However, this fossil also appears in older rocks than the locality which officially marks the start of the period.
The earliest fossil of fungi appears about 460 million years ago in the Ordovician period.
The fossils appear to have been preserved when water created a sedimentary deposit in an earlier version of the cave.
The first fossils of eyes appeared during the lower Cambrian period, about 540 million years ago.
In addition, other fossils from the same deposit appear to lack internal nuclei.
These fossils appear to belong to the crown group, and illustrate that sipunculans have changed little since the early Cambrian.
Spectacular fossils from Doushantuo in China appeared to resolve this issue.
In the theoretical year of life, shelled fossils do not appear until early November.
Dr. Rijsdijk said that the fossils appeared to have formed in a forest lake.