Charniodiscus

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Charniodiscus
Fossil range: Ediacaran — 565–555 Ma
A cast of Charniodiscus taken from Mistaken Point
A cast of Charniodiscus taken from Mistaken Point
Scientific classification
Kingdom: incertae sedis
Order: Rangeomorpha?
Genus: Charniodiscus
Species
  • Charniodiscus arborea
  • Charniodiscus oppositus
  • Charniodiscus procerus
  • Charniodiscus spinosus

Charniodiscus is an Ediacaran fossil that was probably a stationary filter feeder that lived anchored to a sandy sea bed. The organism had a holdfast, stalk and frond. The holdfast was bulbous shaped, and the stalk was flexible. The frond was segmented and had a pointed tip. There were two growth forms; one with a short stem and fat frond, and another with a long stalk, elevating a smaller frond about 50 cm above the holdfast. While the organism superficially resembles the sea pens (cnidaria), it is probably not a crown-group animal.

Charniodiscus was first found in the Charnwood Forest in England, and named by Trevor D. Ford in 1958. The name is derived from the fact that Ford only described a holdfast consisting of a double concentic circle, his species being named Charniodiscus concentricus. Later it was discovered that a frond (Charnia masoni) was part of a closely related organism. Charnia differs in the branching structure in the frond.

Charniodiscus specimens are known from across the globe dating to around Expression error: Unexpected round operator Expression error: Unexpected round operator million years ago.

Species are distinguished by the number of segments, whether or not there is a distal spine, and the shape ratio.

Charniodiscus was featured on a AUS$1 stamp on April 21, 2005.

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