It has happened before.

The former oldest tree, Prometheus, was cut down in 1964 in Great Basin National Park in Nevada by a graduate student researching the effects of climate change on receding glaciers by measuring their influence on the size of the rings of ancient pine trees. There are a few accounts of what happened. The student, Donald R. Currey, said in a PBS documentary that the normal approach to coring a tree was not working, so he cut it down with the help of some foresters. Members of the forest service said he got his drill bit stuck in the tree, and he and the foresters cut it down to remove his tool. Only after the tree had been felled and he counted its rings did he realize that he had just slain the oldest known tree on Earth, which was then a wizened 4,900 years old.

Methuselah was nearly 4,790 by the time anyone realized just how exceptional it was. Edmund Schulman, a scientist with the University of Arizona’s Laboratory of Tree-Ring Research, calculated its age in 1957.

Of course, it’s not possible to say that any given tree is definitely the oldest tree on Earth because not all trees have been analyzed in this way. But dendrochronologists — people who study the ages of trees — have examined at least tens of thousands of trees around the world since then, and none have been confirmed to be as senior as Methuselah.

To pin down the date (or era) of Methuselah’s birth, Dr. Schulman took several samples from the tree using a tool called an increment borer and matched up the ring patterns from each sample “to travel back in time,” said Matthew Salzer, a research associate at the Laboratory of Tree-Ring Research. Because bristlecone pines like Methuselah do not have cylindrical trunks — they are twisted by the wind into natural sculptures — taking samples from different parts of the tree can give an estimate of the tree’s age, Dr. Salzer said.