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Amy Davidson Division of Paleontology, American Museum of Natural History

Amy Davidson Division of Paleontology, American Museum of Natural History

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Amy Davidson Division of Paleontology, American Museum of Natural History

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  1. The use of cyanoacrylates and Butvar B-76 (polyvinyl butyral) on a specimen of Shuvuuia deserti (IGM 100/977)from Ukhaa Tolgod, Gobi Desert, Mongolia Amy Davidson Division of Paleontology, American Museum of Natural History

  2. The use of cyanoacrylates and Butvar B-76 (polyvinyl butyral) on a specimen of Shuvuuia deserti (IGM 100/977)from Ukhaa Tolgod, Gobi Desert, Mongolia Specimenin preparation, 1994

  3. BUTVAR Trade Name: Butvar Trade Name: Krazy Glue®

  4. BUTVAR Trade Name: Butvar Grade: B-76 Chemical name: polyvinyl butyral Manufacturer: Monsanto Date of purchase: 1986 Trade Name: Krazy Glue® Grade: 201 ethyl white cap(low viscosity) Chemical name: cyanoacrylate Manufacturer: Borden, Inc. Date of purchase: 1994

  5. SOLUTION ADHESIVE (sets by evaporation of a solvent) REACTION ADHESIVE (sets by irreversible chemical reaction) BUTVAR Trade Name: Butvar Grade: B-76 Chemical name: polyvinyl butyral Manufacturer: Monsanto Date of purchase: 1986 Trade Name: Krazy Glue® Grade: 201 ethyl white cap (low viscosity) Chemical name: cyanoacrylate Manufacturer: Borden, Inc. Date of purchase: 1994

  6. SOLUTION ADHESIVE (sets by evaporation of a solvent) REACTION ADHESIVE (sets by irreversible chemical reaction) BUTVAR Shallow, weak, resoluble Penetrates, strong, insoluble Trade Name: Butvar Grade: B-76 Chemical name: polyvinyl butyral Manufacturer: Monsanto Date of purchase: 1986 Trade Name: Krazy Glue® Grade: 201 ethyl white cap (low viscosity) Chemical name: cyanoacrylate Manufacturer: Borden, Inc. Date of purchase: 1994

  7. IGM 100/977 fifteen years ago

  8. IGM 100/977 now

  9. 2,000 gallons (7,570 liters) of fuel On the road from Ulaanbaatar, 1993

  10. UKHAA TOLGOD

  11. An oviraptorid in-situ Typical Ukhaa Tolgod preservation

  12. broken bone in cross-section Bone is soft, porous and weak

  13. Excavating ”Big Mama”

  14. Plastic eyedropper for dispensing Extraction impossible without consolidation Heavy consolidation with Butvar B-76 is essential

  15. “Big Mama” Preparedwith Butvar B-76 Oviraptorid in brooding posture over nest of eggs

  16. Two oviraptorids juvenile protoceratopcians Prepared with Butvar B-76 Photos Mick Ellison

  17. 140 lb. (63.5 kg) barrel Date of purchase: 1986 ButvarB-76 has a long shelf life and is a very stable material Feller, R.L. et al. 2007. Photochemical deterioration of poly (vinylbutyral) in the range of wavelengths from middle ultraviolet to the visible. Polymer Degradation and Stability 92 (5): 920-931.

  18. Butvar B-76 is soluble in a wide range of solvents a more commonly available solvent a rare bottle of lab grade ethanol

  19. Butvar B-76 coatings are very easily re-dissolved and reworked

  20. Butvar B-76 coatings are weakly adhesive… …and easy to peel off.

  21. Matrix is consolidated yet easily removed

  22. Butvar B-76 can be mixed with ground matrix to form a paste

  23. Butvar B-76 and matrix pastes are strong yet easily reworked or removed

  24. Butvar B-76 is a shallow but effective surface consolidant

  25. Saichangurvel davidsoni • Heavy coatings can be reduced later • Shallow, weak consolidation does not interfere with preparation • Butvar B-76 has an aesthetically pleasing matte finish Photo Mick Ellison

  26. Return to Ukhaa Tolgod 1994

  27. Specimen in-situ

  28. Mononykus?

  29. Forelimb of Mononykus olecranus Casts and mount - Dennis Wilson and Marilyn Fox Photo- Mick Ellison

  30. ? The first complete skull ?

  31. Heavy consolidation with Butvar B-76

  32. Preparation from bottom AMNH prep lab 1994

  33. Preparation up toward consolidated surface…

  34. Preparation halted

  35. Fibers associated with bones

  36. Feathers Fibers- no adhesive present SEM images show similar structure

  37. Isolated fibers embedded in LR White acrylic and thin-sectioned • Digestion with cellulase – not plant or fungus • Transmission electron microscopy- hollow structure • Time of flight secondary ion mass spectroscopy –original molecules present • Immunohistological studies- beta-keratin in fibers is comparable to beta-keratin in feathers

  38. Schweitzer,M.H. et al. 1999. Beta-keratin specific immunological reactivity in feather-like structures of the Cretaceous alvarezsaurid, Shuvuuia deserti. Journal of Experimental Zoology (Mol Dev Evol) 285:146-157. Direct evidence that IGM 100/977 was covered with feathers

  39. Skull separated from postcrania for continued preparation Why cyanoacrylates?

  40. Cyanoacrylates are effective micro-consolidants- can wick into tiny cracks and pores Cyanoacrylates form extremely thin, hard coatings Cyanoacrylate coatings are insoluble but can be softened and removed on a tiny scale The tiny teeth of IGM 100/977

  41. Cyanoacrylates can be applied in extremely tiny drops

  42. Krazy Glue® Type 201 Ethyl White Cap™ Date of purchase: 1994 Aron Alpha ® Industrial Krazy Glue Type 201 Date of Purchase: 2009 How will they age? Down, J.L. and E. Kaminska. 2006. A preliminary study of the degradation of cyanoacrylate adhesives in the presence and absence of fossil material. Journal of Vertebrate Paleontology 26 (3): 519-525.

  43. How to make this strong enough to handle?

  44. Reinforcement with Butvar B-76 and matrix

  45. Cyanoacrylate and fiberglass armature

  46. Attaching a removable armature

  47. Butvar B-76 and matrix paste over armature to build handle