Although it may not be possible to relate those sloths in a familial context, that there is a range of specimen ages does provide new insights in to patterns of growth and development with this species. These specimens helped solidify a pattern of loss in the upper caniniform that was marginally evident in the adults, via vague outlines of avleolar closing.
This same potential for age-related studies exists with the Tarkio sloths as well.

Further sloth history: At the time of Nordenskiold’s discovery, the genus of Mylodon was in the midst of its hefty taxonomic confusion and was currently called Grypotherium. Due to the perceived idea that these sloths were being kept in a coral by humans, the species became known as Grypotherium domesticum. This name has since been synonymized with M. darwini when the last of the taxonomic issues were sorted out between that genus and Glossotherium.