence of a large swimming jellyfish during this time,” says Moysiuk, which means that jellyfish had developed this life cycle a minimum of half a billion years in the past.