In 1986, Robert Bakker made the ceratosaurs, famous for their nasal horn, the first of a major, more advanced group of theropods, the Neotheropoda.8 This is because he thinks they have the double-jointed lower jaws (Walking dinosaur costume). However, having looked over the best existing skull, I do not think they did. Instead, ceratosaurs were very primitive theropods because they retained a very coelophysian-like anatomy(Animatronic dinosaur).
They are a bit more advanced than coelophysians in having more slender shoulder blades, longer ilia, bigger outer processes near the femoral head, and somewhat taller ankle processes.
The next more derived group is the intertheropod, which are good-sized theropods with features that place them between the basal and the advanced theropods. This group includes the heavily built megalosaurs and the normally buitt eustreptospondylians and metriacanthosaurs. These advanced paleotheropods are more derived than the coelophysians and ceratosaurs because of their still more slender shoulder blades, larger outer femoral process, vertical pubes with growing boots, and narrower central cannon bone (Realistic dinosaur costume). The short-forearmed megalosaurs are rather strange theropods, especially the South American abelisaurs and noasaurs. This shows that they had left the mainstream of theropod evolution. Small .f/ocsaurus paralleled some protobirds by developing a special killing claw on the second toe.