Parastrapotherium is an extinct genus of South American land mammal that existed from the Late Oligocene (Deseadan SALMA) to the Early Miocene (Colhuehuapian SALMA). The genus includes some of the largest and smallest known astrapotherians, but has no generally recognized description.
The genus was first described by Amagehino in 1895. He distinguished it from the Santacrucian (late Early Miocene) Astrapotherium based on the greater number of upper and lower molars. Although later researchers disagreed and concluded that Ameghino based his conclusion on very fragmentary materials, they mostly agreed to distinguish the genus from other groups of astrapotherians. In the mandibular canine of Parastrapotherium, the microstructure of the tooth enamel is characterised by vertical decussation with enamel prism zones bending in an undulatory pattern.
The following species have been recognised:
Fossils of Parastrapotherium have been found in:
The microstructural details of its long bones indicate that Parastrapotherium was specialised for graviportal locomotion.