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Arctocyonides is an extinct genus of arctocyonid "condylarth" mammal that lived iin the United Kingdom, Belgium, France and Germany from the Paleocene to the Eocene.


Van Valen (1978) and Russel (1964) found Claenodon is a junior synonym of Arctocyonides. Comparison of Arctocyon ferox and Arctocyon and Arctocyonides spp. show North American species are much closer to A. primaevus. Arctocyonides has square and rectangular upper and lower molars, with more developed conules in the upper molars. The lower teeth are more bunodont, which is not lost in worn specimens. The upper molar cingula and premolars are narrower. All these characteristics differentiate Arctocyonides from Arctocyon. However, Albuquerque (2004) finds Claenodon is more likely a synonym of Arctocyon[1].

A cf. Arctocyonides was recovered marine deposists in the Selandian-aged Orp Sand Member, Heers Formation[2].


  • A. arenae[3]
  • A. jeffreyi[3]
  • A. trouessarti[3]
  • A. weigelti[3]


Note: references appear as superscript numbers such as: [1].