Phylogeny and evolutionary stages of Dinosauria

New suggesti ons are offered con cern ing the phyl ogeny of the dinosaurs, based on the Chinese m aterials as well as tho se fr om other p arts of the w or ld . The t wo dinosaur orders, Saurischia and Ornith isch ia, differ ed in tempo of evolution. The Saurischia include four evolution ary branches (Plateosauria, S auropoda, Coe lu r osauria , Carnosauria ) or igi na ting from differe n t ps eudosuchians in the L at e Trias sic, most of which exte n d to the Late Cr etac eous. Ornithischia also evolved f rom dif ferent pseudosuchians in the Late Triass ic an d include three evolu ti on ary branches: ornithopoda, P achycephalosauria and Armatosauria n . suborder. Four m ain st ages can be dis t inguished in the e volution of all dinosaurs. Wi thin Ornithischia one new su bor der Arm atosauria is erected and eigh t n ew superfam llies: Tianc hungosa uroidea, Ch aoyoungosa u roi dea, Psit t acosau r oidea, Pachycephalosaur oidea, Scelldosauroidea, Stegosauroide a, Ollgosacr alosa u r oidea and Polys acralosauroid ea are in t r oduce d..