Tree fossils yield ancient chemicals


CORVALLIS - Researchers at Oregon State University have discovered some natural "terpenoids" in an undegraded form in fossils about 50 million years old - the first time that this type of organic compound has ever been found intact in such an ancient source.

The findings will be published Friday in the journal Science.

Terpenoids are a group of organic natural products that are common in nature in both liquid and solid forms. They are found in such things as natural resins and tree sap, and are often used in making perfumes. The conifer tree cone fossils containing the prehistoric terpenoids were found in Germany, where they had somehow become encased in a resin that made them highly impervious to water, air and the normal chemical degradation that would happen over time.

"This is unique, not something we've ever found before in fossils," said James White, a distinguished professor of chemistry at OSU. "Usually in fossils you might find only scattered remains of these chemical compounds, not the intact terpenoid. It's sort of like finding a body with all its clothes on instead of just a skeleton."

The discovery of these ancient terpenoids will allow scientists to obtain a precise chemical signature of the trees from which they came, White said, and will be valuable in tracing the evolutionary history of plant species that are still around today.

In continued research, the scientists hope to find even older fossils with intact terpenoids, perhaps dating back 150 million years to the Cretaceous period, or even earlier.

The fossils encased in protective resin, White said, are conceptually similar to the insect remains that have been found in ancient amber, which is a semi-precious stone originating from tree sap. In some of those insects ancient DNA dating from the time of the dinosaurs has been found in degraded forms. Other investigators on this research were Bernd R. T. Simoneit with the College of Oceanic and Atmospheric Sciences at OSU, and Angelika Otto of Frankfurt, Germany.