Abstract
A spectrum of gradational random patterns simulating late Proterozoic trace fossils such as Helminthoidichnites, Torrowangea, and intermediate types was produced, using only two variables: angular deviation per unit length of trace and randomly determined turning directions. Loop development can be a random feature and thus of uncertain taxonomic significance. Plots of local trace orientation versus distance along trace (goniograms) and derivative graphs provide quantitatively efficient ways of presenting multiple data on horizontal trace fossils. By comparison, graphs for Gordia show strong nonrandom signals.