Lower extremity of femur extended. Where the groove ceases laterally the patellar surface is seen to be continued backward as a semilunar area close to the anterior part of the intercondyloid fossa; this semilunar area articulates with the medial vertical facet of the patella in forced flexion of the knee-joint. The tibial surfaces of the condyles are convex from side to side and from before backward. Each presents a double curve, its posterior segment being an arc of a circle, its anterior, part of a cycloid. Lower extremity of femur The lower extremity of femur (or distal extremity) is the lower end of the
Eolambia is expanded forwards. Like the humerus, the femur is bowed, but outwards. However, characteristically, the bottom half of the femur is straight. The fourth trochanter, located halfway down the femur, is vertically tall and triangular, similar to "Probactrosaurus", "Gongpoquansaurus", and other iguanodonts but dissimilar to more basal ornithopods. Like the ulna and radius, the tibia and fibula have straight shafts, and they articulate with each other; a roughened projection on the bottom of the fibula fits between two bulb-like condyles located just behind the cnemial crest on the bottom end of the tibia. The top of the tibia is rough,