A giraffe's skinny legs look like they could collapse at any second under the animal's immense weight.
But new research has revealed what makes their stems sturdy enough to support a 2,200-lb. (1,000 kilograms) body. Besides having elongated leg bones, giraffes are equipped with pieces of connective tissue, called suspensory ligaments, to help hold them up.
Relying on a suspensory ligament — which is made of elastic tissue, not muscle — allows giraffes to conserve energy: They don't have to engage as much muscle to support their weight. The researchers also think the ligament prevents the foot joints from overextending and collapsing./livescience/