Abstract

In the past two decades, specimens of eight genera of stegosaurs from the Early Jurassic to the Late Cretaceous have been discovered in Asia. These include Tatisaurus, Huayangosaurus, Chialingosaurus, Chungkingosaurus, Tuojiangosaurus, Monkonosaurus, Wuerhosaurus, and Dravidosaurus. This material reveals that stegosaurs arose from a Late Triassic small ornithopod – a fabrosaur or heterodontosaur – and that the birthplace of this group is probably eastern Asia. Tatisaurus, originally referred to the Ornithopoda, is transferred to the Stegosauria. Dravidosaurus is the youngest stegosaur known. A classification of the stegosaurian dinosaurs is presented, as well as a phylogenetic interpretation.

Introduction

Stegosaurian remains are known from Mesozoic continental deposits of all the continents except Australia, South America, and Antarctica (Fig. 19.1). The first description of a stegosaur was that of Craterosaurus, found in the Potton sands (Lower Cretaceous) near Potton, England. It was described by Seeley in 1874, but it was Nopcsa (1912) who recognized it as part of the neural arch of a stegosaurian dinosaur. From the middle of the last century, the study and collection of dinosaurs centered in North America. The first stegosaurs from North America were described by Marsh in 1877, from Colorado and Wyoming. Complete stegosaurian skeletons were collected in Utah, and less complete material in Oklahoma. Outside North America and Asia, stegosaurs have been discovered in Africa and Europe (Hennig 1915; Galton 1985).