Researchers from the University of Cambridge, University of Oxford and Memorial University of Newfoundland interpreted a recently discovered fossil as cnidarian and have dubbed it as the earliest evidence of muscles in animals. The cnidarians are a group which contains modern animals such as corals, sea anemones and jellyfish.
The fossil dating back 560 million years ago was discovered in Newfoundland, Canada. On the basis of its four-fold symmetry, morphological characteristics, and what appeared to be some of the earliest impressions of muscular tissue, scientists concluded that the fossil belonged to the cnidarian family. Scientists have always linked origin, evolution and spread of animals to the Cambrian period, a rapid evolutionary development starting 541 million years ago. The new fossil named Haootia quadriformis dates from the Ediacaran Period, an interval spanning 635 to 541 million years ago. It differs from any previously described Ediacaran fossil as it comprises bundles of fibres in a broadly four-fold symmetrical arrangement: a body plan that is similar to that seen in modern cnidarians.
Similarities between Haootia quadriformis and both living and fossil cnidarians suggest that the organism was probably a cnidarian and that the bundles 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.