Horodyskia

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Horodyskia
Temporal range: 1500 - 900 Ma
Horodyskia moniliformis.jpg
Horodyskia moniliformis, "string-of-beads fossil" from the 1.4 Ga Appekunny Argillite of Glacier National Park, Montana[1])
Scientific classification
Kingdom: Fungi
Phylum: Glomeromycota
Order: Archaeosporales
Family: Geosiphonaceae
Genus: Horodyskia
Species

Horodyskia is a fossilised organism found in rocks dated from 1,500 million years ago to 900 million years ago. Its shape has been described as a "string of beads" connected by a very fine thread.[2] It may also have had a series of holdfasts along the bottom of the thread.[3]

Horodyskia apparently re-arranged itself into fewer but larger main masses as the sediment grew deeper round its base.[2]

Comparisons of different fossils in the same locations suggest that it re-arranged itself into fewer but larger main masses as the sediment grew deeper round its base.[2]

Horodyskia has been considered an early metazoan,[2] and a colonial foraminiferan.[4] These alternatives are now considered less likely than a Geosiphon-like fungus (Glomeromycota, Archaeosporales[1]).

Footnotes[edit]

  1. ^ a b Retallack, G.J., Dunn, K.L., and Saxby, J. (2013). "Problematic Mesoproterozoic fossil Horodyskia from Glacier National Park, Montana, USA". Precambrian Research. 226: 125–142. doi:10.1016/j.precamres.2012.12.005. 
  2. ^ a b c d Fedonkin, M.A. (March 2003). "The origin of the Metazoa in the light of the Proterozoic fossil record" (PDF). Paleontological Research. 7 (1): 9–41. doi:10.2517/prpsj.7.9. Retrieved 2008-09-02. 
  3. ^ Martin, D.McB. (August 2004). "Depositional environment and taphonomy of the 'strings of beads': Mesoproterozoic multicellular fossils in the Bangemall Supergroup, Western Australia". Australian Journal of Earth Sciences. 51 (4): 555–561. doi:10.1111/j.1400-0952.2004.01074.x. Retrieved 2008-09-02. 
  4. ^ Dong, L., Xiao, S., Shen, B., and Zhou, C. (Jan 2008). "Silicified Horodyskia and Palaeopascichnus from upper Ediacaran cherts in South China: tentative phylogenetic interpretation and implications for evolutionary stasis". Journal of the Geological Society. 165: 367–378. doi:10.1144/0016-76492007-074. Retrieved 2008-09-02.