In the central portion of the picture is a horizontally oriented earthworm trace that shows how peristalsis affects burrow diameter. The worm was moving from left to right, the consistency was that of buttermilk, and we see the development of swirl like features. The hole in the bottom right half of the picture is due to a worm that got stuck and then decayed. Decay processes produced the fuzzy gray halo in the plaster adjacent to the worm. The image is 120mm wide.
Percentages indicate simulated water content of the substrate.
Colors of the scan were reversed for better contrast. Percentages indicate calculated water content of the shale. Percentages indicate calculated water content of the shale. Percentages indicate calculated water content of the shale. Experimental structures were influenced by the consistency of the substrate, the morphology of the worms, and the type of locomotion.