Source: Battle of Bloodmarch Hill, pg(s). 86
Their front limbs are noticeably longer than their hind legs; this, combined with most of their weight resting on their hindlimbs, makes chalicotheriums seem to be upright even when on all fours.
Largely solitary animals, chalicotheriums spend their lives alone unless mated and raising young; one to three pups are born per litter, which ride on their mother's back. Chalicotheriums are highly capable climbers, when they can find a tree large enough to support their considerable weight.