The oldest living tree, the Greer lodgepole, was first discovered in the late 1800s, and its remains have remained in a tree ever since.
The lodgepole stands a towering six feet (1.3 metres) tall, reaching a height of nearly eight feet (2.6 metres).
It has been on display at the University of Utah since the 1970s.
But a new research project has found that the lodgepole was in fact an extinct species, which lived during the last Ice Age.
The new research has found it was a tree that once lived in a cave system near Yellowstone National Park, and was buried beneath a layer of rock in the cave system.
“This is the oldest tree in the world that was buried underground and that has remained on the surface of the earth for the last 200 million years,” said Dr Andrew Littrell, who led the study.
A new study has found the Greers lodgepole is an extinct tree that lived during Ice Age, but was buried in a limestone cave systemSource: ABC News/ScienceAlertTopics:science-and-technology,archaeology,united-states