There are three main forms of trace fossils associated with trilobites: "Rusophycus", "Cruziana" and "Diplichnites"—such trace fossils represent the preserved life activity of trilobites active upon the sea floor. "Rusophycus", the resting trace, are trilobite excavations involving little or no forward movement and ethological interpretations suggest resting, protection and hunting. "Cruziana", the feeding trace, are furrows through the sediment, which are believed to represent the movement of trilobites while deposit feeding. Many of the "Diplichnites" fossils are believed to be traces made by trilobites walking on the sediment surface. Care must be taken as similar trace fossils are recorded in freshwater and post-Paleozoic deposits, representing non-trilobite origins.