History’s Mysteries: Identifying Fossil Tree Species

Last week, Forest Products Laboratory (FPL) botanist Mike Wiemann wowed the crowd at Science Friday (an informal monthly gathering of FPL folk) with stories of identifying ancient trees that had literally turned to stone.

Fossil tree in Ethiopia.

Fossil tree in Ethiopia.

Wiemann traveled to Ethiopia to collect samples from the fossil forests there to see if he could determine the trees’ species. The fossil stumps were dated at a stunning 27 million years old, and Wiemann wondered what, if anything, would be left of the cell structure for him to examine. What he found was nothing short of incredible.

Low resolution cross-section of fossil tree sample.

Low resolution cross-section of fossil tree sample.

Microscope slides created from the samples Wiemann took showed enough detail for him to identify the tree’s nearest living relative. He was able to compare the fossil slides with samples from FPL’s wood collection to determine the species: Antiaris toxicaria.

High resolution cross-section of fossil tree sample.

High resolution cross-section of fossil tree sample.