Cyclomedusa is on of the most prevalent Ediacaran fossils of the Vendian period (UCMP 2009). Cyclomedusa is characterized as a radial fossil with a circular raised area in the center, with as many as five concentric growth ridges surrounding it (Wikipedia 2009). These circular ridges are thought to be folds of the outer layer, or internal tissues such as muscles (Nedin 1999). Cyclomedusa was once thought to be a planktonic jellyfish, however, since these fossils are found covered by sand, it has been concluded that these organisms were actually benthic polyps similar to sea anemones and were anchored to the sea floor instead of swimming in the water column (Clowes 2004). It has also been hypothesized that these organisms could have been microbial colonies (The Virtual Fossil Museum 2002). Currently, Cyclomedusa has no known relatives (Wikipedia 2009). There are however, a four known of species of Cyclomedusa: C. plana, C. radiata, C. gigantea, and C. davidi (Clowes 2004). These fossils are found in a variety of sizes ranging from a few millimeters to a meter in diameter (Clowes 2004). Specimens have been found around the world ranging from the White Sea in Russia to China, England, Canada, and Mexico (The Virtual Fossil Museum 2002). These fossilized eukaryotes have been found in sediments dating back to roughly 600 million years ago and are used currently in intensive research to further improve the fossil record (The Virtual Fossil Museum 2002).

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Nedin, C. 1999. Cyclomedusa davidi. Accessed January 21, 2010.

Clowes, C. 2004. The Ediacaran (Vendian)-3. www.paleos.com. Accessed January 25, 2010.

University of California Museum of Paleontology (UCMP). Vendian Animals: Cyclomedusa. Accessed January 21, 2010.

The Virtual Fossil Museum. 2002. Ediacaran Fossils of the Vendian White Sea Summer Coast, Northern Russia. Accessed January 25,

Wikipedia. 2010.Cyclomedusa. Accessed January 25, 2010