『Abstract
　Dinosaurs were remarkably successful during the Mesozoic and one subgroup, birds, remain an important component of modern ecosystems. Although the extinction of non-avian dinosaurs at the end of the Cretaceous has been the subject of intense debate, comparatively little attention has been given to the origin and early evolution of dinosaurs during the Late Triassic and Early Jurassic, one of the most important evolutionary radiations in earth history. Our understanding of this keystone event has dramatically changed over the past 25 years, thanks to an influx of new fossil discoveries, reinterpretations of long-ignored specimens, and quantitative macroevolutionary analyses that synthesize anatomical and geological data. Here we provide an overview of the first 50 million years of dinosaur history, with a focus on the large-scale patterns that characterize the ascent of dinosaurs from a small, almost marginal group of reptiles in the Late Triassic to the preeminent terrestrial vertebrates of the Jurassic and Cretaceous. We provide both a biological and geological background for early dinosaur history. Dinosaurs are deeply nested among the archosaurian reptiles, diagnosed by only a small number of characters, and are subdivided into a number of major lineages. The first unequivocal dinosaurs are known from the late Carnian of South America, but the presence of their sister group in the Middle Triassic implies that dinosaurs possibly originated much earlier. The three major dinosaur lineages, theropods, sauropodomorphs, and ornithischians, are all known from the Triassic, when continents were joined into the supercontinent Pangaea and global climates were hot and arid. Although many researchers have long suggested that dinosaurs outcompeted other reptile groups during the Triassic, we argue that the ascent of dinosaurs was more of a matter of contingency and opportunism. Dinosaurs were overshadowed in most Late Triassic ecosystems by crocodile-line archosaurs and showed no signs of outcompeting their rivals. Instead, the rise of dinosaurs was a two-stage process, as dinosaurs expanded in taxonomic diversity, morphological disparity, and absolute faunal abundance only after the extinction of most crocodile-line reptiles and other groups.

Keywords: dinosaurs; diversification; evolution; Jurassic; paleontology; Triassic』

Contents
1. Introduction
2. The biological setting for the origin of dinosaurs
　2.1. Archosauria: the ruling reptiles
　2.2. Avemetatarsalia: the “bird-line” of archosaur phylogeny
　2.3. Dinosauria: definition
　2.4. Dinosauria: diagnosis
　　2.4.1. Character states that consistently diagnose Dinosauria
　　　2.4.1. Elongated deltopectoral crest
　　　2.4.1.2. Open acetabulum
　　　2.4.1.3. Temporal musculature extends anteriorly onto skull roof
　　　2.4.1.4. Epipophyses
　　　2.4.1.5. Articulation facet for fibula occupying less than 30％ of the transverse width of the astragalus
　　　2.4.1.6. Femoral fourth trochanter asymmetrical, with distal margin forming a steeper angle to the shaft
　　　2.4.1.7. Posterior process of the jugal bifurcated to articulate with the quadratojugal
　　2.4.2. Character states that might diagnose Dinosauria
　　　2.4.2.1. Brevis fossa/shelf
　　　2.4.2.2. at least three sacral vertebrae
　　2.4.3. Character states that clearly do not diagnose Dinosauria
　　2.4.4. Feathers: a dinosaur innovation?
3. Geological setting for the origin of dinosaurs
　3.1. Dating the origin of dinosaurs
　3.2. The paleoenvironmental of early dinosaurs
　3.3. Early dinosaur-bearing formations
4. Dinosaurs of the Late Triassic and Early Jurassic
　4.1. Ambiguous taxa: Eoraptor and Herrerasauridae
　4.2. Theropods
　　4.2.1. Late Triassic theropods - fossil record and distribution
　　4.2.2. Late Triassic theropods - paleo biology
　　4.2.3. Early Jurassic theropods - fossil record and distribution
　　4.2.4. Early Jurassic theropods - paleobiology
　　4.2.5. Theropods across the Triassic/Jurassic boundary
　4.3. Sauropodomorphs
　　4.3.1. Late Triassic sauropodomorphs - fossil record and distribution
　　4.3.2. Late Triassic sauropodomorphs - paleobiology
　　4.3.3. Early Jurassic sauropodomorphs - fossil record and distribution
　　4.3.4. Early Jurassic sauropodomorphs - paleobiology
　　4.3.5. Sauropodomorphs across the Triassic/Jurassic boundary
　4.4. Ornithischians
　　4.4.1. Late Triassic ornithischians - fossil record and distribution
　　4.4.2. Late Triassic ornithischians - ghost lineages and diversity
　　4.4.3. Late Triassic ornithischians - paleobiology
　　4.4.4. Early Jurassic ornithischians - fossil record and distribution
　　4.4.5. Early Jurassic ornithischians - paleobiology
　　4.4.6. Ornithischians across the Triassic/Jurassic boundary
　4.5. Taxa often mistaken as dinosaurs
5. The dinosaur radiation: a historical review
6. The macroevolutionary pattern of the dinosaur radiation
　6.1. Introduction
　6.2. Lineage origination, cladogenesis, and phylogeny
　6.3. Taxonomic diversity and significant diversification shifts
　6.4. Morphological disparity and morphospace occupation
　6.5. Faunal abundance
　6.6. Rates of morphological change
7. The evolutionary radiation of dinosaurs: current status
8. The evolutionary radiation of dinosaurs: future directions
Acknowledgements
References