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Are Hypercalcified Demosponges A Key To The End-Permian Extinction?

Robert M. Finks Department of Geology Union College Schenectady, NY. Are Hypercalcified Demosponges A Key To The End-Permian Extinction?. HYPERCALCIFIED DEMOSPONGES ARE ALMOST THE ONLY SPONGES TO SURVIVE THE END-PERMIAN EXTINCTION.

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Are Hypercalcified Demosponges A Key To The End-Permian Extinction?

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  1. Robert M. FinksDepartment of Geology Union College Schenectady, NY Are Hypercalcified Demosponges A Key To The End-Permian Extinction?

  2. HYPERCALCIFIED DEMOSPONGES ARE ALMOST THE ONLY SPONGES TO SURVIVE THE END-PERMIAN EXTINCTION

  3. THE HIGH SURVIVAL RATE OF HYPERCALCIFIED DEMOSPONGES SUPPORTS THE HYPOTHESIS THAT THE END-PERMIAN EXTINCTION WAS CAUSED BY: • (1) HYPOXIA • (2) ATTENDANT DISRUPTION OF FOOD-CHAIN • (3) ATTENDANT HIGH ULTRAVIOLET FLUX BECAUSE OF LOSS OF OZONE LAYER

  4. REASONS: • (1) DEMOSPONGES CAN HAVE SYMBIOTIC CYANOBACTERIA • (2) HYPERCALCIFIED DEMOSPONGES CAN USE SYMBIOTIC CYANOBACTERIA TO HELP PRECIPITATE THEIR SKELETON • (3) SYMBIOTIC CYANOBACTERIA ARE A SOURCE OF BOTH OXYGEN AND FOOD • (4) THE HEAVY EXOSKELETON OF HYPERCALCIFIED DEMOSPONGES CAN SCREEN OUT ULTRAVIOLET LIGHT

  5. HYPERCALCIFIED DEMOSPONGES • THEY GENERALLY HAVE: • (1) MODULAR GROWTH • (2) AN EXTERNAL SKELETON OF SOLID ARAGONITE (MORE RARELY Mg-CALCITE) FORMED ON THE PREVIOUS MODULE.

  6. Aragonite vs. Calcite Seas(Ries, Stanley and Hardie, 2006)

  7. HERE ARE SOME PERMIAN HYPERCALCIFIED DEMOSPONGES THAT SURVIVED THE END-PERMIAN EXTINCTION

  8. GIRTYOCOELIA FINKS & RIGBY, 2004

  9. CYSTAULETES FINKS PHOTO

  10. HERE IS ONE COMMON HYPERCALCIFIED DEMOSPONGE THAT DID NOT SURVIVE THE END-PERMIAN EXTINCTION, ALTHOUGH CLOSE RELATIVES DID.

  11. GUADALUPIA FINKS PHOTO

  12. GUADALUPIA MAY NOT HAVE SURVIVED BECAUSE THE UPPER SURFACE LACKED AN EXOSKELETON TO SCREEN OUT ULTRAVIOLET LIGHT.

  13. Atmospheric O2 and CO2 Through Time(Huey and Ward, 2005)

  14. DEMOSPONGES ARE THE ONLY METAZOA TODAY THAT HAVE SYMBIOTIC CYANOBACTERIA

  15. IF THE PERMIAN HYPERCALCIFIED DEMOSPONGES HAD SYMBIOTIC CYANOBACTERIA, THEIR PHOTOSYNTHETIC OXYGEN MIGHT HAVE ENABLED THEM TO SURVIVE ANOXIA THEY MAY HAVE HAD SYMBIOTIC CYANOBACTERIA TO HELP THEM SECRETE THEIR BASAL SKELETON OF CaCO3

  16. 2HCO3- + Ca++  H2O + CaCO3 + CO2  Precipitation of CaCO3 nCO2 + n H2O (CH2O)n + nO2  Photosynthesis

  17. RECENT DEMOSPONGES ALSO FEED ON THEIR SYMBIOTIC CYANOBACTERIA THIS COULD ALSO HAVE HELPED THE PERMIAN HYPERCALCIFIED DEMOSPONGES TO SURVIVE THE EXTINCTION EVENT

  18. VERONGIA SP. FRED ADELL

  19. CYANOBACTERIA IN VERONGIA AEROPHOBA SARA & VACELET, 1973

  20. ANTARCTIC IMPACT (VON FRESE & POTTS, 2006) AND RESULTANT SIBERIAN FLOOD BASALTS ARE AN ADEQUATE CAUSE FOR HYPOXIA

  21. Paleomap Project Christopher R. Scotese, 2003 http://www.scotese.com/info.htm END PERMIAN EARTH ,

  22. MERCURY CALORIS BASIN IMPACT STRAUM & SPRAGUE, 2003

  23. Mars Orbiter Laser Altimeter NASA

  24. THE IMPACTOR MAY HAVE LOOKED LIKE THIS. PHOEBE, A MOON OF SATURN, MAY BE A CAPTURED KUIPER BELT OBJECT, ITS SURFACE IS CO2 ICE. (NASA, CASSINI ORBITER)

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