British and Canadian researchers have discovered a fossil that is the earliest known evidence of animals with muscles.
The fossil, named Haootia quadriformis, dates back 560 million years and is from the Ediacaran period. It was discovered in the Bonavista Peninsula in Newfoundland.
The fossil is a cnidarians — a group of animals which today includes jellyfish, anemones and corals — and it has visible bundles that represent muscular tissue.
This would make it not only a rare example of an Ediacaran animal, but also one of the oldest fossils to show evidence of muscle anywhere in the world, the researchers said. It was largely believed until recently that the spread of animals began during the Cambrian Explosion, starting 541 million years ago.
The study, which also involved researchers from Oxford University and Memorial University in Newfoundland, was published Wednesday in the journal Proceedings of The Royal Society B.