After McKenna & Bell, 1997, with Recent species from Nowak, 1991

    Hydrochaeris Brunnich, 1772
        Hydrochoerus Brisson, 1762
        Hydrochaerus Erxleben, 1777
        Hydrochoenus Gray, 1821 (lapsus calami?)
        Hydrocherus F. Cuvier, 1829
        Hydrochoerus Wagler, 1830
        Hydrochoeris Allen, 1916
        Hydrocheirus Hollande & Batisse, 1959
        Hydrochaeris Brunnich; McKenna & Bell, 1997
        Capibara Moussey, 1860
        Capiguara Liais, 1872
      including:Xenohydrochoerus Rusconi, 1934

        †Hydrochaeris holmesiHydrochaeris gaylordi MacPhee, Singer & Diamond, 2000

        Hydrochaeris hydrochaeris (Linnaeus, 1758)
          including?:
            Hydrochaeris isthimus Goldman, 1912

        ?Hydrochaeris isthimus Goldman, 1912
            =? Hydrochaeris hydrochaeris (Linnaeus, 1758)

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