Photo: Hind Limb Buds on Dolphins An embryo of a Spotted Dolphin in the fifth week of development. The hind limbs are present as small bumps (hind limb buds) near the base of the tail. The pin is approximately 1 inch (~2,5 cm) long. Photo used with permission through the GNU Free Documentation License Version 1.2 http://en.wikipedia.org/wiki/Image:Dolphin_embryo.jpg