The skull was generally low and elongated in shape, with greatest width at the anterior and posterior bases of the zygomatic arch respectively.

The joint surfaces of the back of the head for connection with the cervical spine stood out prominently to the rear and were hemispherical in shape.

Similar to Eremotherium, they sat relatively low on the skull just above the palate level, which differs from Megatherium or Pyramiodontherium with their high-set condyles, among other things .

The anterior edge of the posterior palatal hole reached the fourth to fifth molar-like tooth in Proeremotherium, and continued further back in Eremotherium.

They showed the two sharp ridges perpendicular to the longitudinal axis of the tooth, which are characteristic of Megatheria, with a deep V-shaped indentation in between.

In the Falcón Basin, an approximately 36,000 km² large depression, deposits of the Urumaco sequence are exposed, which date from the Lower Miocene to the Pliocene and thus cover a period of around 20 million years.

The rock unit is composed of dark-colored, cross-bedded sandstones and lighter-colored limestones and was formed in the transition from the Upper Miocene to the Lower Pliocene about 6 million years ago.

Pseudoprepotherium, Magdalenabradys, Eionaletherium and Urumacotherium have also been documented, all representing mylodontids, while Urumacocnus and Pattersonocnus belong to the Megalonychidae.

In addition to the skull of the sloth genus, remains of rodents such as guinea pig relatives, but also armadillos, representatives of the Pampatheriidae and Glyptodontinae and South American ungulates were found here .

[9][10][2] The two known skulls of Proeremotherium show individual variations, such as the course of the temporal lines or the length of the crown crest, but also the insertion of the zygomatic arch and the orientation of the joints of the occipital bone.

This classic perspective is opposed to molecular genetic and protein-based investigations, which reveal an additional third lineage with the Megalocnoidea .

The basis was the skull from the Codore Formation in the Falcón Basin of Venezuela, which thus acts as a holotype (specimen number AMU-CURS 126).

[14] Eremotherium Megatherium Proeremotherium Pyramiodontherium Anisodontherium Diabolotherium Megathericulus Planops Prepotherium Prepoplanops Proeremotherium lived in a tropical environment in an area of northern South America that was left relatively untouched by the Great American Interchange, the only non-native species of mammal known in the area of the Falcón Basin being the procyonid Cyonasua[15] and Chapalmalania, and, potentially, a Camelidae still unassigned to a specific genus.

[15] It coexisted with pampatheres such as Holmesina and Plaina, Proterotheriidae, the glyptodont Boreostemma, the Dasypodidae Pliodasypus and the notoungulate Falcontoxodon, as well as several species of caviomorph rodents such as Caviodon, Hydrochoeropsis, Marisela and Neoepiblema, and the crocodile Crocodylus falconensis.