West Indian manatees are large aquatic mammals that live in rivers and near shore estuaries, especially in Florida. They have two flexible front flippers with three or four toenails, similar to elephant toenails. Though they lack hind limbs, manatees have vestigial pelvic bones, as shown in the diagram

Respuesta :

So maybe they share a common ancestor, the also have homologous structures, same structure different function.

Answer:

The existence of pelvic bones and toenails in manatees and elephants suggests that manatees and elephants evolved from the same land animal.