There is no land mammal that can be compared to the size of Balucatherium. As is was stated before, Balucatherium is about as large as a land mammal can become. The closest a land mammal has come to reaching the size of Balucatherium were a few species of Mammoths. 
 
 
 
Mammoths:

- Not even these mammoths, which grew up to twice the size of a modern day elephant, came close to the size of Balucatherium.

 
 
 
 
 
 
 
 
 
 
 
A seen in the picture above the Colombian Mammoth, or Mammuthus columbi, was one of the American mammoths that migrated from Asia to North America during the late Pleistocene. Although a large beast, this mammoth only reached an average height of 3.7m (12 ft.) high. One of the largest mammoths was the species Mammuthus trogontherii which also lived during the Pleistocene. These animals grew to a height of 4.5m (15 ft.) high. 

Mammuthus trogontherii was one of the largest mammals to walk the earth.