4b. Two families of sloths exist commonly in Central and South America (two-toed and three- toed sloths. Is the skeletal specimen found in class a two-toed or three-toed sloth? (.25 pt) Solution Kangaroos have short forelimbs, this is because short arms faciliate the easy survival within the mother\'s pouch soon after birth. On the other hand the hindlimbs development is not constrained in the pouch, so they have long hindlimbs. As their forelimbs are short and they cannot hop fast with this, they develop long hindlimbs to compensate for the short forelimbs. The long hindlimbs are needed for fast hopping..