Olympic Marmot - Taxonomy

Taxonomy

American zoologist and ethnographer Clinton Hart Merriam first described the Olympic marmot in 1898 as Arctomys olympus, from a specimen collected on the Sol Duc River. The species name olympus (Olympic in Greek) was given because this species is native to the Olympic Peninsula of Washington state. Now the species is classified with all other marmots in the genus Marmota. Zoologist R. L. Rausch classified the Olympic marmot and other North American species as subspecies olympus of Marmota marmota (which now only includes the Eurasian Alpine marmot) in 1953, but it has usually been treated as a distinct species, a treatment supported by taxonomic reviews starting with that of zoologist Robert S. Hoffmann and colleagues in 1979. Within Marmota, the Olympic marmot is grouped with species such as the hoary marmot in the subgenus Petromarmota. Within this grouping, mitochondrial DNA analyses suggest that the Olympic marmot is the most basal species. The Olympic marmot is thought to have originated during the last glacial period as an isolated relict population of the hoary marmot in the Pleistocene ice-free refugia. The Olympic marmot deviates from the typical Petromarmota marmots in the large shape of its mandible (jawbone), in differences of the dorsal (back) region, and having 40 chromosomes instead of 42, all of which are characteristics that resemble the subgenus Marmota. The significant difference of the Olympic marmot's jawbone from the typical Petramarmota is also evident in the Vancouver Island marmot (M. vancouverensis), which evolved separately, but also occurs in a restricted range with a small population.