Charniodiscus

Charniodiscus
Temporal range: Ediacaran, [1]
A cast of Charniodiscus concentricus taken from Charnwood Forest, England
Taphonomic stop-motion model of C. concentricus
Scientific classification
Kingdom: Animalia
Phylum: Petalonamae
Class: Arboreomorpha
Genus: Charniodiscus
Ford, 1958
Species
  • C. concentricus Ford, 1958 (type species)
  • C. procerus LaFlamme et al., 2004
  • C. yorgensis? Borchvardt et Nessov, 1999[2][3]

Charniodiscus is an Ediacaran fossil that in life 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 a wide frond, and another with a long stalk, elevating a smaller frond about 50 centimetres (20 in) 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 Charnwood Forest in England, and named by Trevor D. Ford in 1958. The name is derived from the fact that Ford described a holdfast consisting only of a double concentric 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 565 to 550 million years ago.

Species are distinguished by the number of segments, the presence or absence of distal spines, and by shape ratios.

The former species C. arboreus, C. oppositus, and C. spinosus are considered to belong to their own genus Arborea, which was formerly treated as a synonym of Charniodiscus.[4] Another former species, C. longus, was in 2023 transferred to its own genus, Akrophyllas.[5] The status of C. yorgensis needs to be restudied.[4]

See also

References

  1. ^ McIlroy, D.; Denyszyn, S.; Olschewski, P.; Rosse-Guillevic, S.; Muirhead-Hunt, H.; Pérez-Pinedo, D.; McKean, C.; Pasinetti, G.; Rideout, B.; Steele, M.P.; Menon, L.R.; Neville, J.M.; Chida, N.; Taylor, R.S. (29 January 2026). "Ediacaran endlings from the Avalon Assemblage and the severity of the Kotlin Crisis: First documentation of the Inner Meadow Lagerstätte, Newfoundland, Canada". Geology. doi:10.1130/G54217.1.
  2. ^ Borchvardt, D. V.; Nessov, L. A. (1999). "New records of remains of Vendian (Precambrian) Metazoan organisms from the Zimniy Bereg of the White Sea" [Новые находки остатков многоклеточных вендских (докембрийских) организмов с Зимнего берега Белого моря]. Trudy Zoologicheskogo Instituta Rossiyskoy Akademii Nauk [Proceedings of the Zoological Institute of the Russian Academy of Sciences] (in Russian). 277: 50–57.
  3. ^ Ivantsov, A. Yu. (2016). "Reconstruction of Charniodiscus yorgensis (Macrobiota from the Vendian of the White Sea)" (PDF). Paleontological Journal. 50 (1): 1–12. doi:10.1134/S0031030116010032.
  4. ^ a b Pérez-Pinedo, Daniel; McKean, Christopher; Taylor, Rod; Nicholls, Robert; McIlroy, Duncan (2022). "Charniodiscus and Arborea Are Separate Genera Within the Arboreomorpha: Using the Holotype of C. concentricus to Resolve a Taphonomic/Taxonomic Tangle". Frontiers in Earth Science. 9: 1393. Bibcode:2022FrEaS...9.1393P. doi:10.3389/feart.2021.785929. ISSN 2296-6463.
  5. ^ Grimes, Kelsey F.; Narbonne, Guy M.; Gehling, James G.; Trusler, Peter W.; Dececchi, T. Alexander (March 2024). "Elongate Ediacaran fronds from the Flinders Ranges, South Australia". Journal of Paleontology. 98 (2): 249–265. doi:10.1017/jpa.2023.45.