Most freshwater turtles have longer legs and webbed feet. Sea turtles have legs shaped like long paddles, with flippers instead of feet. The hip bones and shoulder bones of the turtles, unlike those of any other animal, are inside the ribcage. This unusual feature enables most kinds of turtles to pull their legs inside their shell. The species that are unable to withdraw their legs cannot do so because the shell is too small.
Turtles have a well-developed sense of sight and of touch.
Scientific experiments indicate that they also have a good sense of smell, at least for nearby objects. A turtle can hear low-pitched sounds about as well as a human being can. The Life of A Turtle Young. Turtles hatch from eggs, which are fertilized within the female's body. One mating can result in the fertilization of all the eggs of a female for several years.