Amber Flea Fossil May Contain Ancient Black Death Ancestor

Posted on October 1, 2015

Flea trapped in amber 20 million years ago

Researchers have discovered a 20-million-year-old fossil of a flea entombed in amber. The flea contained bacteria that may be an ancestor of the Black Death. Researchers believe it may be the oldest known strain of the bubonic plague.

Researchers still need to conduct more tests to see if the bacteria is definitely related to the plague bacteria, Yersinia pestis. If it is related it means the deadly bacteria predates the human race. The image below contains an arrow pointing at bacteria on the proboscis of the ancient flea preserved in amber

Bacteria on a flea trapped in amber 20 million years ago

The researchers say the size, shape and characteristics of the bacteria are consistent with modern form of the bacteria. The findings conflict with modern genomic studies that indicate the flea-plague-vertebrate cycle evolved in the past 20,000 years, rather than 20 million years ago.

George Poinar, Jr., the study author and entomology researcher in the College of Science at Oregon State University, says in a statement, "Aside from physical characteristics of the fossil bacteria that are similar to plague bacteria, their location in the rectum of the flea is known to occur in modern plague bacteria. And in this fossil, the presence of similar bacteria in a dried droplet on the proboscis of the flea is consistent with the method of transmission of plague bacteria by modern fleas."

Poinar also says, "If this is an ancient strain of Yersinia, it would be extraordinary. It would show that plague is actually an ancient disease that no doubt was infecting and possibly causing some extinction of animals long before any humans existed. Plague may have played a larger role in the past than we imagined."

A research paper on the findings were published in the Journal of Medical Entomology.

Photos: George Poinar, Jr., courtesy of Oregon State University