Charnia is a genus of frond-like Ediacaran lifeforms with segmented, leaf-like ridges branching alternately to the right and left from a zig-zag medial suture (thus exhibiting glide reflection, or opposite isometry). The genus Charnia was named after Charnwood Forest in Leicestershire, England, where the first fossilised specimen was found. Charnia is significant because it was the first Precambrian fossil to be recognized as such.
The living organism grew on the sea floor and is believed to have fed on nutrients in the water. Despite Charnia‘s fern-like appearance, it is not a photosynthetic plant or alga because the nature of the fossilbeds where specimens have been found implies that it originally lived in deep water, well below the photic zone where photosynthesis can occur.
Several Charnia species were described but only the type species C. masoni is considered valid. Some specimens of C. masoni were described as members of genus Rangea or a separate genus Glaessnerina:
- Rangea grandis Glaessner & Wade, 1966 = Glaessnerina grandis
- Rangea sibirica Sokolov, 1972 = Glaessnerina sibirica
Two other described Charnia species have been transferred to two separate genera
- Charnia wardi Narbonne & Gehling, 2003 transferred to the genus Trepassia Narbonne et al., 2009
- Charnia antecedens Laflamme et al., 2007 transferred to the genus Vinlandia Brasier, Antcliffe & Liu, 2012
A number of Ediacaran form taxa are thought to represent Charnia (or Charniodiscus) at varying levels of decay; these include the IvesheadiomorphsIvesheadia, Blackbrookia, Pseudovendia and Shepshedia.
Charnia masoni was first described from the Maplewell Group in Charnwood Forest in England and subsequently was found in Ediacara Hills in Australia,Siberia and White Sea area in Russia and Precambrian deposits in Newfoundland, Canada.
It lived around 570-550 million years ago.