Everett C. Olson

Everett Claire Olson (November 6, 1910 – November 27, 1993) was an American zoologist, paleontologist, and geologist noted for his seminal research of origin and evolution of vertebrate animals.[1][2][3] Through his research studying terrestrial vertebrate fossils he identified intervals of extinction in the Permian[4] and Triassic.[5] He developed the concept of chronofauna, which he defined as "a geographically restricted, natural assemblage of interacting animal populations that has maintained its basic structure over a geologically significant period of time".[6] He also proposed stratigraphic correlations between North American (especially the Chickasha and San Angelo Formations) and Russian vertebrate-bearing strata[4] for which additional support was found much later.[7][8][9] The drop in terrestrial vertebrate diversity he proposed in at the end of the Kungurian stage of the Permian period that occurred 270 million years ago now carries his name - Olson's Extinction. Alternatively, some scientists think that the change was gradual but that it looks abrupt because of a gap in the fossil record, called "Olson's Gap".[10][8][11][12] Some of his other notable research also included the taxa Slaugenhopia,[13] Trimerorhachis, and Waggoneria.[14]

Olson was a former chair of the department of Biology at the UCLA,[1][2] a member of the National Academy of Sciences,[1][2] a recipient of Paleontological Medal of the Paleontological Society (1987),[2] the first recipient of the Romer-Simpson Medal of the Society of Vertebrate Paleontology,[2] a CSEOL Distinguished Scientist (1991).[2] University of California said that Olson "was an internationally recognized pioneer in studies of the origin and evolution of vertebrate animals".[2] The University of Chicago said that he "carried out pioneering research on the evolution of terrestrial ecosystems".[3] The National Academy of Sciences said that he ranked "among the great vertebrate paleontologists of the twentieth century".[1]

  1. ^ a b c d National Academy Press:Biographical Memoirs:Everett C. Olson;By Michael A. Bell
  2. ^ a b c d e f g University of California; In Memoriam;Everett Claire Olson, Biology: Los Angeles; Professor Emeritus
  3. ^ a b University of Chicago:Department of the Geophysical Sciences:About Us:Everett C. Olson was trained as a vertebrate paleontologist and carried out pioneering research on the evolution of terrestrial ecosystems
  4. ^ a b Olson, Everett C. (1962). "Late Permian Terrestrial Vertebrates, U. S. A. and U. S. S. R." Transactions of the American Philosophical Society. 52 (2): 1–224. doi:10.2307/1005904. ISSN 0065-9746. JSTOR 1005904.
  5. ^ Olson, Everett C. (1982). "Extinctions of Permian and Triassic nonmarine vertebrates". Geological Implications of Impacts of Large Asteroids and Comets on the Earth. Geological Society of America Special Papers. Vol. 190. pp. 501–512. doi:10.1130/SPE190-p501. ISBN 0-8137-2190-3. ISSN 0072-1077.
  6. ^ Olson, Everett C. (1952). "The Evolution of a Permian Vertebrate Chronofauna". Evolution. 6 (2): 181–196. doi:10.2307/2405622. ISSN 0014-3820. JSTOR 2405622.
  7. ^ Reisz, Robert R.; Laurin, Michel (1 September 2001). <1229:TRMFVE>2.0.CO;2 "The reptile Macroleter: First vertebrate evidence for correlation of Upper Permian continental strata of North America and Russia". GSA Bulletin. 113 (9): 1229–1233. Bibcode:2001GSAB..113.1229R. doi:10.1130/0016-7606(2001)113<1229:TRMFVE>2.0.CO;2. ISSN 0016-7606.
  8. ^ a b Brocklehurst, Neil (10 June 2020). "Olson's Gap or Olson's Extinction? A Bayesian tip-dating approach to resolving stratigraphic uncertainty". Proceedings of the Royal Society B: Biological Sciences. 287 (1928): 20200154. doi:10.1098/rspb.2020.0154. PMC 7341920. PMID 32517621.
  9. ^ Laurin, Michel; Hook, Robert W. (2022). "The age of North America's youngest Paleozoic continental vertebrates: a review of data from the Middle Permian Pease River (Texas) and El Reno (Oklahoma) Groups". BSGF - Earth Sciences Bulletin. 193: 10. doi:10.1051/bsgf/2022007. ISSN 1777-5817.
  10. ^ Brocklehurst, Neil; Day, Michael O.; Rubidge, Bruce S.; Fröbisch, Jörg (12 April 2017). "Olson's Extinction and the latitudinal biodiversity gradient of tetrapods in the Permian". Proceedings of the Royal Society B: Biological Sciences. 284 (1852): 20170231. doi:10.1098/rspb.2017.0231. PMC 5394676. PMID 28381616.
  11. ^ Didier, Gilles; Laurin, Michel (9 December 2021). "Distributions of extinction times from fossil ages and tree topologies: the example of mid-Permian synapsid extinctions". PeerJ. 9: e12577. doi:10.7717/peerj.12577. ISSN 2167-8359. PMC 8667717. PMID 34966586.
  12. ^ Modesto, Sean P.; Smith, Roger M. H.; Campione, Nicolás E.; Reisz, Robert R. (December 2011). "The last "pelycosaur": a varanopid synapsid from the Pristerognathus Assemblage Zone, Middle Permian of South Africa". Naturwissenschaften. 98 (12): 1027–1034. Bibcode:2011NW.....98.1027M. doi:10.1007/s00114-011-0856-2. PMID 22009069. S2CID 27865550.
  13. ^ Diplocaulus Parvus N. SP.
  14. ^ The evolution of a Permian vertebrate;Everett C Olson