An alternate, less widely accepted hypothesis for the origin of bioturbation exists. The trace fossil Nenoxites is thought to be the earliest record of bioturbation, predating the Cambrian Period. The fossil is dated to 555 million years, which places it in the Ediacaran Period. The fossil indicates a 5 centimeter depth of bioturbation in muddy sediments by a burrowing worm. This is consistent with food-seeking behavior, as there tended to be more food resources in the mud than the water column. However, this hypothesis requires more precise geological dating to rule out an early Cambrian origin for this specimen.
