Early evolution of non-avian dinosaurs during the pre-Jurassic episode

چکیده

Dinosauria represents an effective group of Mesozoic terrestrial vertebrates which experienced the exceptional evolutionary processes to establish a diverse, widespread faunal lineage across nearly 160 million years of the Earth's geologic history. Early evolution of non-avian dinosaurs has been continuously focused by recent paleontological research, showing a complex and even sometimes confusing type of biological developments. This study presents a brief report on early evolution of non-avian dinosaurs at the pre-Jurassic geologic episode. The methodology process was performed by comparative analyses on the current publications to provide a descriptive summery of organized data. Fundamentally, it is demonstrated that the main concepts of early dinosaur developmental history have focused on major biological and environmental constraints which forced the group to a complex route of evolution and biodiversification. As the keystones of relevant paleontological approaches, stratigraphic analyses and continuous biological investigations are crucial items in order to access the supportive information on pre-Jurassic non-avian dinosaurs.