They were bird hipped form of dinosaurs having their pubis bone pointing down and forming towards the rear1. It is further to sub orders Thyreophora, Ornithopoda, and Marginocephalia1.
Dinosaurs existed between the Mesozoic period which occurred around 250 million years ago (ma). Mesozoic era is divided into three periods namely:
Triassic (248.2 Ma to 205.7 Ma)
Jurassic (205.7 Ma to 144.2 Ma)
Cretaceous (144.2 Ma to 65.5 Ma) 4