Kredno-paleogensko izumiranje

Kredno-paleogensko izumiranje ili kredno-tercijarno masovno izumiranje mnogih vrsta desilo se prije otprilike 66 miliona godina. Odgovara kraju perioda krede i početku paleogena (prvog razdoblja kenozoika). Ujedno je poznato i kao K/T granično masovno izumiranje (od njemačkih termina Kreide (=kreda) + Tertiär Grenze (=granica tercijera) ili K/Pg. Termin tercijar je napušten, pa se moderna naučna literatura odnosi na izumiranje kreda-paleogena (K/Pg) zbog ovog događaja.

rock in museum with layering — Stijena iz Vajominga sa srednjim slojem glinskog kamena sa 1.000 puta više iridija od gornjeg i donjeg sloja. Snimljeno u Prirodnjačkom muzeju San Dijega

Nije poznato tačno trajanje ovog događaja. Oko 75% bioloških rodova je nestalo, uključujući većinu dinosaura, leteće gmizavce (pterosaure), većinu vodenih gmizavaca (plesiosauri, pliosauri i ihtiosauri) i amonite. Mnoga su objašnjenja predložena za ovaj fenomen, a jedno od najpoznatijih tumačenja je da je bio posljedica graničnog K/T utjecaja vanzemaljskog objekta.

Kao što je to originalno predložio tim naučnika koji su predvodili Luis Walter Alvarez i njegov sin Walter Alvarez, 1980., sada se općenito smatra da je K–Pg izumiranje uzrokovano udarom masivne komete ili asteroida sa širinom 10 do 15 km,^[1]^[2] prije 66 miliona godina, kojim je opustošeno globalno životno okruženje, uglavnom usljed dugotrajne zime izazvane udarom, koja je zaustavila fotosintezu u biljkama i planktonu.^[3]^[4] Hipoteza o takvom uticaju, poznata i kao Alvarezova hipoteza, bila je ojačana otkrićem 180 km širokog kratera Chicxulub u poluotoku Jukatan kod Meksičkog zaliva početkom 90-ih godina prošlog stoljeća,^[5] koji je pružio ubedljive dokaze da granična glina kreda-paleogen predstavlja krhotine od udara asteroida.^[6] Činjenica da su istovremeno dogosila i izumiranja snažno podržava pretpostavku da ih je izazvao asteroid. Projekt bušenja u kratera Peak Chicxuluba iz 2016. godine potvrdio je da on sadrži granit koji se izbačen u toku nekoliko minuta iz dubine zemlje, ali da jedva sadrži gips, uobičajenu stijenu koja sadrži sulfat sa morskog dna tog područja: gips bi isparavao i raspršio se kao aerosol u atmosferu, izazivajući dugoročne efekte na klimu i lanac ishrane.

Ostali mogući uzročni ili dodatni faktori izumiranja mogu biti Dekanska klopka i erupije drugih vulkana,^[7]^[8] promjene klimatskih prilika i morske razine.

Veliki broj vrsta je izumro u tom događaju, od kojih su najpoznatiji dinosauri, među kojima osobito neptičji. Također je nestalo mnoštvo drugih kopnenih organizama, uključujući sisare, pterosaure, ptice,^[9]^[10] guštere,^[11] insekte,^[12]^[13] i biljke.^[14] U okeanima, K-Pg izumiranje je ubilo Plesiosauria, divovske morske guštere Mosasauriaidae i devastiralo ribe,^[15] morske pse, mehkušce (naročito amonite, koji su izumrli) i mnoge vrste planktona. Procenjuje se da je nestalo 75% ili više svih vrsta na Zemlji.^[16] Ipak, izumiranje je također pružilo evolucijske mogućnosti: nakon normalizacije ekoloških priliks, mnoge su grupe doživjele su izuzetnu adaptivnu radijaciju - nagloj i plodnoj divergenciji u nove oblike i vrste unutar poremećenih i ispraznjenih ekoloških niša. Posebno su sisari u paleogenu uvećali raznolikost,^[17] evoluirajući nove forme poput konja, kitova, šišmiša i primata. Ptice,^[18] ribe,^[19] i vjerovatno gušteri su također postali raznovrsniji i raznolikiji.^[11]

