FIGURE 4. Reconstruction showing how multiple phases of foraging by an unknown vermiform organism creates Phycosiphoniform looped burrows composed of marginal tube and spreiten (Based upon Wetzel and Bromley 1994; Bromley 1996; Seilacher 2007). Different shades of grey represent distribution of silt-sized (light grey) and clay-sized (dark grey) material. 4.1. Foraging organism creates feeding probes lateral to the marginal tube. 4.2. Successive probes are made until the organism has produced a marginal tube the length of its body. 4.3. Outer margin of the loop is produced by the organism moving along previously produced probes. 4.4. Second loop is stared after the organism body is straight one again. 4.5. For download, zipped animation in EXE (for Windows) and APP (for Mackintosh) file format presenting multiple phases of Phycosiphoniform trace fossil formation.