Tetrapodomorpha is a clade of vertebrates, consisting of sarcopterygians with a number of features of tetrapods. Primitive forms, like Tiktaalik, have been referred to as "fishapods" by their discoverers, since they were half-fish half-tetrapods, at least in appearance. Tetrapodomorpha contains the true tetrapods and several groups of related lobe-finned fishes, collectively known as the osteolepiforms. Among the characters defining the tetrapodomorphs are modifications to the fins, notably a humerus with convex head articulating with the glenoid fossa (the socket of the shoulder joint).