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. The more or less uniform burrow diameter in the Chattanooga Shale suggest that the burrowers moved in a smooth, continuous fashion. Because such burrows are typically constructed in a firm substrate, the misidentification will lead to a mistaken assessment of substrate conditions.