Trace fossils are the marks or imprints left by often unknown animals. We have a separate nomenclature to describe them, ichno-genus and ichno-species. The body fossil and trace fossil are virtually never found together,
Cruziana is the genus name given to trilobite tracks by d'Orbigny in 1842, in honour of the South American liberator Andres de Cruz.
Despite this early identification, trace fossils were poorly studied early on, as they seemed to have little use in stratigraphy.
In fact they were to remain little more than curiousities for a long time.