Fossils of the genus were found at the coastal Piedra Escrita site and the Andean Casa del Diablo cave.

The joints for the cervical vertebrae pointed slightly downwards and were not very prominent, a feature that also occurs in several extinct representatives of the Megalonychidae of the Caribbean islands.

The anterior, spatulate extension of the symphysis, which is typical of numerous sloths, has only been preserved in its posterior part; the full length is unknown.

This is reminiscent of the Megatheriidae but differs from the megalonychids, the frontmost tooth of which is reshaped like a canine, and due to a diastema is separated from the posterior teeth.

The shaft was made of a bone ridge (crista deltoidea), which served as a muscle attachment point and was particularly strong in the middle part.

The length of the last phalanx of the central ray was 6 cm, it was built narrow and slightly curved downwards, which suggests a correspondingly shaped claw.

[4] Diabolotherium is noteworthy for its the long and slender limb bones, which are rarely found in other extinct sloths and usually appear shorter and more robust.

This enables the animals to muster the strength they need to dig, as the triceps that attach here increases the leverage due to the greater length of the appendage.

[2] Purely terrestrial forms have a much shorter extension, but the shortest occurs in today's sloths hanging with their backs down in the branches.

The fact that Diabolotherium was able to climb is supported by the upper joint capsule of the ulna, which circumscribes an open circle of about 105 ° and is therefore extraordinarily wide.

In connection with the position of the spoke pushed in front of the ulna and its circular, upper head, it can be assumed that the forearm could be turned in and out very well and was overall very mobile.

The three equally long rays of the hand in turn indicate an increased ability to grip, which was severely limited in the large ground sloths.

[2] The climbing locomotion of Diabolotherium was originally associated with a solely arboreal way of life, analogous to today's sloths or some forms known from the Lower Miocene of the Santa Cruz Formation.

[2] But since a large part of the more recent finds were discovered in the high altitudes of the Andes, some of which were in caves and rock roofs that were difficult to access today, it is thus assumed that Diabolotherium was much more adapted to climbing in rocky and impassable terrain.