The newfound species, Helicocystis moroccoensis, has "characteristics that place it as the most primitive echinoderm that has fivefold symmetry," said study co-author Andrew Smith, a paleontologist at the Natural History Museum in London, referring to the group of animals that includes starfish and sea urchins. Modern echinoderms typically have five-point symmetry, such as the five arms of the starfish or the sand dollar's distinctive pattern.

The primitive sea creature, described today (June 25) in the journal Proceedings of the Royal Society B, could even change its body shape from slender to stumpy. Researchers say it is a transitional animal that could help explain how early echinoderms evolved their unique body plans, Smith said.