Jack D. Griffith of the University of North Carolina at Chapel Hill found the cellulose microfibers in samples he took from ancient salt deposits buried beneath an underground nuclear waste repository near Carlsbad, N.M., the university said in a release.

The findings are published in the journal Astrobiology.

"The age of the cellulose microfibers we describe in the study is estimated to be 253 million years ... ," Griffith said in a statement. "It makes these the oldest native macromolecules to date to have been directly isolated, visualized and examined biochemically."

Prior to this discovery, the oldest evidence of biological material from fragments of ancient protein was dated at 68 million years.

The cellulose microfibers were found in the U.S. Department of Energy's Waste Isolation Pilot Plant nuclear waste repository, built more than 2,000 feet below the surface in rooms excavated from the salt deposits.