This lineated frog has two “fibrocartilagenous elements” by its knee joint… but are they kneecaps?Bert Willaert/Naturepl.comBy Andy CoghlanFrogs legs have sprung a big surprise – contrary to textbook biology, they have primitive kneecaps. The kneecaps are made of dense, fibrous cartilage rather than bone, and appear to be much better suited to soaking...