Reference

^ Sleep, Norman H.; Lowe, Donald R. (9. 4. 2014). "Scientists reconstruct ancient impact that dwarfs dinosaur-extinction blast". American Geophysical Union. Pristupljeno 30. 12. 2016.
^ Amos, Jonathan (15. 5. 2017). "Dinosaur asteroid hit 'worst possible place'". BBC News Online. Pristupljeno 16. 3. 2018.
^ Alvarez, L W; Alvarez, W; Asaro, F; Michel, H V (1980). "Extraterrestrial cause for the Cretaceous–Tertiary extinction" (PDF). Science. 208 (4448): 1095–1108. Bibcode:1980Sci...208.1095A. doi:10.1126/science.208.4448.1095. PMID 17783054. Arhivirano s originala (PDF), 25. 11. 2018. Pristupljeno 26. 6. 2020.
^ Vellekoop, J.; Sluijs, A.; Smit, J.; et al. (maj 2014). "Rapid short-term cooling following the Chicxulub impact at the Cretaceous-Paleogene boundary". Proc. Natl. Acad. Sci. U.S.A. 111 (21): 7537–41. Bibcode:2014PNAS..111.7537V. doi:10.1073/pnas.1319253111. PMC 4040585. PMID 24821785.
^ Hildebrand, A. R.; Penfield, G. T.; et al. (1991). "Chicxulub crater: a possible Cretaceous/Tertiary boundary impact crater on the Yucatán peninsula, Mexico". Geology. 19 (9): 867–871. Bibcode:1991Geo....19..867H. doi:10.1130/0091-7613(1991)019<0867:ccapct>2.3.co;2.
^ Schulte, P.; et al. (5. 3. 2010). "The Chicxulub Asteroid Impact and Mass Extinction at the Cretaceous-Paleogene Boundary" (PDF). Science. 327 (5970): 1214–1218. Bibcode:2010Sci...327.1214S. doi:10.1126/science.1177265. PMID 20203042.
^ Keller G (2012). "The Cretaceous–Tertiary Mass Extinction, Chicxulub Impact, and Deccan Volcanism. Earth and Life". u Talent JA (ured.). Earth and Life: Global Biodiversity, Extinction Intervals and Biogeographic Perturbations Through Time. Springer. str. 759–793. ISBN 978-90-481-3427-4.
^ Bianca Bosker, "The Nastiest Feud in Science:A Princeton geologist has endured decades of ridicule for arguing that the fifth extinction was caused not by an asteroid but by a series of colossal volcanic eruptions. But she's reopened that debate." The Atlantic Monthly September 2018. https://www.theatlantic.com/magazine/archive/2018/09/dinosaur-extinction-debate/565769/
^ Longrich, Nicholas R.; Tokaryk, Tim; Field, Daniel J. (2011). "Mass extinction of birds at the Cretaceous–Paleogene (K–Pg) boundary". Proceedings of the National Academy of Sciences. 108 (37): 15253–15257. Bibcode:2011PNAS..10815253L. doi:10.1073/pnas.1110395108. PMC 3174646. PMID 21914849.
^ "Primitive birds shared dinosaurs' fate". Science Daily. 20. 9. 2011. Pristupljeno 20. 9. 2011.
^ ^a ^b Longrich, N. R.; Bhullar, B.-A. S.; Gauthier, J. A. (decembar 2012). "Mass extinction of lizards and snakes at the Cretaceous-Paleogene boundary". Proc. Natl. Acad. Sci. U.S.A. 109 (52): 21396–401. Bibcode:2012PNAS..10921396L. doi:10.1073/pnas.1211526110. PMC 3535637. PMID 23236177.
^ Labandeira CC; Johnson KR; et al. (2002). "Preliminary assessment of insect herbivory across the Cretaceous-Tertiary boundary: major extinction and minimum rebound". u Hartman JH; Johnson KR; Nichols DJ (ured.). The Hell Creek formation and the Cretaceous-Tertiary boundary in the northern Great Plains: An integrated continental record of the end of the Cretaceous. Geological Society of America. str. 297–327. ISBN 978-0-8137-2361-7.
^ Rehan, Sandra M.; Leys, Remko; Schwarz, Michael P. (2013). "First evidence for a massive extinction event affecting bees close to the K-T boundary". PLOS ONE. 8 (10): e76683. Bibcode:2013PLoSO...876683R. doi:10.1371/journal.pone.0076683. ISSN 1932-6203. PMC 3806776. PMID 24194843.
^ Nichols, D. J.; Johnson, K. R. (2008). Plants and the K–T Boundary. Cambridge, UK: Cambridge University Press.
^ Friedman M (2009). "Ecomorphological selectivity among marine teleost fishes during the end-Cretaceous extinction". Proceedings of the National Academy of Sciences. Washington, DC. 106 (13): 5218–5223. Bibcode:2009PNAS..106.5218F. doi:10.1073/pnas.0808468106. PMC 2664034. PMID 19276106.
^ Jablonski, D.; Chaloner, W. G. (1994). "Extinctions in the fossil record (and discussion)". Philosophical Transactions of the Royal Society of London B. 344 (1307): 11–17. doi:10.1098/rstb.1994.0045.
^ Alroy J (1999). "The fossil record of North American Mammals: evidence for a Palaeocene evolutionary radiation". Systematic Biology. 48 (1): 107–118. doi:10.1080/106351599260472. PMID 12078635.
^ Feduccia A (1995). "Explosive evolution in Tertiary birds and mammals". Science. 267 (5198): 637–638. Bibcode:1995Sci...267..637F. doi:10.1126/science.267.5198.637. PMID 17745839.
^ Friedman M (2010). "Explosive morphological diversification of spiny-finned teleost fishes in the aftermath of the end-Cretaceous extinction". Proceedings of the Royal Society B. 277 (1688): 1675–1683. doi:10.1098/rspb.2009.2177. PMC 2871855. PMID 20133356.

