another late slowski! sloths are my ultimate favorite animal, although i prefer the two-toed variety to the three-toed ones. three-toed sloths have a pretty excellent spine adaptation, however! unlike hooved mammals, their spines are curved and very flexible, and the fact that they have nine cervical (neck) vertebrae means they can rotate their heads 180°! most other animals have only seven, and my preferred sloth species (two-toed) has a mere six.