Coypu described by Juan Ignacio Molina in 1782 as "Mus coypus", a member of the mouse genus. The genus "Myocastor" was assigned in 1792 by Robert Kerr. Geoffroy Saint-Hilaire, independently of Kerr, named the species "Myopotamus coypus", and it is occasionally referred to by this name. Four subspecies are generally recognized: "M. c. bonariensis", the subspecies present in the northernmost (subtropical) part of the coypu's range, is believed to be the type of coypu most commonly introduced to other continents. Comparison of DNA and protein sequences showed that the genus "Myocastor" is the sister group to the genus "Callistomys" (painted tree-rats).
The Fur Worker Kaufman was another editor of "The Fur Worker" during the 1920s. As of 1925, "The Fur Worker" had a circulation of around 12,000. Issues were sold at 50 cents. In its later years, publication of "The Fur Worker" became more irregular. The publication was suspended between May 1929 and January 1930. Between September 1930 and April 1931 it was issued under the name Fur Workers' Hope. Publication of "Fur Workers' Hope" was discontinued in May 1931. In June 1937 "The Fur Worker" was revived. In the same year the parent under switched its affiliation from the American Federation of Labor