Dopunska litratura

Fortey (2005). Earth: An Intimate History. New York: Vintage Books. ISBN 978-0-375-70620-2. OCLC 54537112.
Douglas Preston, "The Day the Earth Died: A young paleontologist makes the find of his life", The New Yorker, 8 April 2019, pp. 52–65. Robert A. De Palma has found strong evidence that the dinosaurs—and nearly all other life on Earth—were indeed wiped out 66 million years ago by the Chicxulub asteroid. The Day the Dinosaurs Died

Vanjski linkovi

Commons logo

Commons ima datoteke na temu: Kredno-paleogensko izumiranje

"The Great Chicxulub Debate 2004". Geological Society of London. 2004. Pristupljeno 2. 8. 2007.
Kring DA (2005). "Chicxulub Impact Event: Understanding the K–T Boundary". NASA Space Imagery Center. Arhivirano s originala, 29. 6. 2007. Pristupljeno 2. 8. 2007.
Cowen R (2000). "The K–T extinction". University of California Museum of Paleontology. Pristupljeno 2. 8. 2007.
"What killed the dinosaurs?". University of California Museum of Paleontology. 1995. Pristupljeno 2. 8. 2007.
Papers and presentations resulting from the 2016 Chicxulub drilling project
De Palma, Robert A.; et al. (1. 4. 2019). "A seismically induced onshore surge deposit at the KPg boundary, North Dakota". PNAS. 116 (17): 8190–8199. Bibcode:2019PNAS..116.8190D. doi:10.1073/pnas.1817407116.

[AGU-20140409-1] Sleep, Norman H.; Lowe, Donald R. (9. 4. 2014). "Scientists reconstruct ancient impact that dwarfs dinosaur-extinction blast". American Geophysical Union. Pristupljeno 30. 12. 2016.

[2] Amos, Jonathan (15. 5. 2017). "Dinosaur asteroid hit 'worst possible place'". BBC News Online. Pristupljeno 16. 3. 2018.

[Alvarez-3] Alvarez, L W; Alvarez, W; Asaro, F; Michel, H V (1980). "Extraterrestrial cause for the Cretaceous–Tertiary extinction" (PDF). Science. 208 (4448): 1095–1108. Bibcode:1980Sci...208.1095A. doi:10.1126/science.208.4448.1095. PMID 17783054. Arhivirano s originala (PDF), 25. 11. 2018. Pristupljeno 26. 6. 2020.

[4] Vellekoop, J.; Sluijs, A.; Smit, J.; et al. (maj 2014). "Rapid short-term cooling following the Chicxulub impact at the Cretaceous-Paleogene boundary". Proc. Natl. Acad. Sci. U.S.A. 111 (21): 7537–41. Bibcode:2014PNAS..111.7537V. doi:10.1073/pnas.1319253111. PMC 4040585. PMID 24821785.

[Hildebrand,_A._R._1991-5] Hildebrand, A. R.; Penfield, G. T.; et al. (1991). "Chicxulub crater: a possible Cretaceous/Tertiary boundary impact crater on the Yucatán peninsula, Mexico". Geology. 19 (9): 867–871. Bibcode:1991Geo....19..867H. doi:10.1130/0091-7613(1991)019<0867:ccapct>2.3.co;2.

