| Zoophycos trace fossils from lower Cambrian portion of the upper Precambrian-lower Cambrian Wood Canyon Formation, Inyo County, California. This is the oldest Zoophycos yet discovered in the fossil record--from the base of the middle member of the Wood Canyon Formation--only a few feet above the first occurrence of the ichnofossil Treptichnus pedum, which presently defines the worldwide base of the Cambrian Period (and, hence, the beginning of the Paleozoic Era), 541 million years ago. Zoophycos is a trace fossil created by a presumed deposit feeder. Image courtesy a specific scientific document. |