1. Eklund, M. J. , A. K. Aase, and C. J. Bell. 2018
Eklund, M. J., A. K. Aase, and C. J. Bell Progressive Photonics: Methods and applications of sequential imaging using visible and non-visible spectra to enhance data-yield and facilitate forensic interpretation of fossils. Journal of Paleontological Techniques 20: 1-36.
Figure 10: Indeterminate avian egg (AMNH FARB 6168) from the Eocene Bridger Formation, Clark Fork Basin, Wyoming. A) The specimen imaged in polarized visible light shows calcite mineral replacement in the interior of the egg (lower right). At the top, the eggshell appears intact. The white lettering and black specimen number are placed on an area where the shell is missing. B) Under UVA wavelength with a light-balancing filter the calcite is readily differentiated by its reddish-pink color. Light blue coloration around the label is a reaction to the labeling material. The cream-colored lines along the upper left reveal a repaired fracture. The orange-yellow beneath the label represents a distinct layer within the egg; it is also visible in cross-section in at least five places, suggesting it was once a continuous (or nearly continuous) layer inside of the outer egg shell. This possibly represents a preserved membrane under the shell. These images open new avenues for investigation, preparation, and interpretation, in addition to more thoroughly documenting the specimen and aspects of its history.

2. 10A polarized light

3. 10B UVA with LA120 filter