Castoridae Hemprich 1820

Castoridae Hemprich 1820, Grundriss Naturgesch.: 33.

Synonyms: Castorini Giebel 1855; Castorida Haeckel 1866; Castoroidea Gill 1872 .

Genera: 1 genus with 2 species:

Genus Castor Linnaeus 1758 (2 species)

Discussion: Generally placed as the sole extant family of the sciurognath infraorder Castorimorpha (Carleton, 1984; McKenna and Bell, 1997), beavers are probably most closely allied to geomyoid rodents ( Geomyidae + Heteromyidae; see Murphy et al., 2001 a; Montgelard et al., 2002). There are a number of additional fossil synonyms that do not refer to crown-group beavers (McKenna and Bell, 1997).