pentadactyl limba limb bearing five digits (fingers or toes) which is present in amphibia, reptiles, birds and mammals. The limb is thought to have been evolved largely for life on land and consists of three main parts:
- (a) the humerus (anterior limb) or femur (posterior limb);
- (b) the radius and ulna (anterior), or tibia and fibula (posterior);
- (c) a hand or foot made up of carpals (anterior) or tarsals (posterior), metacarpals or metatarsals and phalanges. In many forms the limb is much modified for activities such as flying, running, or swimming.