Quick Answer. When a solid turns into a liquid it is called fusion, more commonly referred to as melting. When a material moves from one state of matter into another it is called a phase transition. Fusion is just one of approximately different states that matter can phase through.
Before the dinosaurs, there were Triops. Fossil Triops more than 200 million years old have been discovered. By comparison, dinosaurs date back only about 60 million years...just 'youngsters' in terms of geologic time. Triops are distant relatives of trilobites. Triops means three-eyes while the name trilobite means three lobed or three segments.
Birds are descendants of the dinosaurs, and are therefore archosaurs. Champsosaurs became extinct in the Oligocene. Crocodilians (which include all modern crocodiles, alligators, and gharials) and birds flourish to-day, and it is generally agreed that birds have the most species of all air-breathing vertebrates. The hip sockets faced sideways but the knobs on the femurs were at right angles to the rest of the femur, which therefore pointed downwards. 2  Dinosaurs evolved from archosaurs with this hip arrangement. 3  The hip sockets faced downwards and the knobs on the femurs were in line with the femur.