Aspidella

Aspidella is a genus of disk shaped Ediacaran fossils of uncertain biological affinity, found in Newfoundland, where it was first described, and also in British Columbia, central North Carolina and South Australia. The fossils range from 1 to 180 millimeters across, most commonly 4 to 10 millimeters, with concentric rings or centripetal rays and often a small central pimple. Early workers considered them jellyfish, but later evidence suggests many specimens are instead the attachment holdfasts of other organisms or microbial colonies, and some occur alongside trails resembling those made by modern sea anemones; because the disks look alike without necessarily sharing ancestry, Aspidella may be a form taxon rather than a true natural genus.