FIGURE 1.
Images of Middle Cambrian chancelloriids. A. Allonnia, Burgess
Shale, British Columbia (ROM 49601A). Immersed in water. A1.
Plain light. A2. Red channel of image
taken with crossed nicols subtracted from green channel of image in unpolarized
light, using Adobe Photoshop’s “Subtract” blending mode (settings: Opacity
= 100, Offset = 75, Scale = 1). Levels subsequently adjusted. B. Chancelloria,
Wheeler Shale, Utah (USNM 509795). B1. Crossed nicols. B2.
Red channel subtracted from green channel, using Adobe Photoshop’s “Difference”
blending mode and adjustment of levels.
Click on image to toggle between A1,
B1 and A2, B2.
