Acta Palaeontologica Polonica

Phylogeny and evolutionary stages of Dinosauria

Zhao Xijin (Chao Shichin)

Acta Palaeontologica Polonica 28 (1-2), 1983: 295-306

New suggestions are offered concerning the phylogeny of the dinosaurs, based on the Chinese materials as well as those from other parts of the world. The two dinosaur orders, Saurischia and Ornithischia, differed in tempo of evolution. The Saurischia include four evolutionary branches (Plateosauria, Sauropoda, Coelurosauria, Carnosauria ) originating from different pseudosuchians in the Late Triassic, most of which extend to the Late Cretaceous. Ornithischia also evolved from different pseudosuchians in the Late Triassic and include three evolutionary branches: Ornithopoda, Pachycephalosauria and Armatosauria n. suborder. Four main stages can be distinguished in the evolution of all dinosaurs. Within Ornithischia one new suborder Armatosauria is erected and eight new superfamllies: Tianchungosauroidea, Chaoyoungosauroidea, Psittacosauroidea, Pachycephalosauroidea, Scelidosauroidea, Stegosauroidea, Oligosacralosauroidea and Polysacralosauroidea are introduced.

Key words: Dinosauria, evolution, phylogeny.

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