Like all of the Antillean sloths, Acratocnus was formerly thought on the basis of morphological evidence to be a member of the family Megalonychidae, which was also thought to include Choloepus, the two-toed tree sloths.
Like all of the Antillean sloths, Acratocnus was previously assumed to be a part of the family Megalonychidae, which also included Choloepus, the two-toed tree sloths.