[5] The genus probably arose from Eurasian Miocene hyenas such as Thalassictis or Lycyaena, with C. borissiaki being the oldest known representative.

[4] Chasmaporthetes was named (from chasm and the Greek πορθευτής (portheutes), "destroyer, ravager") by Hay (1921), who noted that the name meant that the North American species, Chasmaporthetes ossifragus (the type species) possibly saw the beginning of the Grand Canyon.

[10] A study on the genus' premolar intercuspid notches indicated Chasmaporthetes was likely hypercarnivorous rather than durophagous as its modern cousins (excluding the aardwolf) are.

[11] In Europe, the species C. lunensis competed with the giant cheetah Acinonyx pardinensis, and may have preyed on the small Bourbon gazelle (Gazella borbonica) and the chamois antelope (Procamptoceras brivatense).

[10] The North American C. ossifragus was similar in build to C. lunensis, but had slightly more robust jaws and teeth.