Living organisms have populated the Earth for more than 3.5 billion years. Most of these organisms were single-celled and were rather small. Life started to change greatly during the late Proterozoic era, about 580 million years ago. In rocks dating from this time, paleontologists have found a wide variety of large impressions left by a group of mysterious soft-bodied organisms called the Ediacara fauna. They later disappeared from the fossil record.

Ediacara fauna is the animal life that lived during the Vendian or Ediacaran period of the Precambrian stage of earth history (roughly 650 to 544 million years ago). Many scientists believe the Precambrian began about 3.8 billion years ago and ended 540 million years ago. These creatures are the first multicellular animals in the Fossil record. The Ediacara are soft-bodied, multicellular animals that are similar jellyfish, coral, sponges, cnidarians, worms, and soft-bodied relatives of the arthropods.

The Ediacara was named for the Ediacara Hills in the Flinders Ranges in Australia where these early animal fossils were first found. Reginald C.Sprigg, an Australian mining geologist, found abundant fossils in the hills in 1946. More than 600 Ediacaran specimens have been collected. Paleontologists speculate the nature of these organisms, wondering whether they were animals, plants, fungi, or something different. They closely resemble the Burgess Shale organisms. Also, some scientists believe that many of these Ediacara fauna might have survived into the Cambrian period.