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).
Hayden (given name) Hayden (given name) Hayden is a given name in the English language. The name is variant of the given name "Haydn", which is derived from the surname "Haydn" in honour of composer Joseph Haydn (1732–1809). The surname "Haydn" originated as a respelling of the nickname "Heiden", meaning "". The name is derived from the Middle High German "heiden", and from the Old High German "heidano". The form "Haydn" was generally considered a masculine given name up until the mid 20th century. The popularity of "Hayden" has been influenced by the popularity of similar-sounding names such as "Aidan", "Braden", "Caden", and