Fossils thought to be ancient marine creatures may be seaweed, study suggests

New twist in debate over whether bryozoans cropped up during Cambrian explosion or later

A group of fossils previously thought to be of ancient marine creatures may actually be of a type of seaweed, a study has suggested, hinting that the blueprints of animal life did necessarily not crop up in the same era.

Researchers say the potential of evolution to throw up novel body plans among animals did not end with the Cambrian explosion more than 500m years ago. During the Cambrian period, which began about 540m years ago, there was a huge burst in the diversity of life on Earth, with the body plans that help to define different major animal groups - such as the shells of molluscs and jointed skeletons of arthropods - cropping upabout 520m years ago.