Kitasato Shibasaburō
"Y. pestis", the first known species, was identified in 1894 by A.E.J. Yersin, a Swiss bacteriologist, and Kitasato Shibasaburō, a Japanese bacteriologist. It was formerly described as "Pasteurella pestis" (known trivially as the plague-bacillus) by Lehmann and Neumann in 1896. In 1944, van Loghem reclassified the species "P. pestis" and "P. rondentium" into a new genus, "Yersinia". Following the introduction of the bacteriological code, it was accepted as valid in 1980.