The termite was found in a chunk of amber excavated in 2001 from a mine in Myanmar, formerly known as Burma, said George Poinar, a researcher at Oregon State University.
The termite, which lived during the Early Cretaceous period in the age of the dinosaurs, landed in the amber with a wounded abdomen, from which spilled protozoa the termite needed to digest wood.
This mutualism, or symbiotic relationship in which two species help each other, has enabled the termite to become one of the most successful insect groups in the world, with about 2,300 known species.
"These protozoa would die outside of the termite, and the termite would starve if it didn't have the protozoa to aid in digestion," Poinar said. "In this case they depend on each other for survival."
Poinar's findings have been published in the most recent issue of Parasites and Vectors, a professional journal.