|Name Translation||Great Lightning Beast|
|Period||Late Oligocene-Mid Miocene of the Cenozoic Era|
|Length||2.5 metres (8.2 feet) long|
Astrapotherium was a genus of large ungulate from the late Oligocene - middle Miocene of South America. They are the most well-studied members of detachment Astrapotheria. Astrapotherium was a rather large animal, the length of their bodies reached 288 cm, height was 137 cm and weight is likely as high as 600–800 kg. Its head was large enough relative to the body size, its skull length was 65 cm and for Astapotherium marked sexual dimorphism which is expressed primarily in the difference in size, shape and configuration of the canines of males and females.
In males, the lower canines were relatively longer, thicker and forward. In females they are shorter, thinner and relatively longer bend outward. These unusual ungulates are likely to gravitate to water habitats, however, not included was the possibility of living in the humid lowland forests. They had a strong elongated body and hind legs, and given the massiveness of these animals were relatively weak. A small but powerful five-fingered foot was suitable for walking on swampy, soft ground. According to some researchers, this may indicate that Astrapotherium spent much time in the water whereas on land, creatures with such a disproportionate physique almost certainly would have been quite awkward walking on land.
Astrapotheriums canines could be used to remove the bark, branches and pulling out and grabbing roots. When the branches were growing on the banks of plants for Astrapotherium to bend down and attracted to its mouth with a trunk and tusks. Causes of extinction of Astrapotherium, as the other members of the order, remain unknown. Rather, they were associated with changes in the environment, destroyed the usual habitat of these sensitive animals. Not excluded by competition from other South American ungulates.