After McKenna & Bell, 1997 and Alroy, 2002-2005

Neatocastor Korth, 1996
        †Stenofiber Douglass, 1901 (in partim)
        †Monosaulax; Stirton, 1935 (in partim)
        †Monosaulax; Black, 1961 (in partim)
        †Steneofiber; Xu, 1994 (in partim)

        †Neatocastor hesperus (Douglass, 1901)
            †Steneofiber hesperus Douglass, 1901
            †Monosaulax hesperus (Douglass); Stirton, 1935
            †Monosaulax hesperus (Douglass); Black, 1961
            †Steneofiber hesperus Douglass; Xu, 1994
            †Neatocastor hesperus (Douglass); Korth, 1996a
            †Neatocastor hesperus (Douglass); Hayes, 2000
            †Neatocastor hesperus (Douglass); Tabrum & Nichols, 2001
          including:Steneofiber complexus Douglass, 1901
              = Monosaulax complexus (Douglass); Stirton, 1935
              = †Neatocastor hesperus (Douglass) Korth, 1996a
              = †Neatocastor hesperus (Douglass); Hayes, 2000
              = †Neatocastor hesperus (Douglass); Tabrum & Nichols, 2001

Reference(s):