Kimberella

Kimberella quadrata is a fossil animal from the Ediacaran or Vendian fauna. This fossil varies from 3mm to 10 cm in size. It is oval in shape with larger ones being elongated more. The long axis has a raised ridge, and the edge is crenulated or scalloped with 44 lobes, though some always appear missing. The organism that caused this fossil is believed to be a bilaterian organism, with bilateral symmetry. As such it is the earliest known bilaterian animal. It may represent the ancestor of all bilaterian animals including humans or may be a lophotrochozoan ancestor. It has been interpreted as a mollusc with a non mineralised shell. It may be the cause of the long trails found in the Ediacaran strata.

It was first described by Glaessner & Daily in 1959. Fossils are found in the Ediacara Hills in South Australia and in the White Sea region in Russia.