Val et al., 2014: CHEMICAL PREPARATION OF DINOSAUR EGGSHELLS
Figure 4: Eggshells treated with alkalies. A) Potassium hydroxide KOH at 10%. The relief of the eggshell could be observed, the surface has not
been altered and the oxygenation channels were also detected (arrows). B) Sodium hydroxide NaOH at 4%. The relief of the eggshell could be
observed, but the surface was slightly damaged (red arrows). The oxygenation channels were observable (yellow arrows). C) Potassium hydroxide
KOH at 10%. The relief has not been damaged and the oxygenation channels (arrows) are perfectly observable.
Figure 5: Eggshells treated with mixtures: A) Waller Method: Sodium citrate 71gr + Sodium bicarbonate 8,5gr + Sodium dithionite 20gr. It is
possible to observe the oxygenation channels (arrows) and the relief perfectly. B) Ethylenediaminetetraacetic acid (EDTA) at 5%. The oxygenation
channels could be detected (yellow arrows) but the relief was highly eroded (red arrows). C) Ethylenediaminetetraacetic acid (EDTA) at 5% with
Sodium hydroxide at 4%. The relief of the eggshell could be observed, its surface was somewhat altered (red arrows) and the oxygenation
channels could be detected (yellow arrows). D) Sodium hexametaphospate at 15% + Waller Method. The relief has been partially eroded (red
arrows).
34 Journal of Paleontological Techniques