[Schulte10-6] Schulte, P.; et al. (5. 3. 2010). "The Chicxulub Asteroid Impact and Mass Extinction at the Cretaceous-Paleogene Boundary" (PDF). Science. 327 (5970): 1214–1218. Bibcode:2010Sci...327.1214S. doi:10.1126/science.1177265. PMID 20203042.

[7] Keller G (2012). "The Cretaceous–Tertiary Mass Extinction, Chicxulub Impact, and Deccan Volcanism. Earth and Life". u Talent JA (ured.). Earth and Life: Global Biodiversity, Extinction Intervals and Biogeographic Perturbations Through Time. Springer. str. 759–793. ISBN 978-90-481-3427-4.

[8] Bianca Bosker, "The Nastiest Feud in Science:A Princeton geologist has endured decades of ridicule for arguing that the fifth extinction was caused not by an asteroid but by a series of colossal volcanic eruptions. But she's reopened that debate." The Atlantic Monthly September 2018. https://www.theatlantic.com/magazine/archive/2018/09/dinosaur-extinction-debate/565769/

[longrichetal2011-9] Longrich, Nicholas R.; Tokaryk, Tim; Field, Daniel J. (2011). "Mass extinction of birds at the Cretaceous–Paleogene (K–Pg) boundary". Proceedings of the National Academy of Sciences. 108 (37): 15253–15257. Bibcode:2011PNAS..10815253L. doi:10.1073/pnas.1110395108. PMC 3174646. PMID 21914849.

[10] "Primitive birds shared dinosaurs' fate". Science Daily. 20. 9. 2011. Pristupljeno 20. 9. 2011.

[Longrich,_N._R._2012-11] Longrich, N. R.; Bhullar, B.-A. S.; Gauthier, J. A. (decembar 2012). "Mass extinction of lizards and snakes at the Cretaceous-Paleogene boundary". Proc. Natl. Acad. Sci. U.S.A. 109 (52): 21396–401. Bibcode:2012PNAS..10921396L. doi:10.1073/pnas.1211526110. PMC 3535637. PMID 23236177.

[12] Labandeira CC; Johnson KR; et al. (2002). "Preliminary assessment of insect herbivory across the Cretaceous-Tertiary boundary: major extinction and minimum rebound". u Hartman JH; Johnson KR; Nichols DJ (ured.). The Hell Creek formation and the Cretaceous-Tertiary boundary in the northern Great Plains: An integrated continental record of the end of the Cretaceous. Geological Society of America. str. 297–327. ISBN 978-0-8137-2361-7.

[Rehan2013-13] Rehan, Sandra M.; Leys, Remko; Schwarz, Michael P. (2013). "First evidence for a massive extinction event affecting bees close to the K-T boundary". PLOS ONE. 8 (10): e76683. Bibcode:2013PLoSO...876683R. doi:10.1371/journal.pone.0076683. ISSN 1932-6203. PMC 3806776. PMID 24194843.

[Nichols,_D._J_2008-14] Nichols, D. J.; Johnson, K. R. (2008). Plants and the K–T Boundary. Cambridge, UK: Cambridge University Press.

[15] Friedman M (2009). "Ecomorphological selectivity among marine teleost fishes during the end-Cretaceous extinction". Proceedings of the National Academy of Sciences. Washington, DC. 106 (13): 5218–5223. Bibcode:2009PNAS..106.5218F. doi:10.1073/pnas.0808468106. PMC 2664034. PMID 19276106.

[Jablonski1994-16] Jablonski, D.; Chaloner, W. G. (1994). "Extinctions in the fossil record (and discussion)". Philosophical Transactions of the Royal Society of London B. 344 (1307): 11–17. doi:10.1098/rstb.1994.0045.

[Alroy,_J._1999-17] Alroy J (1999). "The fossil record of North American Mammals: evidence for a Palaeocene evolutionary radiation". Systematic Biology. 48 (1): 107–118. doi:10.1080/106351599260472. PMID 12078635.

[Feduccia,_A._1995-18] Feduccia A (1995). "Explosive evolution in Tertiary birds and mammals". Science. 267 (5198): 637–638. Bibcode:1995Sci...267..637F. doi:10.1126/science.267.5198.637. PMID 17745839.

[Friedman,_M._2010-19] Friedman M (2010). "Explosive morphological diversification of spiny-finned teleost fishes in the aftermath of the end-Cretaceous extinction". Proceedings of the Royal Society B. 277 (1688): 1675–1683. doi:10.1098/rspb.2009.2177. PMC 2871855. PMID 20133356.

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[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

[14]

[15]

[16]

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