Britannica
Sources used in this answer
Which animals are most closely related to sloths?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
sloth
Juvenile three-toed sloth (Bradypus) climbing a tree branch.
Sloths are most closely related to anteaters, with which they share the order Pilosa. Together, sloths and anteaters are grouped with armadillos to form the magnorder Xenarthra.123
Members of the Xenarthra lineage are characterized by unique joints in their lower backbone, known as "xenarthrous" vertebrae, which strengthen the hips and lower back. Additionally, these animals share physiological traits such as low metabolic rates and cooler body temperatures compared to other mammals of similar size. While modern xenarthrans are restricted to the Western Hemisphere, their evolutionary history includes various extinct relatives, such as the ground sloths and glyptodonts.32