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Grypania spiralis.JPG
Grypania spiralis fossil
Scientific classification

Walter, Oehler & Oehler, 1976[1]
Type species
Grypania spiralis
Walter, Oehler & Oehler, 1976

Grypania is an early, tube-shaped fossil from the Proterozoic eon. It is regarded by some as the first known eukaryote.[2][3]

Grypania's status as a eukaryote is not absolutely proven. It might have been a giant bacterium or bacterial colony. Its size (over one centimeter) and consistent form, suggest it is a eukaryotic alga.[2] The oldest known Grypania fossils come from an iron mine near Negaunee, Michigan. The fossils were originally dated as 2100 million years ago, but later research showed the date as about 1874 million years ago.[4] Grypania lasted into the Mesoproterozoic era.

References[change | change source]

  1. M. R. Walter, John H. Oehler & Dorothy Z. Oehler (1976). "Megascopic algae 1,300 million years old from the Belt supergroup, Montana: a reinterpretation of Walcott's Helminthoidichnites". Journal of Paleontology. 50 (5): 872–881. JSTOR 1303584.
  2. 2.0 2.1 Han T.M. & Runnegar B. 1992. Megascopic eukaryotic algae from the 2.1-billion-year-old negaunee iron-formation, Michigan. Science 257 (5067): 232–235. [1]
  3. Knoll, Andrew H. et al 2006. Eukaryotic organisms in Proterozoic oceans. Philosophical Transactions of the Royal Society B 361 (1470): 1023–38. [2]
  4. Schneider D.A. et al 2006. Age constraints for Paleoproterozoic glaciation in the Lake Superior Region: detrital zircon and hydrothermal xenotime ages for the Chocolay Group, Marquette Range Supergroup. Canadian Journal of Earth Sciences 43, 571-591, [3]

Other websites[change | change source]