Myocastor Kerr 1792

Myocastor Kerr 1792, in: Linnaeus, Anim. Kingdom: 225.

Type Species: Mus coypus Molina 1782

Synonyms: Mastonotus Wesmael 1841; Myopotamus Geoffroy 1805; Potamys Desmarest 1825 .

Species and subspecies: 1 species with 4 subspecies:

Species Myocastor coypus (Molina 1782)

Subspecies Myocastor coypus subsp. coypus Molina 1782

Subspecies Myocastor coypus subsp. bonariensis Geoffroy 1805

Subspecies Myocastor coypus subsp. melanops Osgood 1943

Subspecies Myocastor coypus subsp. sanctaecruzae Hollister 1914

Discussion: Patterson and Pascual (1968 b:6) included Myocastor and several fossil forms as the subfamily Myocastorinae of the Echimyidae . Based on sequence data, the sister taxon of Myocastor appears to be Capromys (Leite and Patton, 2002) . Although this sister taxon relationship is well supported in both parsimony and maximum likelihood analyses (Leite and Patton, 2002), potential problems including taxon bias and long branch attraction have not been fully addressed.