Astrapotherium

Astrapotherium ("Great Lightning Beast") is an extinct South American mammal which vaguely resembled a cross between a small elephant, and a very large tapir. This peculiar-looking animal was unrelated to modern elephants, and was, instead, related to other extinct South American ungulates.

Description
Astrapotherium had an elongated body, with a total length of about 2.5 metres (8.2 ft), a weight of nearly 1000 kg, and relatively short limbs. It had small, plantigrade, feet, and the hind limbs were significantly weaker than the fore limbs. Its four canine teeth were elongated to form short tusks, and it had broad protruding lower incisors, which likely ground against a horny pad in the upper jaw, as in many modern ruminants.[1]

The nostrils were placed high on the head, which might indicate the presence of a trunk, but could equally be due to other reasons, such as an inflatable nasal cavity.

Paleobiology
The animal was probably at least partially aquatic, living in shallow water and feeding on marsh plants in a similar manner to a modern hippopotamus.