Various synapomorphies for Theropoda have been proposed based on which taxa are included in the group. For example, a 1999 paper by Paul Sereno suggests that theropods are characterized by traits such as an ectopteryg… 詳細

During the late Triassic, a number of primitive proto-theropod and theropod dinosaurs existed and evolved alongside each other.
The earliest and most primitive of the theropod dinosa… 詳細