Dinosaur | Definition, Types, History, Names, & Facts | Britannica
Dec 9, 2024 · Dinosaur, the common name given to a group of reptiles, often very large, that first appeared roughly 245 million years ago and thrived worldwide for nearly 180 million years. Most died out by the end of the Cretaceous Period.
Dinosaur - Reptiles, Extinction, Fossils | Britannica
Dec 9, 2024 · Dinosaur - Reptiles, Extinction, Fossils: The chief difference between the two major groups of dinosaurs is in the configuration of the pelvis. The two dinosaurian orders were named Saurischia and Ornithischia in 1887. Saurischians range from the Late Triassic to the present day and include Sauropodomorpha and Theropoda.
Dinosaur - Evolution, Classification, Extinction | Britannica
Dec 9, 2024 · Dinosaur - Evolution, Classification, Extinction: After dinosaurs were recognized as a new type of fossil animal, popular fascination with them reached a peak in the 1850s with the first attempts to reconstruct Iguanodon, Megalosaurus, and Hylaeosaurus.
Dinosaurs Portal | Britannica
Dinosaur, the common name given to a group of reptiles, often very large, that first appeared roughly 245 million years ago (near the beginning of the Middle Triassic Epoch) and thrived worldwide for nearly 180 million years.
Classification of dinosaurs and theories for their extinction
Dinosaurs are classified as either ornithischians or saurischians, based on pelvic girdle structure. Most had a long tail, which they held straight out, apparently to maintain balance. Most, if not all, were egg layers.
dinosaurs at a glance - Kids | Britannica Kids | Homework Help
From studying these remains, scientists think that dinosaurs were the ancient relatives of today’s crocodiles, snakes, lizards, and birds. Below is a guide to some well-known dinosaurs. The first section groups dinosaurs by type.
Dinosaur - Extinction, Fossils, Evolution | Britannica
Dec 9, 2024 · Accordingly, certain groups of dinosaurs, such as the ornithopods, included a succession of types that were increasingly adapted for efficient food processing. At the peak of the ornithopod lineage, the hadrosaurs (duck-billed dinosaurs of the Late Cretaceous) featured large dental batteries in both the upper and lower jaws, which consisted of ...
6 Awesome Dinosaur Species You Should Know | Britannica
This Encyclopedia Britannica animals list features 6 awesome types of dinosaurs.
Dinosaur - Extinction Causes, Evidence, & Theory | Britannica
Dec 9, 2024 · Dinosaur - Extinction Causes, Evidence, & Theory: The mass extinction of dinosaurs 66 million years ago remains a misconception; the fossil record shows that dinosaurs were already in decline during the late Cretaceous.
Cretaceous Period | Definition, Climate, Dinosaurs, & Map
Dec 13, 2024 · Dinosaurs were the dominant group of land animals, especially “duck-billed” dinosaurs (hadrosaurs), such as Shantungosaurus, and horned forms, such as Triceratops. Giant marine reptiles such as ichthyosaurs, mosasaurs, and plesiosaurs were common in the seas, and flying reptiles dominated the sky.