Clues to stages of development in a growing animal come from tooth replacement patterns and timing of suture closure in skull and limb bones.
Life Stages
Juvenile Hemiauchenia are recognized by the same criteria that identify modern young camels (baby teeth, unfused ends of long bones and unfused vertebrae)
Old age individuals are identified by large size, worn teeth, and age-related arthritic bones.
Mortality and Health
Medium to large-sized sized cats, and wolves might have preyed on these small camels.
One isotope study of Smilodongracilis teeth in Florida found this predator had a diet of herbivores such as Hemiauchenia that fed mainly on, wet-climate C3 plants. (Feranec 2002)